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05.14.14Torah Science Foundation _ Torah of Life _ Biology Book _ Pilot 2 - Combo Chapters

Torah of Life _ Combo _ Nutrition & Nervous System Chapters

The Tor ah of LifeAn Integrated Torah-biology Textbook For Jewish High Schools

rabbi YiTzchak GinsburGh

Professor eLiezer zeiGer

New Chapter

The nervous sYsTem





Torah of Life – An Integrated Torah-biology Textbook

art on Cover - “Light from the Einsof* by Tuvia Katz

rabbi Yitzchak Ginsburgh is our generation’s most respected authorityon a unified view of Torah and

science. he excels in the understanding of many scientific disciplines and their connection to kabbalah and chassidic philosophy. he is the author of more than one hundred books in hebrew and english, including The Hebrew Letters, The Mystery of Marriage, Body, Mind and Soul, and The Art of Education. rabbi Ginsburgh is outstanding in his ability to teach ancient Torah knowledge in the language of our times.

about the authors

Professor eliezer (eduardo) Zeiger is Professor emeritus of biology at theuniversity of california,

Los angeles, and has written about one hundred scientific papers. he is the co-author of a leading textbook in plant biology that has been translated into ten languages and published in five successive editions. Professor zeiger has been a student of rabbi Ginsburgh since 1992, and is the founder and ceo of The Torah science foundation.

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Chapter 08 – Nutrition

introduction

biology is the study of life. in the Garden of eden there were two trees: the Tree of Life and the Tree of knowledge. a tree, with its roots, trunk, branches, foliage, and fruit, symbolizes a developmental program that starts with a germinating seed and culminates in fruits and new seeds. The Tree of Life symbolizes the creation of life, and the evolution of life from the perspective of the Torah.

“knowledge” in hebrew also means “consciousness.” The Tree of knowledge of Good and evil symbolizes the “tree” of conscious living forms, the pinnacle of which is man. The Torah is both the unfolding story of life and the unfolding story of human consciousness. it bestows life on those who walk in its path and corrects our state of consciousness, teaching us to know what is good and what is not, and to focus on what is good. Thus we may say that the Tree of Life is the “tree” of integrated Torah-biology and the Tree of knowledge is the “tree” of integrated Torah-psychology and the understanding of human consciousness.

integration of Torah and science requires a common frame of reference, a model that fits both Torah and science. The foundation of this model is the essential unity of the creator and his creation. The language of this model is provided by kabbalah, the most “scientific” aspect of the Torah. kabbalah provides the language that reveals the correspondence

between key Torah concepts and their scientific counterparts. at the core of this unifying language are the sefirot (often referred to themselves as the Tree of Life), the lights and channels of both life and consciousness that flow from the creator to his creation.

in contrast to the all-encompassing unity of the creator and his creation, ordinary reality appears fragmented and devoid of purpose. biology courses in Jewish schools often reflect this fragmentation, describing a reality in which the presence of the creator is completely hidden.

We present here a pilot chapter of a Torah-biology textbook aimed at properly reflecting the true unity of creation. biology, the science of life, is optimally suited for that purpose. The chapter alternates between science and Torah knowledge, always aiming at their integration. The ultimate purpose of this approach is to create a divinely oriented consciousness, which should help bring us back to the unadulterated consciousness state of the Garden of eden.

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Table of contents

Chapter 1

The science of biology

Chapter 2

The chemistry of Life

Chapter 3

cell structure and function

Chapter 4

Photosynthesis

Chapter 5

cellular respiration

Chapter 6

cell Growth and Division

Chapter 7

Genetics, Dna and rna

Chapter 8

nutrition

Chapter 9 human Genetics

Chapter 10

scientific evolution and Torah evolution

Chapter 11

The history of Life

Chapter 12

Life Diversity

Chapter 13

animal behavior

Chapter 14

The human body

Chapter 15

The nervous System

Chapter 16

skeletal and muscular systems

Chapter 17

circulatory and respiratory systems

Chapter 18

Digestive system

Chapter 19 endocrine and reproductive systems

Chapter 20 immune system

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Chapter 08

FIGUre 8.1

Typical Foods Served on Jewish Holidays

Clockwise: matzah (unleavened bread), for Passover, “blintzes” traditionally served stuffed with a cheese filling on the festival of Shavuot; apples dipped in honey served at the first meal of Rosh Hashanah; “latkes” fried in oil served during Chanukah; we drink wine and eat hamantashen on Purim; and challah bread prepared in honor of Shabbat and holidays.

In tHIS CHaPter

• FoodandEnergy

• Nutrients

• NutritionandaBalancedDiet

• SourcesandReferences

nutrition

800



© Torah Science Foundation


To see how important food is for most people, have a look at the groups of people eating in a park on a national holiday. eating is a primary human activity. We all need to eat because we feel hungry if we don’t. Plus, prolonged periods without eating result in starvation and bodily damage.

but food is even more than the nutrition it provides. food is a basic aspect of human culture. in many celebrations, such as Thanksgiving Day, a meal serves as the focal point for a festive gathering of people.

food is primarily nourishment, but to the human psyche, physical nourishment suggests the need for spiritual nourishment as well. expressing thanksgiving nourishes the soul, just as food nourishes the body. if we sit together, enjoy the presence of each other, tell stories, make plans, and then join in a meal, a snack, or a drink, our hearts can open. sharing food together makes us more receptive and able to interrelate productively with one another.

in Jewish tradition each holiday has a special food that symbolizes the inner meaning of the day (fiGure 8.1). While eating the food, we consciously internalize that meaning. on Pesach, the holiday commemorating our liberation from egyptian slavery, we eat matzah — unleavened bread — symbolizing bondage and redemption. on shavuot, the time of the Giving of the Torah, we eat dairy products, for the Torah is likened to milk. on rosh hashanah, the new Year, we eat an apple dipped in honey to symbolize our desire for a sweet year. on chanukah, we eat latkes and cheese, reminding us of the heroism of Yehudit and the maccabees. on Purim, we drink wine and eat hamantashen, commemorating the feast of esther and the hanging of haman.

Food and energyWhy is food so important for our physical well being? everything we do during the day, such as walking, working, playing, or even thinking, requires energy, and food is the substance which fuels our daily activities. a major component of food is the chemical glucose. We learned in an earlier chapter that cells convert glucose and other molecules into aTP, and aTP is the chemical fuel of the cell (fiGure 8.2).

H

Adenine

Ribose

Phosphate Groups

C C

CN

C H

N

H HC

OH

H

C

OH

H

O

C

H2C O P

O

O P

O

O P

O

O O O

O H

N

N

C

NH2

H H H

ATP Adenosine triphosphate C10H16N5O13P3

C

Energy Rich Bond

FIGUre 8.2

ATP, Adenosine triphosphate

ATP is a chemical compound consisting of the nucleotide adenine, the five-carbon sugar, ribose, and three phosphate groups. The breaking of the chemical bond between the second and third phosphate group releases a relatively large amount of energy that is used by the cell to fuel many energy-requiring processes

801




Chapter 08 – Nutrition802

Water

BurningFood

Ignition WiresThermometer

FIGUre 8.3

Calorimeter

A calorimeter measures the heat released by a substance, in our case, food, when the substance is burned. From that information it is possible to calculate the calorie content of the food being burned. One ounce of regular potato chips contains 150 calories. One ounce of cheese sandwich made with commercial white bread, cheddar cheese, and margarine contains 115 calories.

most people go about their daily routine of providing for their bodies what nature requires — eating, drinking, sleeping etc. — without paying much attention to what these activities and functions mean on a spiritual plane. The questions that we need to ask are: Why did God create me this way? Why do I have to eat in order to obtain energy?

The Torah teaches us: “man does not live on bread alone, but rather man lives on the word of the mouth of God.” in the Torah, the word “bread” refers to food in general. What the above verse is teaching us is that the “bread” we eat contains a Divine life force, and moreover, that it is important for us to know that this life force is coming directly from God, the creator and sustainer of all life (and indeed, of all reality).

if we eat our food with this realization in mind, we can extract the Divine life force or Divine spark that is the inner essence of the food. as a result, the level of nutrition — both physical, as well as cognitive and spiritual — that we gain from the food will be much greater than if we eat without this understanding.

in hebrew, “bread” (food), lechem, is related to “war,” milchamah (both words come from the same root l-ch-m). The sages instruct us to eat “with a sword in hand.” What does this mean?

The “sword” is the consciousness necessary to pierce through the outer “shell” of the food and reveal, i.e., redeem, the Divine spark trapped within it. on the physical plane, the “sword” symbolizes the enzymes present along the digestive track that chemically break down the food and allow for the body to absorb its nutrients. The Torah teaches us to be conscious of what takes place within our bodies, to recognize the spiritual implications of the physiological processes that are responsible for our life and health. The Torah wants us to connect in our consciousness that which is taking place on the spiritual plane with that which is simultaneously taking place on the physical plane, thus enriching both — more spiritual nourishment and more physical nourishment.

if i am trying to avoid overeating and i have the choice between eating a bag of potato chips or a cheese sandwich, which one should i choose? one way to quantify the energy content of food is, surprisingly, to burn it! in the body, food is processed very slowly by enzymatic reactions that metabolize the food, step by step. in an automobile, the hydrocarbons in gasoline are burned to power the car’s engine.

if we want to quantify the available energy in potato chips or a cheese sandwich, we burn comparable amounts of the two types of food in an instrument called a calorimeter (fiGure 8.3), and measure the amount of heat released in units called calories. one calorie is the amount of heat needed to raise the temperature of 1 gram of water by 1 degree celsius. it is convenient to express the energy in food as kilocalories (kcal); one kcal equals 1,000 calories. in food, one kcal is referred to as a dietary calorie, with a capital c. if you are an average-sized teenage girl, you will burn about 2,200 calories per day (2,800 calories per day for males). if you are playing in a tournament and you engage in vigorous physical activity, you will burn more calories.




Torah of Life – An Integrated Torah-biology Textbook 803

The burning of food immediately brings to mind the holy Temple in Jerusalem, where numerous sacrifices were burnt on the altar every day. The burning elevated the energy trapped in the sacrifice (from the animal, vegetable, and mineral kingdoms) to a higher spiritual plane, dedicating it to holiness and purity.

in the Temple service, the body of the sacrifice was offered up for God. because of the very high level of consciousness of the Jewish People that prevailed when the Temple existed, we saw ourselves reflected in the sacrifice, burning up for God, as it were. We experienced nature returning to and reuniting with its Divine source.

When we lost this high level of consciousness, the Temple was destroyed, for we were no longer worthy of it and its Divine service. nevertheless our sages teach us that every table at which we eat symbolizes the altar in the Temple where the sacrifices were burned. knowing that nowadays our table is symbolic of the altar of the Temple, and that the food we consume releases energy in a way similar to a sacrifice adds a powerful new dimension to our meals. Whenever we eat, we should have in mind that we are raising the energy of the food in an offering to God, and that we intend to use the energy that we obtain from the food to serve God.

for a Jew, only kosher food truly releases its energy in an optimal manner conducive to serving God. only kosher food can raise our level of consciousness to recognize God’s Presence in our lives and devote our lives to his service. maimonides teaches that eating kosher food is the truly healthy way for a Jew to live (fiGure 8.4).

The power of will in our soul is likened to fire and expresses our burning passion to achieve a goal. The sages teach that “nothing stands before (the force of one’s) will,” and “there is nothing as forceful as will.” aligning our will to God’s makes for a healthy soul. God tells us what we may eat and what we may not. by obeying his will and making his will our will, we strengthen our souls. a strong soul strengthens the body in which it resides.

There are mammals that are kosher and those that are not. The same goes for birds, fish, and insects (certain grasshoppers are kosher). in general, those species that are not kosher display negative characteristics in their lifestyle, such as cruelty, either in the form of preying on other animals or parasitism. We do not want to incorporate these negative traits into our systems by consuming those non-kosher species.

in hebrew, the language of creation, the word for “life,” or “life force,” chaim, is related to the word for “heat,” chom. The ba’al shem Tov, the great Jewish leader and founder of the chassidic movement, used to place his hand on the heart of a child and bless him: “be a warm Jew.”

in the Temple, fire would descend from heaven to consume the sacrifices offered on the altar. Likewise, when eating we should have in mind to connect with the essence of this holy fire. connecting to this fire warms the heart, making it burn with desire to serve God. The ba’al shem Tov used to send his disciples to observe how simple Jews eat with the pure, innate intention of “burning up” the energy in the food for God.

FIGUre 8.4

Kosher Symbols

Some of the many kosher symbols found in food labels, informing the consumer that a rabbinical authority certifies that the labeled food is kosher. The OU symbol from the Union of Orthodox Jewish Congregations is one of the oldest in the United States and certifies over 300,000 products worldwide.





a person running a marathon will utilize a significant amount of energy. most of that energy will be used to generate aTP, to drive muscle movement. in addition, proteins are degraded under intense exercise, and there is also protein synthesis. ingested food provides the raw material for these processes, including building blocks needed to repair and rebuild existing tissue. besides proteins and their amino acid components, food is the source of the building blocks needed to manufacture cell membranes and the genetic material Dna.

most organisms, however, are limited in their ability to manufacture some essential building blocks. There are at least 45 substances needed by the human body that it cannot manufacture on its own. in mammals, these include eight amino acids needed to build essential proteins that must be obtained from ingested food. humans obtain amino acids by breaking down ingested proteins. another source of amino acids is the breakdown of existing body proteins which are in constant turnover, as the tissues of the body undergo renewal.

mammals are unable to manufacture acetyl groups–c 2h3o (fiGure 8.5). The acetyl groups are very common in food and ingested acetyl groups are found in a large number of different molecules.

The concepts related to food and its metabolism are studied in the science of nutrition. The studies seek to determine optimal diets and the quality and quantity of food needed by the body. nutritionists also plan diets for people with special needs, such as diabetics.

nutrientsnutrients are substances in food that supply the energy and raw materials your body uses for growth, repair, and maintenance. The nutrients that the body needs are water, carbohydrates, fats, proteins, vitamins, and minerals.

From Food

Amino Acids

Oils

Vitamins

Acetyl GroupCarbon Skeleton

Citrate

Vitamin A

H C

OH

H

C

HO COOHC

COOH

H C C OOH

H2C

H3

H3

CH3

CHC

C

C

C

H2

H2

C

C

CH2

C

C

C

C

C

CCH

C

C

H HHH H

H2OH

H3C

C

FIGUre 8.5

The Acetyl Group

Mammals lack the enzymes needed to synthesize the acetyl chemical group and must ingest it. The acetyl group is very abundant in many food sources and used in many different molecules. It is found in Vitamin A, in the important intermediary of respiration, citrate, and many amino acids, oils, and vitamins. The acetyl group is an important example of the dependency of humans on food for their nutritional needs.





Water

Water is the most important nutrient. at birth, a human baby may be composed of up to 90% water, with water making up about 70% of an adult. most of the chemical reactions in living organisms occur with the reactants dissolved in water, and water is the universal solvent on earth.

Plant seeds with very low water content can live for centuries in a dormant stage. once the seed is hydrated, metabolism is activated, the seed germinates, and either it is successfully established in a humid environment or it dies. Terrestrial plants are continuously losing water through the leaf surfaces in a process called transpiration. on a summer day, leaves of well-irrigated plants are usually significantly cooler than the surrounding environment, due to the cooling effects of transpiration. This is because liquid water absorbs energy when it evaporates at the surface of the leaf, and it cools it. Without the cooling effect of transpired water, plants growing in full sunshine would overheat.

in mammals, including humans, water loss through sweating plays an important role in the control of body temperature. sweat glands remove water from body tissues and release it as sweat. in a process similar to leaf transpiration, the water in sweat evaporates, and it cools the body. Water vapor is also lost from the body during breathing. it is generally recommended that humans drink between one and two liters of water per day. if the water lost is not replaced, the body dehydrates, and the dehydration causes problems with the circulatory, respiratory, and nervous systems.

Water is linked to the sefirah (our faculty) of wisdom, which is the first power of the conscious intellect (“revealed mind”). Wisdom manifests in the soul as flashes of new insight into truths that lie at the core of reality. Like water, which flows downhill from a high place to a low place, the insights of our wisdom flow down from their source in our super-conscious “concealed mind,” and continue to flow downhill to permeate all the conscious powers of our souls.

Wisdom (water) is referred to as “the point that is present uniformly throughout the body.” it corresponds to the letter yud (י), which resembles a point, the first letter of the Tetragrammaton (God’s four-letter name).

Water is the source of life, and the water we drink becomes part of our life force. in the Torah, spring waters are called “living waters.” spiritually, wisdom is the source of life, as in the verse “wisdom gives life,” and so the study of Torah (Divine wisdom) is also likened to water. in the words of the sages: “Water refers to the Torah.”

so many different substances dissolve in water that, as we saw earlier, it is called the universal solvent. Likewise, all secular knowledge dissolves in the water-wisdom of the Torah. The goal of the Torah is to unite, and in our generation, our goal is the unification of Torah and science.





Carbohydrates

carbohydrates are the main source of energy in food. You may recall that most carbohydrates have the general chemical formula: cn (h2o)n. The name of these compounds means hydrates of carbon.

simple carbohydrates include glucose and fructose, early products of photosynthesis in plants that are very common in fruits, honey, and sugar cane. complex carbohydrates are large chains (polymers) of simple sugars (fiGure 8.6a-c). starch is a common complex carbohydrate found in grains, potatoes, and vegetables. Plants store large amounts of glucose and other simple sugars synthesized by photosynthesis in the starch, which is later found in storage organs like potatoes, or as reserve food for seeds, such as grains. When the seeds germinate, they utilize the starch as food to grow in the early stages of germination, until the seedling is able to photosynthesize and generate new sugars.

We eat starch when we eat bread, pasta, and potatoes. starches are broken down in our digestive system and simple sugars, such as glucose, are released. The sugars are absorbed by the bloodstream and carried to all cells of the body. The breakdown of glucose through the process of respiration supplies readily available energy for all cellular needs.

animals store excess simple sugars in the complex carbohydrate glycogen, which is abundant in the liver and in skeletal muscle. Like starch, glycogen is a branched polymer of glucose. small concentrations of glycogen can be found in the kidneys, in some glial cells of the brain, and in white blood cells.

Like the starch stored in seeds of plants, the uterus stores glycogen during pregnancy to nourish the embryo. When we eat a carbohydrate-rich meal such as pasta, blood glucose increases and glycogen is made in the liver. When glucose levels drop and energy demand increases, glycogen is broken down and the glucose from liver glycogen becomes the energy source for the body.

another important complex carbohydrate that is also a polymer of glucose is cellulose. Plant cells have walls that are mostly built of cellulose. cellulose is the most common organic compound on earth, and about 33% of all plant matter is cellulose.

O O

H

CH2OH

H

OH

OH

H

O

H

O

O

H

OH

H

H

OH

CH2OH

HH

H

O

H

CH2OH

H

OH

OH

H

O

H

O

O

H

OH

H

H

OH

CH2OH

HH

H

FIGUre 8.6b FIGUre 8.6c FIGUre 8.6a

Complex Carbohydrates

Glucose molecules can link to each other (FIGURE 8.6a) forming giant polymer chains (Figures 6b and c). Cellulose is made of parallel linear chains (FIGURE 8.6b). Starch (FIGURE 8.6c) and glycogen (not shown) are made of branched chains.





can you guess which is the cellulose-made material most common in your life? The answer is paper.

ruminants, such as cows, digest cellulose with the help of micro- organisms that live in their guts. humans, on the other hand, can digest cellulose only to a very small extent. however, cellulose is important in our diet as dietary fiber helping bulk food and waste move through the digestive system. foods rich in fiber include whole-grain bread, bran, and many fruits and vegetables.

What comes to mind when we hear the word “carbohydrate”? many people will immediately think of bread. observant Jews who are about to eat bread will first wash their hands, say the blessing “al netilat yada’im,” and then bless the bread with the blessing of “hamotzi.” only then, the bread is eaten.

besides “hamotzi lechem min ha’aretz,” the blessing for bread, there are other blessings for different foods. We say “borei minei mezonot” for foods such as pastry or pasta, “borei pri ha’adama” for vegetables, and “borei pri haetz” for fruits from trees. however, if we are about to partake of a shabbat or festive meal, we first wash our hands and eat bread after the “hamotzi” blessing. The blessing of the bread will cover all the other foods we eat at that meal, which we would otherwise bless over separately if we were sitting down to a meal at which no bread was served.

What is unique about bread that makes it the all-inclusive food? The central role of bread for our forefathers is very clear in the Torah. malchizedek, the king of shalem, welcomed abraham our father with “bread and wine” when abraham returned from his victory over the four allied kings (Genesis 14:18). abraham offered “a morsel of bread” to the three angels who visited him in the guise of wayfarers, and he hurried sarah to knead and make cakes out of fine flour (Genesis 18:5-6).

We noted earlier that water is associated with the sefirah of wisdom, the first power of the intellect. food is associated with the next, complementary power of the intellect, the sefirah of binah, understanding, which corresponds to the first hei (ה) of the Tetragrammaton. The numerical value of the letter hei is five. Wisdom and understanding are compared to father and mother.in the context of our study of nutrition, the father (wisdom) provides the life-giving water, and the mother (understanding) provides the five basic nutrients — carbohydrates, proteins, fats, vitamins, and minerals (fiGure 8.7). These correspond to the five basic emotions of the soul, already present within the spiritual womb of understanding. bread, the primary source of carbohydrates in our diet, corresponds to the first of our soul’s emotive attributes, loving-kindness. in the idiom of the Zohar, the classic text of kabbalah (the inner dimension of the Torah), loving-kindness is called the “day” (referring to the first day of creation) “that accompanies all days” (the remaining days of the week). The Zohar is teaching that the light created on the first day illuminates and activates all succeeding stages of creation. all meals begin with bread and bread accompanies all the portions of the meal.

FIGUre 8.7

The Five Sefirot

The sefirah of binah is associated with food and it is connected with the five emotive sefirot of chesed (carbohydrates), gevurah (proteins), tiferet (fats), netzach (vitamins), and hod (minerals).

hodacknowledgment

(minerals)

tiferetbeauty(fats)

gevurahmight

(proteins)

netzachvictory

(vitamins)

chesedloving-kindness(carbohydrates)





as discussed above, we aspire to eat with the consciousness of making our table an altar, in which the Divine force inherent in food, particularly bread, is extracted to nourish our body, both physically and spiritually. We emulate the kohanim, the priests of the Temple, by washing our hands before approaching the altar, and blessing God, the Giver of the bread, before we eat it.

Proteins

customarily meat is served on joyous occasions. one of the ways in which meat differs from other foods is its high protein content. meat is mostly muscle from an animal, which is usually 75% water and 20% protein (typically, a pasta dish is less than 10% protein).

You may recall that proteins are polymers of amino acids. in the protein polymer, the amino group of an amino acid is bonded to the carboxyl group of the next. There are 20 common, naturally occurring amino acids, and different combinations of amino acids specify the properties of the hundreds of thousands of proteins that exist in living organisms (fiGure 8.8).

Proteins are essential for life, and all enzymes are proteins. enzymes, such as proteases and amylases, are needed for protein and carbohydrate digestion. The protein hemoglobin transports oxygen from the lungs to the rest of the body, and the protein insulin regulates sugar levels in the blood. The chloroplast protein rubisco, thought to be the most abundant protein on earth, catalyzes the binding of carbon dioxide to one of the calvin cycle intermediates that is part of the cycle driving carbon dioxide fixation and the synthesis of carbohydrates by plants. When a person eats a teaspoon of honey, the sugar found in the honey will readily enter the bloodstream and be used as a source of energy. The digestive process with ingested proteins is very different. enzymes present in the stomach digest the proteins and individual amino acids are released. The amino acids reach the blood stream and are distributed to many cells of the body, where new proteins will be synthesized following the genetic program of the organism.

of the 20 common amino acids (fiGure 8.9a) that the body needs to synthesize its own proteins, 12 can originate from ingested food or be made by the metabolic machinery of the body. The other eight are essential amino acids that the body cannot make and must be ingested (fiGure 8.9b).

FIGUre 8.8

Proteins

Proteins are polymers of amino acids. Amino acids join each other by peptide bonds between their amino end and their carboxyl end.

ValH3N+Amino Group

Carboxyl GroupCOO-

Arg Lie Cys

S

S

Glu LeuGly

Ala

GinSerAsp

CysLys

Asn

Val

His

Pro

Phe Leu LysThr

Tyr

H

H

O

O-

H

CH3

H2N C C H2N

O

O-

C

O

H+ H

Glycine Alanine Peptide Bond between Glycine and Alanine

H

H H

H

CH3

H2N C

O-

CC N C

O O

FIGUre 8.9a

The 20 Common Amino Acids

There are 20 common amino acids, listed in the table. Proteins can consist of a few to several thousand amino acids. For example, hemoglobin, the oxygen carrying blood protein, has 574 amino acids.

Amino ACid Abbr.

Alanine Ala

Arginine Arg

Asparagine Asn

Aspartic Acid Asp

Cysteine Cys

Glutamine Gln

Glutamic Acid Glu

Glycine Gly

Histidine His

Isoleucine Ile

Leucine Leu

Lysine Lys

Methionine Met

Phenylalanine Phe

Proline Pro

Serine Ser

Threonine Thr

Tryptophan Trp

Tyrosine Tyr

Valine Val





food sources with complete proteins (containing all the amino acids) include meat, eggs, milk, and fish, and the milk products yogurt and cheese. soybeans are the only vegetable considered to be a source of complete protein. a combination of legumes with grains, such as beans and rice or corn, can provide a source of complete protein.

Proteins correspond to the emotive sefirah of might and the inner experience of fear. When we refer to the sefirot, our frame of reference is the human soul. What is the connection between the human soul, the sefirot, and the creation of the universe?

understanding of these relationships is itself a central purpose of creation. The Torah teaches us that humans are the pinnacle of the creative process. This is not meant to make us feel arrogant. on the contrary, the Torah instructs us to emulate the great Jewish leader, moses, the humblest man ever to walk the face of the earth.

God loves us and wants us to love him and recognize him as the master of the universe. Why would God, an infinite and all-powerful being, care? Though we can never really know the answer to this question, we can only say that God does care, and desires, for our eternal good, that we become conscious partners with him to better the world in which we live by first understanding, to the best of our ability, the purpose behind creation.

acquisition of a rectified state of consciousness is greatly aided by understanding the origin of the universe. The Torah teaches us that at the beginning there was only God, and that he first manifested pure, simple light. The creative process continued with a progressive attenuation of the pure, Divine light and its enclosure in material form.

one of the early stages of creation (a continual, ongoing process) is the manifestation of the vessels of the ten sefirot, and the enclosure of the pure, Divine light within them. The light corresponds to the soul and the vessels to the body. in the early stages of creation, the body is totally transparent and “null” to the soul within it. The only consciousness is that of the soul, the consciousness that God is one and that there is no other besides him. The creative process culminates with the creation of ordinary reality, in which the Divine soul is completely hidden and the body is fully manifest.

The description of the sefirot as attributes of the human soul reflects the fact that the human being is a microcosm of the universe. as the vessels of the sefirot descend from level to level they break the simple, “white” Divine light into an observable spectrum of colors. The three primary emotions of loving-kindness, might, and beauty — corresponding to the three basic nutrients: carbohydrates, proteins, and fats — correspond to the artist’s three primary colors of blue, red, and yellow.

carbohydrates correspond to loving-kindness and the color blue. Proteins correspond to might and the color red. fats correspond to beauty and the color yellow. (fiGure 8.10).

We can visualize the red nature of proteins by thinking of red meat or red lentils (an excellent source of protein). our patriarch Jacob prepared a red lentil soup to console his father, isaac, upon the passing of his grandfather

Isoleucine

Leucine

Lysine

Methionine

Phenylalanine

Threonine

Tryptophan

Valine

FIGUre 8.9b

List of eight essential amino acids.

FIGUre 8.10

The Sefirot and the Colors of the

Spectrum

Each sefirah is associated with a color. Here we show the relationship between the three primary emotive sefirot and the three primary colors: Chesed, loving-kindness (carbohydrates) is blue; Gevurah, might (proteins) is red; and Tiferet, beauty (fats) is yellow.

tiferetbeauty(fats)

gevurahmight

(proteins)

chesedloving-kindness(carbohydrates)





abraham. abraham is associated with loving-kindness (carbohydrates and the color blue), isaac with might (proteins and the color red), and Jacob with beauty (fat and the color yellow). esau, Jacob’s twin brother, symbolic of profane might and fear, came tired from the field and asked Jacob to pour into his mouth “the red, the red,” for which reason esau became known as “the red one.”

Why can the human body synthesize only 12 of the common 20 amino acids, and not the other eight essential amino acids? The Torah teaches that the universe is comprised of four different kingdoms: the mineral kingdom (dust and rocks), the vegetable kingdom (plants), the animal kingdom (animals, fish and insects), and the human kingdom, which the Torah calls medaber, “the speaker.” This division is hierarchical: the world of dust and rocks is the lowest level, and the human world (the world of fully developed consciousness manifested in speech) is the highest.

humans have a critical role in the unification of the four kingdoms and this role is connected with nutrition. by extracting the physical nutrients and spiritual “sparks” from their environment — the lower realms of reality in the mineral, vegetable, and animal kingdoms — and “ingesting” them, humans elevate the nutrients and sparks from the lower worlds and transform them into vital human energy.

at the same time, plants and animals have a primordial vital energy that, in a certain spiritual sense, originates from a source higher than the origin of the human soul itself! That’s why we humans need to consume plants and animals to sustain us, and provide us with necessary nutrients, beginning with the eight essential amino acids that we cannot produce ourselves or obtain in any other way! in particular, the amino acids we miss are necessary to make proteins, and indeed it is explained that the superior spiritual origin of the food we eat in relation to ourselves lies in the sefirah of might, corresponding to protein.

Fats

most of us enjoy having a breakfast in the morning that may include a glass of milk, bread, and butter or margarine. We learned about bread in the carbohydrates section. What about butter or margarine? They’re fats or lipids.

You may recall that fats are made of fatty acids and glycerol. Depending on their chemical structure, fats can be solid or liquid at room temperature. The oil people use in salads is a liquid fat. butter, margarine, and other fats are solid. fats are a very rich source of energy; one gram of fat contains about nine calories (a gram of sugar contains less than half of that amount). fatty acids are highly reduced and their oxidation generates abundant aTP per unit of mass. hibernating animals eat more than usual in the fall and store the food energy as fat, which they use during the winter.

Glucose levels in the blood are tightly regulated by hormones, such as insulin and glucagon, which control the metabolism of carbohydrates and fats. When blood sugar is low, fatty acids are transported to the cells that need energy, such as muscle cells. The fatty acids are broken down and oxidized





in the cell mitochondria. The oxidation generates aTP that supplies energy for cellular work. When blood sugar is high, liver and muscle cells store the surplus glucose as glycogen. if glycogen depots are full and food intake remains high, fatty acids are made and stored.

in our diet-conscious times, some people try to eliminate fats from their food, yet fats are very important for our health. fatty acids, such as linoleic acid (fiGure 8.11), are essential nutrients because the metabolic machinery of the human body cannot manufacture them; essential fatty acids must be ingested. some vitamins, such as vitamin a, an important vitamin for night vision, are fat-soluble and can only be absorbed and transported together with fats. Linoleic acid and other fatty acids are also essential for the building of cell membranes and myelin sheaths. fat tissue insulates the body and protects critical organs, such as the heart and kidneys.

however, an excess of fat in our diet can have serious consequences, including obesity, diabetes, and heart disease. You may recall that fatty acids differ in the number of hydrogen atoms bonded to the chain of carbon atoms. if every carbon atom in the chain is bonded to two hydrogen atoms, the fatty acid is called “saturated.” if at least one carbon atom in the chain is bonded to a single hydrogen atom, and it is bonded to a neighboring carbon atom by a double bond, the fatty acid is called “unsaturated.” for example, linoleic acid, mentioned earlier, has 18 carbon atoms and two double (unsaturated) bonds. fatty acids with more than one double bond are called “polyunsaturated.” nutrition authorities recommend a diet with a maximum of 30% of calories from fat, with no more than 10% of saturated fats.

it is well known that the human body hoards fat. When food intake is insufficient, the body will mobilize reserve carbohydrates; if this is not enough, it will use proteins, and only as a last resort, it will use stored fat. When the need arises, why is it that the body will rather consume muscle than stored fat? Despite its importance for the understanding of issues such as obesity, which is reaching near epidemic levels in developed countries, science has yet to find the reasons and the mechanisms underlying the hoarding of fat.

We can learn from the Torah about our relationship with fats. recall that carbohydrates are associated with the sefirah of loving-kindness. fats are associated with the sefirah of beauty (fiGure 8.7). The inner experience of beauty is compassion.

HO

O H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

C C C C C C C C C C C C C C C C C C H

Double Bond

Carboxylic Group

FIGUre 8.11

Linoleic acid.

The unsaturated fatty acid, linoleic acid, has 18 carbons and two double bonds. Linoleic acid is an essential fatty acid, that humans cannot manufacture and must ingest in their food for their nutritional needs.





The emotive attribute of compassion can be expressed in two ways — as prayer (beseeching God to be compassionate to us) and in being compassionate to others. The sages teach that in order to arouse God’s compassion one should first express compassion to others. Therefore, it is fitting to give charity to the poor before praying. compassion refers not only to the act of giving charity (an act of loving-kindness), but to the sense of empathy that motivates the act. To be compassionate is first and foremost to feel the plight of the other and identify with him. The ba’al shem Tov made compassion a pillar of the chassidic movement.

What does the Torah teach about fats? a “fat” body in the Torah denotes a healthy or “well-oiled” body. in today’s Western culture, a slim body is considered more beautiful, whereas in other cultures, a fat (although not obese) body is considered more beautiful.

as stated earlier, the health consequences of too much fat can be severe. Why, then, does the body hoard fat? We learned earlier that fat is a central component of cell membranes and of myelin sheaths covering the nerves. Thus fat protects your organs and insulates your body — actions that relate to “body-care” — beauty and its inner experience of compassion.

storing fat to be used later, when necessary, points to a fundamental affinity between the body and fat. storing away something to be used at a later date relates to the characteristic of patience, a trait that originates in the super-conscious level of our soul and manifests in the sefirah of compassion.

it is a common belief (which has been confirmed to a certain extent by recent scientific studies) that fat people tend to possess a more pleasant disposition, are more social, and more compassionate to others than are slim people. This clearly identifies fats with compassion. a pleasant and compassionate personality is also conducive to good physical health and less neurosis. (however, modern society can cause people to become neurotic about being fat.)

People eat (and often overeat) to calm down. but rabbi shneur zalman, the first rebbe of chabad, teaches that the in-depth study of Torah, particularly chassidic philosophy, is the best tranquilizer of the soul. so there is no need to eat in order to relax!

vitamins

vitamins are carbon-based, essential organic molecules that are required for normal growth and metabolism. Like the essential amino acids and fats, most vitamins must be obtained from food. in contrast to the essential amino acids and fats, vitamins are needed in very small amounts; a few milligrams per day will suffice. however, vitamin deficiency can have severe, even fatal consequences.

Thirteen essential vitamins have been identified in humans, and they can be divided into two categories: water-soluble and fat-soluble. The water-soluble vitamins include vitamin c and the b vitamins. Water-soluble vitamins cannot be stored in the body and must be obtained from food every day.





vitamin c deficiency causes scurvy, a disease characterized by bleeding gums, loss of teeth, and slow wound healing. before the discovery of vitamin c, sailors suffered from scurvy during long sea voyages. it was later learned that scurvy can be prevented by eating fresh vegetables and fruits.

The fat-soluble vitamins include vitamins a, D, e, and k. vitamin a is a component of visual pigments, vitamin D facilitates the absorption and metabolism of calcium and phosphorus, vitamin e is an antioxidant that prevents damage to cell membranes, and vitamin k facilitates blood clotting. in contrast to the water-soluble vitamins, the fat-soluble ones accumulate in body fat, so the stored vitamins can be used when their intake from food is insufficient. an over-abundance of water-soluble vitamins is excreted in urine and is generally harmless. on the other hand, an excess of fat-soluble vitamins remains in the body and can be toxic.

nutritionists study daily needs of vitamin intake, and the federal Drug administration publishes recommendations for daily allowances. some controversies have arisen surrounding these recommendations. for instance, the recommended daily intake of vitamin c is less than 100 mg, but some studies claim that a daily intake of 1,000 mg reduces the risk of cancer and cardiovascular diseases. more data is needed for definitive answers, but it is clear that a healthy lifestyle and a balanced diet eliminate most risks of vitamin deficiencies.

Minerals

minerals are simple inorganic nutrients and, like vitamins, are usually required in small amounts. in plants, the mineral manganese is required for the photosynthetic reaction that splits water and generates oxygen. most of the oxygen in the earth’s atmosphere, which is essential for all aerobic organisms, including humans, is generated by the manganese-requiring, water-splitting reaction in photosynthesis. Phosphorous is required for aTP and nucleic acids. iron is required by the cytochrome molecules that function in photosynthesis and in cell respiration, and for hemoglobin, the oxygen-binding protein of red blood cells. Potassium, sodium, and chloride are important for the regulation of the osmotic balance between cells and the outside environment. humans and other vertebrates require relatively large amounts of calcium for the building and maintenance of bone.

excess sodium intake can cause health problems. The maximum recommended daily sodium intake in humans is 2,300 mg., but many people may be consuming two to three times that amount. This is because packaged food may contain high amounts of sodium chloride, even if it does not taste salty. high sodium intake has been associated with high blood pressure. excess iron intake can cause liver damage. as stated earlier, a balanced diet which includes a variety of foods and sufficient fresh fruits and vegetables ensures a healthy lifestyle and will supply adequate levels of required minerals.

vitamins are associated with the sefirah of victory, and the inner experience of confidence. minerals are associated with the sefirah of acknowledgment, and the inner experience of sincerity. in kabbalah, confidence and sincerity are described as two sides of one coin. in the physical domain, vitamins and





minerals parallel this close relationship: both are essential for a healthy body and are used in small amounts.

God promised assistance to those who strive to be partners with him in creation and dedicate themselves to rectify the world. recall that fats are associated with compassion. Psychologically, the fat-soluble vitamins represent confidence based on the experience of compassion. This sense of self-confidence arises from our experience of God as always being near, always expressing his compassion towards us. This self-confidence is warranted because God is always eager to give us the power to succeed in achieving our life goals. here too, the physical plane mirrors the spiritual/psychological plane, because excessive amounts of the fat-soluble vitamins, just like over self-confidence, can be toxic.

in contrast, water-soluble vitamins must be obtained every day. on the spiritual plane, they represent total reliance and confidence in God, our father in heaven (note that water corresponds to wisdom, also known as the father principle, as mentioned above). The water-soluble vitamins nurture confidence that God will provide us with our needs every day.

sincerity implies simplicity, which in our context, alludes to simple, inorganic chemical elements necessary for our bodies to function properly. Like vitamins and minerals, confidence and sincerity function together as two partners, and in kabbalah, they are depicted as two legs,neither of which, when walking, can function without the other.

nutrition and a Balanced Dieta healthy diet involves consuming appropriate amounts of all nutrients, and an adequate amount of water. nutrients can be obtained from many different foods, so there are a wide variety of diets that may be considered healthy diets. a healthy diet needs to have a balance of carbohydrates, proteins, and fats, and adequate amounts of vitamins and minerals.

You should eat a variety of foods each day and limit your intake of fatty, sugary foods. read food labels before making your purchases so that you can choose healthful foods. a food label provides some general information about nutrition, listing the daily values and the calories per gram of carbohydrates, protein, and fats. The daily value shows you how the particular food fits into the overall diet. keep in mind that daily values are based on a 2,000-calorie diet.

nutritional needs are affected by age, gender, and lifestyle. rapidly growing adolescents and other groups of people need more nutrients than the daily values indicate. When choosing foods, you should use the information on food labels to compare with similar foods on the basis of their proportion of nutrients to calories. a desired food should be high in nutrition and low in calories.





Let us now see how the basic rules for a healthy physical diet translate into guidelines for a healthy spiritual life. as discussed earlier, foods rich in complex carbohydrates represent the emotive attribute of love for both God and mankind. Love is the first of the five emotions initially contained within understanding, inspired in the intellect. Just as complex carbohydrates are the basis of our physical diet, intellectually inspired love, derived from in-depth study of the Torah and meditative prayer, forms the basis of a healthy spiritual life.

You should limit your intake of fatty, sugary foods. Likewise, in the spiritual sphere, too much unregulated love (sugary foods) or compassion (fats) on yourself may have a negative influence on your overall well-being.

as explained above, the energy released from the food that we eat will help us mature in character and ascend in our service of God. a Jew should strive to eat kosher food according to the laws of the Torah.

a healthy body requires a healthy soul — the two are totally interdependent. in hebrew, the initials of “body” (guf) and “soul” (neshamah) spell the word for “garden” (gan). a well balanced diet, together with proper, Divinely oriented consciousness, brings us back to the unadulterated state of the Garden of eden, where God placed us before we committed the primordial sin of eating that which God had forbidden. Just as mankind was exiled from the edenic state because of choosing to eat unwisely, so our return to the edenic state depends on rectifying our most basic drive — our need to eat.



Torah of Life – An Integrated Torah-biology TextbookChApTer 08 – Nutrition

Chapter 15

FIGUre 15.1

Feedback Loops

The function of the hypothalamus in the feedback regulation of temperature in the human body.

In tHIS CHaPter

• TheNervousSystem

• TheNerveImpulse

• TheSynapse• AnatomyoftheBrain

• ThePeripheralNervousSystem

The nervous system

1700

Thalamus

Hypothalamus

Increased bodytemperature

Body temperaturedecreases

Thermostat inhypothalamus

activatescooling mechanisms

Thermostat inhypothalamus

activateswarming mechanisms

Internal body temperatureof approximately 37°C





The need to maintain a stable, controlled environment within the body is crucial to the overall functioning of the different organs, and the human body as a whole. homeostasis refers to the ability of the human body to keep internal conditions in balance in the face of constantly fluctuating external environmental conditions.

consider a thermostat, which regulates the temperature of a room. it operates on similar principles as the homeostatic mechanisms of the human body by regulating environmental conditions. The thermostat’s sensor gets triggered to activate the heating system when the temperature drops below a certain set point. similarly, when the temperature in the room rises above this set point, the thermostat’s sensor is triggered again, but this time to turn off the heating system. in this way, the thermostat maintains the temperature of the room within a tight range.

The operation of the thermostat creates a feedback mechanism between three entities— the thermostat, the temperature of the room, and the heating system. The feedback mechanism operates as a negative feedback loop that acts on the principle of feedback inhibition, in which a stimulus initiates a response that opposes the original stimulus. The stimulus, in this case the elevated temperature of the room, initiates an opposite response (turning the heating system off) to the original stimulus (cool room temperature).

The human body is also capable of achieving homeostasis through the mechanism of feedback inhibition (fiGure 15.1). The body’s systems are able to regulate the cellular environment and respond to feedback from these activities by switching the systems on or off, depending on the need. To achieve this, all organ systems must be integrated with one another.

for example, regulating body temperature has a lot in common with the example given above of the thermostat regulating the temperature in a room. in this case, the brain’s hypothalamus monitors the internal temperature of the body’s organs, as well as the temperature of the skin at the body’s surface. The hypothalamus is a small region of the brain that controls various functions in the body, including temperature regulation, food and water intake, the sleep-wake cycle, and endocrine, autonomic and motor functions.

Without homeostasis, people (and living organisms in general) could not survive for long. external changes, often extreme or even violent, would disrupt the equilibrium of the system to the extent that it would collapse and break down.

This is exactly what happened in the primordial form of creation (called Tohu— the World of chaos) that preceded the creation of the world as we know it. it is referred to briefly in the second verse of Genesis: “and the world was without form (Tohu) and equilibrium.” as a result it disintegrated, so that each of its seven “kings” ruled for only a very short period of time and died (Genesis 36:31 ff.). each king represents an era of domination by a single unbalanced emotional attribute. as soon as each attribute assumed kingship, it lost balance (was unable to maintain homeostasis) and collapsed.

1701





our psychological and spiritual makeup parallels our physical makeup. in order to thrive and fulfill our purpose in life, we must maintain psychological and spiritual homeostasis; we must stabilize our spirits (the fluctuations that take place in our soul). We must maintain our emotional highs and lows within reasonable boundaries (just as body temperature should stay around 37°c), lest we become bipolar (“mood swings” between mania and depression) and trigger a nervous breakdown (as was the fate of the primordial kings of the World of chaos).

how do we maintain this homeostasis? by fulfilling the first precept of Jewish Law: “Place God before you always.” The ba’al shem Tov (the founder of the chassidic movement) called this “the law of equanimity.” it is the ability to maintain spiritual equilibrium amidst changes (even drastic changes) in the world around you, and across an enormous range of conflicting emotions. This ability stems from the fact that all life-experiences derive from and reflect one constant cause, “The cause of all causes,” God, the absolutely good creator of the universe.

The great rabbi Levi Yitzchak of berditchev would often sing to God: “above – You! below – You! east – You! West – You! north – You! south – You! if it’s good – You, and if not – also You! and if it’s You, it’s good! You, You, You, all is You!” That is the secret of spiritual homeostasis, even for one that soars up to heaven (to bring God down to earth) and descends to hell (to redeem lost souls).

spiritual homeostasis must be an integral aspect of our lives. The Talmud tells of one extreme example of a lack of spiritual homeostasis. it tells of the four sages who attempted to rectify the primordial sin of adam and eve and entered the “Pardes” (also known as the “orchard,” a metaphor for the mysteries of creation and Godliness that are revealed in higher planes of reality, the “higher worlds” in kabbalah). They were rabbi akiva, ben azai, ben zoma, and elisha acher. ben azai died, ben zoma went insane, and elisha acher became a heretic.

only rabbi akiva entered in peace and came out in peace. only he was able to maintain spiritual homeostasis (a state of inner equilibrium and peace) because he possessed a feedback inhibition control system! his heart began soaring up to heaven to enter the Pardes, gaining energy and spiritual heat (passion and fervor) from moment to moment. he could have expired in ecstasy when he reached the epitome of Divine revelation that his soul was capable of conceiving. but at that exact moment of spiritual danger, his heart told him to return to his earthbound reality (this being the true desire of God). The other three sages lacked this feedback inhibition.

We also note a lack of feedback inhibition in the biblical story of nadav and avihu, the two sons of aaron the high Priest. nadav and avihu died in a fiery run upward to God, not knowing at what moment to return, and not desiring to return.

a story illustrating the same point is also told about rabbi avraham, the son of the magid of mezritch, nicknamed the “Malach” (angel) because of his ecstatic worship. one time he was studying with his close friend, rabbi shneur zalman (the first rebbe of chabad), and he reached such a state of





spiritual ecstasy that he was about to expire. rabbi shneur zalman sensed this and immediately stuck a piece of bagel in his mouth, bringing him out of his ecstatic state and back down into mundane reality.

usually, the body’s core temperature is higher than that of the skin. in response to a drop in core body temperature below 37°c, the hypothalamus releases chemicals that instruct the cells of the body to increase their activities, thereby producing additional heat and raising the core body temperature back to the set point. When the hypothalamus detects this rise in body temperature, it ceases production of the chemicals, thereby preventing a temperature rise beyond the set point. as with the example of the thermostat and heating system, the human body utilizes a negative feedback loop to keep body temperature in balance.

other mechanisms that the body uses to maintain temperature homeostasis include the shivering response in cold weather, and the sweating response in hot weather. When the core body temperature drops below its normal range, the hypothalamus releases chemicals that cause the involuntary contractions of the muscles below the skin’s surface (shivering response). This response produces heat, which raises the body temperature.

similarly, sweating in hot weather is the result of the hypothalamus triggering sweat glands to produce sweat, which, through evaporation at the skin’s surface, helps cool the body down. The return of the body’s core temperature back to the normal range provides feedback inhibition to the hypothalamus to stop the sweating response.

The temperature of the body’s core is the temperature of the heart, which is naturally higher than that of the skin. The zohar states that the heart may be pulsating and alive (generating heat) even when the pulse of the wrist is dead (cold). This was the state of the eighth primordial king of the World of chaos, hadar, who in the Torah (the five books of moses) is said to have reigned but not to have died (as is explicitly stated of the previous seven kings). but in chronicles (written by ezra the scribe) he is said to have died. The zohar explains the discrepancy: moses measured hadar’s heart pulse and in his core he was alive, but ezra measured his wrist pulse and there he was dead.

The ba’al shem Tov continuously trembled (shivered). The airwaves produced by his trembling would even reach a glass of water situated on the other side of the room and the water would begin to quiver as well. anyone who would touch the ba’al shem Tov while he was praying would start shuddering violently.

in the service of God, love raises one’s bodily temperature (a physical phenomenon that can be measured) and fear reduces it (as in the expression “shivering with fear”). The ba’al shem Tov loved God and feared him above our capability to comprehend. he is best known for his love of God, of israel, and of all of God’s creations, but in his Divine service his fear of God exceeded his love, and so he shivered!





The concept of homeostasis applies in a planetary sense as well— in terms of the multi-year cycles of global warming and cooling— and indeed the survival of the planet depends on maintaining homeostasis, just as the health of a person does. moreover, the Torah teaches us that man’s actions on a spiritual plane also affect this delicate earth eco-system, as the verse states:

“all the wild shrubs did not yet exist on the earth, and all the wild plants had not yet sprouted. This was because God had not brought rain on the earth, and there was no man to work the soil” (Genesis 2:5).

The classic commentator rashi explains that there was as yet no “rain on the earth” because “there was no man to work the soil”— there was no one who recognized the goodness of rain until adam came along. realizing that rain is a necessity for the world, adam prayed for rain and when it came down, the vegetation sprouted.

furthermore, the homeostasis of the world depends on our actions and good deeds, and this is one of the interpretations of the mishnah (Sanhedrin 4:5): “a person is obligated to say, ‘The world was created for my sake.’” in other words, the continued existence of the world depends upon our actions.

The macrocosms— the earth, the planets, and the universe, and the microcosms— the human being, the cells, the molecules, and the atoms, are all part of God. in the human being, the soul and the body are united and pulsate together. science has no tools to describe the soul, but a unified Torah-science discourse brings the soul and the body together in a precise and harmonious way.

The SoulThe soul is eternal and a part of God. The soul experiences our body and the physical world around us, and at the same time, experiences God.

The great Torah scholar, maimonides, taught that nothing could be said about the essence of God. We are commanded to believe in his existence (as the creator of the universe) and that he is absolutely one. The ba’al shem Tov made a revolutionary conceptual leap when he taught that because God is one, and the Divine soul is an “actual part of God,” by contemplating the essence of the soul (in its service of God), we in fact gain a glimpse of the essence of God.

The soul is in a continual cycle of “running and returning.” it soars upwards, seeking to become one with its creator, and it comes back down to earth, entrusted with the mission of making a dwelling place for the creator in this world. The heartbeat in the body is the harmonic response to this “running and returning” of the soul, which extends via the bloodstream to the pulse in the wrist.

in the bible, the soul is referred to by five names, each reflecting a different dimension of the Divine character of the human being.

• The nefesh (psyche) resides primarily in the liver.

• The ruach (spirit) resides primarily in the heart.

every night before sleep, we give our tired and worn-out souls back to God. every morning, we receive our soul anew, refreshed and full of energy. Therefore, the first words that we say upon awakening are:

“I thank You, ever living King, for compassionately returning my soul to me; how great is Your faithfulness.”





• The neshamah (the soul proper) resides primarily in the brain.

• The chayah (the living one) resides in the space between the skull and the brain.

• The yechidah hovers outside the body, above the head.

The nefesh connects to the rest of the body through the lymphatic system, the ruach through the circulatory system, the neshamah through the nervous system, the chayah through the respiratory system, and the yechidah through the belief system of the soul.

The nervous SystemThe brain, the spinal cord, and the peripheral nerves make up the nervous system. This system coordinates and controls bodily functions by detecting and responding to internal and external messages. The building blocks of the nervous system are the nerve cells, called neurons, and the supporting cells, called glia. Glial cells play a role in both structural support and in the development and function of the nervous system, and are discussed in more detail below.

There are three stages of information flow in the nervous system: a) sensory input via the five senses (sight, hearing, touch, taste, and smell), and from internal conditions of the organs, such as blood pressure and carbon dioxide levels; b) integration of these stimuli in the brain; c) motor output via the muscles and glands. The part of the nervous system that processes information and signals the responses to these stimuli is called the central nervous system (cns) (fiGure 15.2).

The sensory input via the senses and the motor output via the muscles and glands is the function of the Peripheral nervous system (Pns). both of these functions are discussed in detail later in the chapter.

Information Flux through neuronsneurons transmit tiny electrical signals, called impulses, through the nervous system to convey information the brain sends and receives. The human brain is estimated to contain 1011 (that’s 100 billion) neurons.

neurons are usually classified into three types, based on the direction traveled by the message they carry. sensory neurons carry messages from the sense organs to the spinal cord and the brain. motor neurons carry impulses from the brain and spinal cord to the muscles and glands. interneurons coordinate higher brain functions, mediate simple reflexes, and integrate and connect impulses from the sensory and motor neurons.

although they can come in numerous shapes and sizes, all neurons have the same basic structure (fiGure 15.3). all neurons have a cell body, also called a soma, where most of the metabolic activity takes place. The cell body contains a nucleus and most of the cytoplasm of the cell.

extending out from the cell body are short, branched structures called

FIGUre 15.2

The Central nervous System and the

Peripheral nervous System

The CNS is comprised of the brain and the spinal cord. The PNS connects the CNS to the organs, glands, and limbs.

Brain Spinal Cord

Central Nervous System

Spinal NervesBody Nerves

PeripheralNervous System

Organs





dendrites (from the Greek dendron, meaning “tree”). They receive signals from other neurons and from the environment. also extending out from the cell body is the axon, a much longer extension with a different function— to transmit impulses from the cell body to other cells or neurons.

although they are microscopic in diameter, axons may extend several feet in length. The longest axons in the human body are those of the sciatic nerve, which run from the base of the spine to the big toe of each foot.

neurons may have multiple dendrites but have only one axon. axons may branch many times before terminating. The axon ends in small branching filaments called axon terminals.

bundles of neurons with their dendrites and axons form nerves. some nerves consist of only a few neurons; others comprise hundreds or even thousands of neurons. both axons and dendrites form special contact points called synapses (sing. synapse), where information between nerves is transferred through a series of electrical and chemical changes.

axons are usually enclosed by an insulating membrane known as the myelin sheath, which is produced by specialized glia called oligodendrocytes and schwann cells. oligodendrocytes produce myelin in the cns, and schwann cells produce myelin in the Pns.

The gaps between the myelin sheaths, where the axon is exposed, are called the nodes of ranvier. as an impulse moves along the axon, it jumps from node to node, by a process called saltatory (“jumping,” from the Latin saltare, meaning “to jump”) conduction. This process results in a cascade of depolarizations and action potentials that increase the speed at which the impulse travels along the axon.

transmission of the nerve ImpulsePlease recall that information travels through the nervous system as tiny electrical signals called impulses, similar to the way electricity passes through a wire. however, electric signals within the body are generated electrochemically— by chemical “ion pumps” rather than by a mechanical

FIGUre 15.3

The neuron

All neurons have a cell body with a nucleus and other organelles enclosed in the cytoplasm. The dendrites are extensions of the cell body that receive signals and communicate them to the cell body. The axon is a long extension of the cell body covered with myelin that carries the nerve impulses away from the cell body. Gaps in the myelin expose the axon and facilitate the rapid conduction of the nerve impulse along the axon.

Nucleus

Axon

Cell Body

DendritesAxon Terminals

NodesMyelin Sheath





generator. an ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the molecule a net positive (more protons) or negative (more electrons) electrical charge. We will soon examine how these ion pumps work.

resting Potential

When a neuron is not transmitting an impulse, we say that it is “at rest.” When at rest, the inside of the cell maintains a net negative charge, while the outside of the cell has a net positive charge.

Why is there a difference in electrical charge between the inside and outside of the cell? in part, because the cell membranes are selectively permeable, meaning they allow the passage of some molecules while preventing others from entering or leaving the cell. This causes a difference in the sum of electrical charges inside and outside of the cell. The outside of the cell has an excess of sodium ions (na+), whereas the inside of the cell contains an excess of potassium ions (k+), together with negatively charged protein and nucleic acid molecules. This results in an overall negative electrical charge.

but the primary reason that the cell carries an overall negative charge is because of a process known as active transport. in this process the cell actively “pumps” na+ out of the cell and k+ into the cell via the sodium-potassium pump, which is a protein located in the plasma membrane (fiGure 15.4).

one of the important functions of the sodium-potassium pump is to help maintain the resting potential. When the neuron is inactive and polarized (i.e., it carries an overall negative charge relative to the charge outside of the cell), it is at its resting potential, and this is the way it remains until the neuron responds to a stimulus.

of course, this does not mean that the cell is inactive at the resting potential stage; among other things, it is constantly producing adenosine triphosphate (aTP), which provides the chemical energy needed for active transport (fiGure 8.2 from chapter 8). aTP contains the four basic elements upon which all organic life depends— carbon (c), hydrogen (h), nitrogen (n), and oxygen (o). its chemical formula is c10h16n5o13P3.

Inside of Cell

Outside of Cell

K+

K+

K+K+

K+

K+

K+

K+ K+

K+

K+

Na+

Na+

Na+

Na+

Na+Na+

Na+

Na+

Na+

ATP

Cell Membrane

Sodium-potassiumPump

FIGUre 15.4

The Sodium — Potassium Pump

A protein pump in the neuron cell membrane pumps sodium out of the cell and potassium into the cell using ATP as the energy source.

H

Adenine

Ribose

Phosphate Groups

C C

CN

C H

N

H HC

OH

H

C

OH

H

O

C

H2C O P

O

O P

O

O P

O

O O O

O H

N

N

C

NH2

H H H

ATP Adenosine triphosphate C10H16N5O13P3

C

Energy Rich Bond

FIGUre 8.2

ATP, Adenosine triphosphate

ATP is a chemical compound consisting of the nucleotide adenine, the five-carbon sugar, ribose, and three phosphate groups. The breaking of the chemical bond between the second and third phosphate group releases a relatively large amount of energy that is used by the cell to fuel many energy-requiring processes.





rest is thus not a passive state but a state in which the neuron actively orients itself with respect to positive and negative electric charges along its membrane. similarly, shabbat as the day of rest is not in essence a passive state, but one in which a person elevates the active states of the past week, and orients the coming week in a positive direction, yet in a “restful,” non-active manner.

in kabbalah, a positive charge (more protons than electrons) is called feminine energy, whereas a negative charge (more electrons than protons) is called masculine energy. in the neuron, the male energy is inside the cell and the female energy is outside. on the spiritual plane, masculine energy is love, while feminine energy is awe.

The myelin sheaths that cover the neuron’s axon are membranes rich in essential fatty acids, which in the spiritual plane derive from the power of compassion (tiferet). compassion is what defines and regulates the male-female interactions, in our case the inside and the outside of a neuron cell at rest.

God created the world with the attribute of severe justice and instructed humanity to keep the Torah and to fulfill its precepts in order to live. initially, he didn’t allow for a second chance. but the almighty saw that humans are prone to fall. and so he began ruling the world with the attribute of compassion and brought teshuvah (repentance and return) to humanity. complete repentance and return bring redemption to the world.

in modern hebrew, the mysterious word chashmal means “electricity.” The ba’al shem Tov elucidated the inner meaning of the word chashmal as a simultaneous, paradoxical state of silence (chash) and speech (mal). in other words, chashmal means a simultaneous state of concealment and revelation. The word chashmal appears only in one context in the bible, in ezekiel’s vision of the Divine chariot (considered the deepest mystery of the Torah). Chash, silence, is the inner silence required to face and know reality as it is. Mal, speech, is the sweetening, unifying process, which, after recognizing essential distinctions between things, brings different aspects of reality together.

aTP provides the energy for the sodium-potassium pump. aTP is the molecule that acts as the “currency” for energy transfer throughout the body. The formula of aTP (c10h16n5o13P3) includes the four elements (hydrogen, carbon, nitrogen, and oxygen) that represent the four basic elements of creation in the classical understanding of the physical world.

h, hydrogen, the main component of water, represents the liquid state of matter and the sefirah of chesed, loving-kindness. c, carbon, represents fire, the state of active combustion, and the sefirah of gevurah, might. n, nitrogen, represents earth, the solid state of matter, and the sefirah of malchut, kingdom. o, oxygen, represents air, the gaseous state of matter, and the sefirah of tiferet, beauty. The atomic numbers of these four elements are 1, 6, 7, and 8, which total 22 (meaning that they include 22 protons and 22 electrons), alluding to the 22 letters of the hebrew alphabet, the building blocks of creation according to kabbalah.





The traveling Impulse

When a neuron receives a large enough stimulus via its dendrites, the stimulus causes a nerve impulse to travel down the axon away from the cell body towards the axon terminals. because the nerve impulse is a very small electric signal, it causes a reversal of the electrical charges between the interior and exterior of the cell as it travels down the axon. how does this happen?

similar to other cell types, the cell membrane of a neuron contains numerous types of ion channels, which are protein structures embedded in the membrane that can allow passage of specific types of ions.

some ion channels are chemically gated. a chemically gated channel is one that is activated by a specific ion (e.g., a potassium ion). other channels are voltage-gated (they are activated by changes in electrical charge). The sodium-potassium pump mentioned earlier is voltage-gated, which means that both sodium and potassium channels are opened by changes in the electrical charge of the membrane.

This is how it works: axons transmit electrical impulses called action potentials, which are the result of a rapid rise and then fall in the electrical potential of the axon’s membrane (fiGure 15.5). an action potential begins at the cell body when sodium channel gates open to allow a flow of positively charged na+ ions to rush into the cell, establishing a new equilibrium in a matter of a millisecond.

The voltage of the inner membrane changes from a negative charge of about -70 mv to a positive charge of approximately +30 mv. This switch in membrane potential triggers the opening of k+ channels, causing k+ ions to rush out of the cell at almost the same speed as the inward flow of na+ ions.

as a result, the charge of the inner membrane returns to its original negative resting potential state. The neuron is once again negatively charged inside the cell membrane and positively charged outside. The action potential of most neurons is of very short duration, only about one to two milliseconds. note that each channel responds independently and sequentially: na+ channels open before k+ channels.

a nerve impulse is self-propagating. This means that an impulse (an action potential) automatically triggers the neighboring membrane area into producing an action potential, thus moving the impulse along the axon.

one amazing feature of neurons is that after a very short period of rest known as the refractory period, the membrane restores its ability to respond to and propagate the next action potential. The refractory period results from the fact that the na+ channels enter a brief state of inactivation after they close back up, following an action potential.

Insulation of axons

as mentioned previously, the myelin sheath is organized in such a way that it leaves gaps at regular intervals along the axon (fiGure 15.3). The na+ and k+ channels are concentrated in the exposed areas of the axon (unmyelinated

Time (msec)

-1000 3 6

-50Threshold

RestingPotential

Action Potential

0

+50

Stronger Depolarizing Stimulus

Mem

bra

ne P

oten

tial (

mV

)

FIGUre 15.5

The Action Potential

A strong depolarizing stimulus reaches the threshold and triggers an action potential.





areas) in a way that propagates the action potential as it skips along the axon. This speeds up transmission of the action potential tremendously, to a rate as fast as 100 meters per second.

The action Potential

an action potential only occurs when a stimulus is powerful enough to cause the neuron to transmit an impulse (fiGure 15.5). The minimum stimulus required to cause enough sodium ions to rush into the cell to sufficiently depolarize the membrane is called the threshold level. if the stimulus is not powerful enough to open the sodium gates in the membrane, then no impulse is produced. This follows an all-or-nothing principle, meaning that an action potential either occurs in response to a sufficiently large stimulus (or a summation of smaller stimuli), or it does not, if the stimulus is not strong enough to cause the sodium channels to open.

action potentials always have the same intensity and are never reduced by the length of the axon. however, a stronger stimulus will cause more action potentials to travel along the axon. some very efficient axons can propagate action potentials at a frequency of up to 1,000 times per second.

The shabbat is unique because it does not involve impulsive activity. before the onset of shabbat one is instructed to enter a state of consciousness defined by the sages as “all your work is completed.” and so, on shabbat, one avoids the psychologically negative state of impulsiveness.

a threshold is achieved by reaching a critical mass. it takes critical mass to begin a chain reaction (a snowball effect) that will bring about a significant change in the state of any system. This is true from the microscopic world to the macroscopic world, from particle physics to astrophysics, from biology to psychology to politics.

revolutions take place when the populace reaches a critical mass of opposition to the existing regime. it all depends on the stimulus. similarly in our spiritual endeavors, our teachers attempt to stimulate our curiosity by offering interesting insights and observations, in the hope that we will go beyond the threshold level, and become fully involved and productive members of our communities.

in the rest state, the negatively charged state inside the cell is masculine, and the positively charged state outside the cell is feminine. These attributes are standard, like those that allow us to recognize a baby boy from a baby girl. The masculine and feminine states are separated by the cell membrane. When a nerve impulse is triggered, it psychologically translates into a burst of feminine energy, which is associated with an action potential.

The Synapseas we explained earlier, the axon ends in an axon terminal (fiGure 15.5). When an impulse reaches the neuron’s axon terminal it may be passed on to another neuron, muscle cell, or gland cell. The small junction across which a nerve impulse may pass is called a synapse.



Neuron

Axon

AxonTerminal

NeurotransmitterMolecules

Axon

Ele

ctric

al Impulses

ReceptorSynapticCleft

Dendrite &Neighboring Cell



a synaptic cleft (fiGure 15.6) separates an axon or dendrite terminal from an adjacent neuron or other cell. The transmitting neuron is often called the presynaptic neuron because it comes before (pre-) the synapse, while the receiving cell is called the postsynaptic cell because it comes after (post-) the synapse.

There are two types of synapses, both of which are found in humans: chemical synapses (fiGure 15.6) and electrical synapses. in chemical synapses, the impulse reaches the axon terminal of the transmitting neuron and causes vesicles (small chemical storage sacs) in the axon to release a chemical known as a neurotransmitter into the synaptic cleft. These neurotransmitters bind to receptors on the membrane of the receiving cell. This stimulates the membrane of the receiving cell, causing na+ ions to flow quickly into the receiving cell, reversing the resting potential of that cell.

if the stimulus exceeds the receiving cell’s threshold, an impulse begins in the receiving cell and moves down the receiving cell’s axon as described previously. once the neurotransmitters are no longer necessary, they are released by the receptors and are then recycled by the axon terminal or are broken down by special enzymes. The vast majority of synapses in humans are of this type.

in electrical synapses, the pre-synaptic and postsynaptic cell membranes are connected by pore-like channels that conduct the impulse electrically. They are quite rare in humans, but some are found in the heart, the eye, and the brain. The synaptic gap in electrical synapses is far narrower than in chemical synapses.

in kabbalistic terminology, the synaptic cleft represents the state of non-being (“nothingness”) between two states of being. if each neuron is considered a “something,” then the synaptic cleft between them is the “nothing” between two “somethings.” it is the “nothing” that allows for the transmission of energy (in our case, impulse) from one “something” to another (from neuron to neuron, or from neuron to muscle tissue).

The ultimate sense of serenity experienced by the Divine soul is a sense of true “nothingness.” The animal soul of the human being experiences pleasure as “something,” while the Divine soul experiences pleasure as “nothingness.” The pleasure of experiencing the Divine source of all reality, the Divine “nothing” from which all “something” has been created, makes us feel truly humble and reduces our own sense of self to “nothing.”

The neurotransmitters are capable of traversing the abyss of “nothingness” between “something” and “something,” and convey the desired message from one state of being to the other. They are “messenger” particles, force carriers.

after binding to their receptors in the receiving, second “something,” they are released from the cell surface (they do not enter into the second cell) and are either broken down by enzymes or taken up and recycled by the axon terminal of the first “something.”

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FIGUre 15.6

The Chemical Synapse

Neurons can signal each other through chemical synapses. An electrical impulse traveling along an axon reaches a synapse, the area at which two neurons contact each other. The gap between the two neurons is called the synaptic cleft. When an impulse reaches the axon terminal of a transmitting neuron, neurotransmitter vesicles are released and the neurotransmitter binds a receptor in the other neuron.





Skull

Dura Mater

ArachnoidPia Mater

Occipital Lobe

Parietal Lobe

Reading Comprehension Area

Sensory Speech

Cerebellum

Medulla Oblongata

Pons

Motor Speech

Temporal Lobe

Frontal Lobe

The Central and Peripheral nervous Systemsas mentioned earlier in the chapter, there are two primary networks within the nervous system: the central nervous system (cns) and the Peripheral nervous system (Pns). The cns processes and analyzes information and signals a response (fiGure 15.2). The Pns receives sensory input and connects the cns to the organs, glands, and limbs.

The Central nervous System

The brain and the spinal cord comprise the cns (fiGure 15.2). The skull encloses the brain and protects it from injury. similarly, the vertebrae of the spinal column protect the spinal cord from harm. The brain and the spinal cord are further protected by three layers of meninges (sing. meninx) which are membranes that envelop the cns (fiGure 15.7a). The three layers are the dura mater, arachnoid mater, and pia mater. inflammation of the meninges is called meningitis, a dangerous and potentially fatal disease.

cerebrospinal fluid flows around the brain and spinal cord, and within the brain cavities. it delivers nutrients to the brain and spinal cord and detoxifies the environment of the cns by disposing of waste products. in addition, the cerebrospinal fluid provides cushioning support to both the brain and the spinal cord, and protects the brain from trauma within the skull.

The relationship of the central nervous system (cns) and the Peripheral nervous system (Pns) is like that of a king and a servant. The servant receives information from the outside world and conveys the information to the king, who then processes and analyzes it, makes decisions, and commands his subjects. The commands are relayed to the subjects by the servant.

in democratic systems typical of our times, power is shared and allocated to different segments of society. The cns could not function following such democratic principles. societies adopt democratic systems when they feel the need to allow for different, often conflicting values and goals to co-exist. in

FIGUre 15.7a

The three layers of meninges that

envelop the central nervous system.

FIGUreS 15.7b and c

The two hemispheres and four lobes of the human brain.

a b c

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Right HemisphereFrontal Lobe

Parietal Lobe

Occipital Lobe

Longitudinal Fissure

LeftHemisphere





contrast, the regimes of righteous Jewish kings, such as David and solomon, portray monarchy in a totally different way than the way it is usually thought of today. True Jewish monarchy serves to perfect society by promoting justice and loving-kindness. The righteous kings of israel took the Jewish people (and the world) in directions that they could not go on their own. Likewise, in the cns, the brain has the capacity to provide the functional wisdom to lead the body and fulfill its purpose.

another parallel between the Torah and the nervous system is related to the typography of the Torah. There are four typographical levels in the Torah text: the letters, the crowns inscribed on the top of the letters, the vowels (without which the letters cannot unite to form audible words), and the ta’amim, the cantillation marks (in Yiddish, the trop), literally the “tastes” (or “reasons”) that define the sentence structure and serve as musical notation for chanting the verses of the text.

The letters and crowns atop the letters in the Torah scroll are revealed to the eye and correspond to the revealed levels of Torah interpretation, peshat and remez. (see illustration on the right.) The vowels and the ta’amim are hidden and correspond to the concealed levels of Torah interpretation, derush and sod.

These four typographical levels correspond to the four levels of consciousness represented by the four letters of God’s essential name, Havayah. The first letter of the name, the yud, represents the highest level of consciousness, which is Divine consciousness. This is the level of the ta’amim in the Torah text, the music of the Torah. The ta’amim are cantillation marks that indicate both the melody to be used for each word, and the overall cadence of the verse. so the ta’amim are both a musical shorthand and a guideline to the grammatical structure of the text.

The individual ta’amim (which are not individual notes but complete bars of notes) are divided into two categories, the kings and the servants, similar to the way we picture the central nervous system in relation to the Peripheral nervous system. The major divisions of the sentence structure of the verses of the Torah are determined by the kings, but the servants add (bring) information (musical eloquence) to the king so that his statements (intonations) carry full weight.

The comparison of the nervous system to the highest level of the Torah, the ta’amim, is most significant. in the Torah we find the idiom ta’am veda’at (taste/reason and knowledge). from this we learn that the ta’amim relate in particular to the sefirah of knowledge (da’at), the seat of the nervous system among the physiological systems of the human body.

Thus, we could say that singing the song of the Torah (the Torah in its entirety is God’s song to man) brings about healing to the nerves. (sing the Torah and you’ll never need to see a neurologist or a psychiatrist!)

kabbalah explains that before receiving a new, higher level of consciousness (a revelation of a higher level of one’s soul), one must enter a state called “second (spiritual) pregnancy.” one must return to the womb and be born anew (as is the mashiach every instant). all of this is a function of the brain in its womb, the skull.

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Above is the first verse in the Book of Exodus (chapter 1, verse 1), describing the descent of Jacob and his household to Egypt. In this presentation, the words are written with the crowns on top of the letters (only some letters have crowns), with the vowel signs (in red), the cantillation marks that are kings (in blue), and cantillation marks that are servants (in gray).

In a Torah scroll, the text would appear with only the letters and their crowns, as depicted in the image above, right.

Among the cantillation marks considered kings, there is an inner hierarchy, with two of them, the etnachta and the sof pasuk (see illustration on top), designated as emperors—the highest level.

Since Hebrew is written from right to left, all the cantillation marks found to the right of a king (all the way to the previous king) are considered part of its entourage.

crowns adorning letters

The etnachta mark

The sof pasuk mark





anatomy of the Brain

The brain in an average adult weighs around three pounds (1.3-1.4 kg). although it is only around 2% of the body’s weight, it uses 20% of the oxygen supply and 20% of the blood supply. The brain is divided into three distinct sections: the cerebrum, the cerebellum, and the brain stem, made up of the pons and the medulla oblongata (fiGure 15.8).

The cerebrum is the largest and uppermost part of the brain. it controls voluntary actions, speech, senses, intelligence, thought, and memory. a deep groove in the cerebrum, known as the longitudinal fissure, runs from the back of the head to the front, and divides it into two hemispheres, the right and left hemispheres (fiGure 15.7b).

each hemisphere controls the opposite side of the body. Thus, the left side receives sensory information from and controls the movements of the right side of the body, while the right side of the brain receives information from and controls the movements of the left side of the body.

The two hemispheres are connected at their base by a band of tissue called the corpus callosum that has 200-250 million neurons, and allows each side of the brain to communicate with the other (fiGure 15.8).

in addition, it appears that the right hemisphere is linked to creative and artistic aptitude, whereas the left hemisphere is linked to mathematical and analytical aptitude.

each hemisphere is subdivided into lobes, which are named for the section of the skull covering them (fiGure 15.7c). The frontal lobes are associated with intelligence, personality, speech, and motor development. The temporal lobes are responsible for memory, language, hearing, and speech functions. The parietal lobes are involved with sensation or touch. The occipital lobes are the primary centers of vision.

much of what we know about the function of individual sections of the brain comes from correlating brain injuries with various dysfunctions in those who have suffered brain damage or illness. however, the correspondence may be imprecise.

in addition to the right and left divisions of the cerebrum, there is also an outer and inner division of each of the hemispheres. The outer layer is called the cerebral cortex (fiGure 15.8) and is gray in color due to the unmyelinated axons that make up this area.

The inner layer is whitish in color, due to the presence of myelin sheaths covering the axons in this region.

The cerebral cortex is only 2-4 mm (0.08-0.16 in) thick, but convolutions and crevices (called gyri and sulci, respectively) on the surface of each hemisphere greatly increase the available area for information processing and storage.

The right and left hemispheres of the cerebrum correspond to wisdom (chochmah) and understanding (binah), the father and mother principles, respectively. The inner experience that accompanies the flash of wisdom

Pons(Brain Stem)

Corpus Callosum

Cerebrum

Cerebral Cortex:Outer Layer ofthe Cerebrum

Cerebellum

Medulla Oblongata(Brain Stem)

FIGUre 15.8

The cerebrum and the cerebellum

Brain Stem

Corpus CallosumCerebellum

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generated by a new insight is a sense of selflessness. The inner experience that accompanies the understanding of an idea in full is joy, the joy of conception.

We have a sense of success when we integrate the flash of wisdom with a sense of imminent motherhood as we give birth to a full-fledged emotion in the heart. The sense of selflessness emanates from the right hemisphere of the cerebrum, and the sense of joy from the left. These two feelings should always be present and balanced in our consciousness. The band of tissue that connects the two sides of the cerebrum is the interface between wisdom and understanding.

Primarily “right hemisphere” people are more intuitive and fast to act on what first comes to mind. Primarily “left hemisphere” people are more rational and deliberate, and they tend to act on second thought. The functions of the four lobes of the cerebrum can be summed up as: frontal lobe – intelligence, occipital lobe – seeing, Temporal lobe – hearing, and Parietal lobe – touch.

The frontal lobe is relatively active (it analyzes, makes decisions, and controls speech), while the other three are receptive (they are sensors and interpreters of sensations). The frontal lobe includes all three faculties of the intellect – wisdom, understanding, and knowledge, which relate to seeing, hearing, and touch, respectively.

Gray (which includes all shades of gray) is the color associated with the attribute of knowledge (da’at), the sefirah which corresponds in particular to the nervous system. White is the color of the crown (keter), the unconscious origin of knowledge, the root of the nervous system. so we have white, crown, and grey, knowledge. The myelin sheaths that give the white matter its color are produced by the essential fatty acids as mentioned above, corresponding in the soul to the emotive attribute of compassion (tiferet).

The more grooves found in the tissue, the more room to hold information and gain new insight and comprehension. in hebrew, one of the synonyms of “to think” or “to contemplate” is the same as “to plow.” a deep thinker plows new grooves in his brain, thus expanding his cognitive power. he “seeds” every “furrow” of his mind with insight and “reaps” comprehension.

The cerebral cortex is responsible for information processing in general, including thinking, perceiving, producing and understanding language, memory, social skills, problem-solving, and advanced motor functions.

The cerebellum (Latin for “little brain”) is considerably smaller than the cerebrum, and is located below the cerebrum at the back of the head at the base of the skull, above the brain stem (fiGure 15.8). it is involved in the coordination of voluntary motor movement, balance, and equilibrium. in striking contrast to the cerebrum, the outer surface of the cerebellum is covered with narrowly spaced parallel grooves, like a tightly folded accordion.

The brain stem, a structure continuous with the spinal cord, connects the brain and the spinal cord to each another. it is located below the cerebellum and consists of the midbrain, the medulla oblongata, and the pons.

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The brain stem (fiGure 15.8) controls responses to sight, eye movements, pupil dilation, body movement, and hearing. it is also involved in control of the autonomic functions of the body, such as heart rate, blood pressure, and breathing. The brain stem also relays nerve signals between the brain and the spinal cord, and coordinates body movements.

The brain stem connects the brain to the spinal cord, thereby connecting the brain to the body. on the spiritual plane, this is exactly the place in the Jewish psyche that amalek, the archenemy of israel, opposes, trying to injure the brain stem and make it dysfunctional, or disconnected from the rest of the body. This is also hinted to in his name, which can be divided into two— Am and Malek— the nation (am) which decapitates (called melika in hebrew). he is out to prevent the mind from ruling the heart and the body, not only on the conscious plane but primarily on the subconscious, involuntary plane.

as the ba’al shem Tov taught, both amalek and “doubt” have the same numerical value of 240. he is actually considered to be a reincarnation of the primordial snake who seduced eve to eat from the forbidden fruit. he poisons the mind with skepticism, which results in psychological impotency and inability to properly control the body functions. he is thus responsible for such conditions as high blood pressure, asthma, etc. We are commanded to annihilate him, may it be soon!

The Thalamus and the Hypothalamus

The thalamus (from a Greek word meaning “room” or “chamber”) (fiGure 15.9) receives signals from the sensory receptors throughout the body. some of its functions are to relay sensations, spatial sense, and motor signals to the cerebral cortex for further processing. Like the cerebrum, it has two lobes, right and left, each of which is situated near the center of the brain, beneath each cerebral hemisphere, on top of the brain stem between the cerebral cortex and the midbrain.

The hypothalamus (fiGure 15.9) produces hormones that control body temperature, hunger, thirst, mood, and sleep. These hormones also act on numerous glands, such as the pituitary gland, to coordinate the nervous and endocrine systems. The pituitary is only about the size of a pearl and is located below the thalamus, just above the brain stem (fiGure 15.8).

The Spinal CordThe spinal cord extends through the hollow vertebrae of the spinal column for most of its length (fiGure 15.2). it consists of millions of nerve fibers, which transmit sensory signals from the body to the brain, and motor signals from the brain to the body. it is about the diameter of a human finger.

Thirty-one pairs of spinal nerves branch out from the spinal cord connecting the brain and all parts of the body. The nerves that exit the spinal cord in the upper section (the neck) control breathing and the movement of the arms. The nerves that exit the spinal cord in the mid and lower section of the back control the trunk and legs, as well as the bladder, bowel, and reproductive organs.

Thalamus

Hypothalamus

Frontal Lobe

FIGUre 15.9

The Thalamus and the Hypothalamus

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certain reflexes are processed locally in the spinal cord, before reaching the brain. This automatic, fast response of a reflex to a particular stimulus is crucial in avoiding dangerous situations. for example, the automatic response to the touching of an extremely hot surface is to pull your hand away. This response relies on a reflex pathway in the spinal cord, and does not require stopping to think about how to respond (see below).

The Peripheral nervous SystemThe Peripheral nervous system (Pns) includes the whole nervous system, except for the brain and spinal cord. The nerves in the peripheral nervous system connect the cns to sensory organs (such as the ears and nose), muscles, blood vessels, glands, and other organs of the body. The peripheral nerves include the 12 cranial nerves that pass through small openings in the skull, the spinal nerves and roots, the ganglia (collections of nerve cell bodies), and the autonomic nerves (fiGures 15.2 anD 15.10). The Pns is made up of sensory neurons and motor neurons, depending on the direction that the impulses travel.

sensory neurons relay nerve impulses from the sense organs toward the cns, while motor neurons relay nerve impulses from the cns to the muscles and glands. motor neurons are further subdivided by function into the somatic nervous system and the autonomic nervous system.

The somatic nervous system is associated with activities that are under a person’s conscious control, such as the movement of parts of the body via the skeletal muscles. for this reason, it is also called the voluntary nervous system because its responses can be controlled voluntarily. reflex reactions— involuntary reactions to external stimuli, such as blinking, sneezing, or yanking your hand away from a hot stove— are an exception to the overall voluntary character of the somatic nervous system.

FIGUre 15.10

The Sympathetic and Parasympathetic

divisions of the Autonomic nervous

System. The two systems innervate the same organs but have opposite effects.

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Constricts Pupil

InhibitsHeart Rate

ConstrictsBronchi

StimulatesStomach Mobility

StimulatesIntestinalMobility

Spinal Cord

Brain

Dilates Pupil

Sympathetic Division Parasympathetic Division

AcceleratesHeart Rate

DilatesBronchi

Inhibits Stomach Mobility

InhibitsIntestinalMobility





as explained above, the sensory division of the peripheral nervous system is “chash” (silence) and the motor division is “mal” (speech). The 12 cranial nerves control the sense of smell, vision and eye movement, chewing, and swallowing, the muscles of the tongue, movement, the entire parasympathetic nervous system, hearing and balance, and taste. We can now understand why kabbalah talks about 12 “senses” rather than only the 5 traditional senses of sight, hearing, taste, touch, and smell. included in the 12 “senses” are the “senses” of speech, concentration (or focus or thought), walking, action, sleep, anger, eating, and laughter.

The ba’al shem Tov was in keen control of his somatic nervous system. he would never move a finger without a clear purpose. The slightest physical movement of his body had a spiritual intention (or “unification,” a meditation, that needn’t take more than a split second, to unify the creator and his creation, to unify the infinite and the finite). he was not self-conscious but Divine-conscious, for he was conscious of the fact that we are no more than an “actual part of God above.” and so it is said of rabbi elimelech of Lizhensk, a disciple of the disciple of the ba’al shem Tov, that angels would run to observe him raising or lowering his small finger!

muscles move involuntarily via nerves that connect directly to the spinal cord. This is known as a reflex arc (fiGure 15.11), which loops from sensory receptors (e.g., in the hand touching a hot stove) via sensory neurons connected to the spinal cord, and back via motor neurons to muscles in the arm. in this way, reflexes occur quickly through the local activation of spinal motor neurons, without having to route signals through the brain. however, the brain still receives sensory information during the reflex action.

The autonomic nervous system, also known as the involuntary nervous system, comprises the automatic functions of the body that are not under conscious control, such as the regulation of glands, the heart and other internal organs, and the muscles lining the walls of blood vessels.

The autonomic nervous system can further be divided into the sympathetic and parasympathetic systems (fiGure 15.10). The majority of organs controlled by the autonomic nervous system are connected to both sympathetic and parasympathetic neurons, where each system has the opposite effect on the organ.

The sympathetic system is responsible for speeding up the heart rate, dilating pupils, raising blood pressure, and inhibiting digestion. The sympathetic system is also involved in the so-called “flight or fight” response. This is a response to potential danger that results in accelerated heart rate and an increase in metabolic rate. The parasympathetic system acts in the opposite way by slowing heart rate, contracting pupils, and enhancing digestion. This is sometimes called the “rest and digest” response.

The two legs, right and left, represent the two powers to accelerate or to decelerate, to speed up or to slow down. heartbeat is increased by the sympathetic nervous system (the sefirah of victory, symbolically the right leg) and decreased by the parasympathetic nervous system (the sefirah of

FIGUre 15.11

A Reflex Arc

A stimulus (flame) causes sensory receptors in the skin to generate nerve impulses that travel in sensory neurons to the spinal cord. Interneurons integrate stimuli from sensory neurons and relay signals to motor neurons. The motor neurons convey nerve impulses to the finger muscle, which cause the finger to move away from the flame.

Spinal Cord

InterneuronNeuronto Brain

Flame

Muscle

MotorNeuron

Receptor

SensoryNeuron

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acknowledgment, the left leg). relative to one another, these two systems are male and female, as it says in the zohar: “he (male energy, speeding up) is in victory and she (female energy, slowing down) is in acknowledgment.”

The ba’al shem Tov coined an idiom to describe this ideal “marriage” in the soul: “deliberate agility,” fast (really fast) but slowly (deliberately). These two systems which function together (as a happily married couple) are normally unconscious, but some great sages, like the ba’al shem Tov and the Lubavitcher rebbe, were fully conscious of their autonomic activities and in conscious control of their heartbeat and other body functions. They are the two “legs” within the sefirah of knowledge, which in general corresponds to the nervous system in the human body.

The autonomic nervous system also includes the enteric system that directly controls the gastrointestinal system in vertebrates. it consists of networks of neurons in the digestive tract, pancreas, and gallbladder. These neurons control the secretions emitted by these glands as well as activity in the muscles that produce peristalsis, the organized muscle contractions that occur throughout the digestive tract.



“The goal of the Torah is to unite, and in our generation, our goal is the unification

of Torah and science.”

PlanneD tItle ProjeCtS

Torah anD bioLoGY

Torah anD PhYsics

Torah anD chemisTrY

Torah anD The earTh sciences

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