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Neuroscience and BehaviorNeuroscience and BehaviorChapter 2Chapter 2
What’s In This Chapter?What’s In This Chapter?
• What does biology have to do with our behavior?
• What’s in a brain?????• How does the brain tell the body what to
do?• How does the body let the brain know
what it’s doing?• Can your brain do things without the
body?• Can your body do things without the brain
knowing it?
The BrainThe Brain
Lesion tissue
destruction a brain
lesion is a naturally or experimentally caused
Phineas GagePhineas Gagepage 81
How we Investigate the How we Investigate the BrainBrain
an amplified recording of the waves of electrical activity that sweep across the brain’s surface
these waves are measured by electrodes placed on the scalp
Electroencephalogram (EEG)
CT (computed tomography) Scan a series of x-ray
photographs taken from different angles and combined by computer into a composite representation of a slice through the body; also called CAT scan
Sample image: Perfusion CT in a patient with stroke demonstrates the part of the brain with severely decreased blood flow (arrows).
What are some common What are some common uses of the procedure?uses of the procedure?
• Detection of bleeding, brain damage and skull fractures in patients with head injuries.
• Detects a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke.
• Detection of most brain tumors. • Planning radiation therapy for cancer of
the brain or other tissues. • Guiding the passage of a needle used to
obtain a tissue sample (biopsy) from the brain.
PET ScanPET Scan
PET (positron emission tomography) Scan a visual display of brain activity that detects where a
radioactive form of glucose goes while the brain performs a given task
PET Scan ProcessPET Scan Process
• observe blood flow or metabolism in any part of the brain.
• subject is injected with small quantity of radioactive glucose
• Brain cells use glucose as fuel
• shows levels of activity as a color-coded brain map
• red indicates more active brain areas,
• Blue/green: less active areas.
• gray outer surface is MRI picture of the surface of the brain inner colored structure is cingulate gyrus, part of the brain's emotional system
MRI ScanMRI ScanMRI (magnetic resonance imaging)
technique uses magnetic fields and radio waves
produces computer-generated images distinguish among different types of soft
tissue allows us to see structures within the brain A brief pulse of radio waves disorients the brain’s atoms momentarily, when the atoms return to their normal spin, they release detectable signals.
Healthy brain (left) schizophrenic brain (right)
enlarged fluid filled brain region
• All hot peppers contain capsaicinoids• causes eyes to water, nose to run,
induces perspiration. • no flavor or odor• act directly on the pain receptors in
the mouth and throat. • The primary capsaicinoid, capsaicin,
so hot that a single drop diluted in 100,000 drops of water will produce a blistering of the tongue.
EXAMPLE OF A EXAMPLE OF A COMBINED COMBINED
PET AND MRI SCANPET AND MRI SCAN
Examples of PET and MRI techniques Examples of PET and MRI techniques
Thalamus Cortex
•These 2 images show subjects who received a painful injection of the chemical capsaicin into the upper arm. show increased blood flow (the PET scan shows the thalamus and primary somatosensory cortex after the injection. The gray areas of the images (the MRI) Using this method can identify the areas of the brain that are active during specific conditions.
•could be used to study just about any other cognitive function.
Brain StructuresBrain Structures
• The brain has three main parts: the forebrain, midbrain, and hindbrain.
• The forebrain: cerebrum, thalamus, hypothalamus
• The brainstem: midbrain, pons, and medulla are referred to together as the brainstem
• The hindbrain: cerebellum, pons and medulla.
Lower-Level Brain Lower-Level Brain StructuresStructures
Brainstem the oldest part central core of the brain beginning where the spinal cord swells as
it enters the skull responsible for automatic survival
functions
Medulla [muh-DUL-uh] base of the brainstem controls heartbeat and breathing
The BrainThe Brain
Brain stemBrain stem• "brain stem" is the
part of your brain that was first to evolve in primitive human beings.
• called a "reptilian brain" since it resembles almost the whole brain of a reptile.
• source of all your instincts and feelings!
• links your brain to your "spinal cord.“
• It is where all the incoming and outgoing "messages" come together and cross over.
Controls sleeping, waking, and dreaming
Reticular Formation (the panty hose) a nerve network inside the brainstem
that plays an important role in controlling arousal
Severe damage can induce a coma
Thalamus [THAL-uh-muss] (411 operator) the brain’s sensory switchboard, located
on top of the brainstem; communication passes through
it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Cerebellum [sehr-uh-Cerebellum [sehr-uh-BELL-um] BELL-um]
“Sarah the Southern Belle”
the “little brain” attached to the rear of the brainstem
it helps coordinate voluntary movement and balance
Important in walking, balance, or shaking hands
The Limbic SystemThe Limbic System
Limbic System: a doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres emotions such as fear and
aggression basic drives such food and sex includes the hippocampus,
amygdala, and hypothalamus.
Amygdala [ah-MIG-dah-la] two almond-shaped neural clusters
that are components of the limbic system and are linked to emotion (aggression/rage and fear)
Hypothalamus: neural structure lying
below (hypo) the thalamus; directs several maintenance activities eating drinking body temperature
helps govern the endocrine system via the pituitary gland
is linked to emotion “pleasure center” or
“reward center”
The Limbic SystemThe Limbic System
Electrode implanted in reward center
So reinforcing that the mouse pressed the pedal up to 7000x in one hour
The Cerebral CortexThe Cerebral Cortex
Cerebral Cortex the intricate fabric of
interconnected neural cells that covers the cerebral hemispheres
the body’s ultimate control and information processing center
Glial Cells- glue cells cells in the nervous system that
support, nourish, and protect neurons
Cerebral Cortex: Basic Cerebral Cortex: Basic SubdivisionsSubdivisions
page 78
Structure of the Structure of the Cerebral CortexCerebral Cortex
Frontal Lobes “behind your forehead”
involved in speaking and muscle movements and in making plans (initiative) and judgments (morality)
Parietal Lobes “top and rear”
include the sensory cortexOccipital Lobes “back of head”
include the visual areas, which receive visual information from the opposite visual field
Temporal Lobes “above the ears”
include the auditory areas
Function of the Function of the Cerebral CortexCerebral Cortex
Motor Cortex area at the rear of the frontal lobes
that controls voluntary movements
Sensory Cortex area at the front of the parietal
lobes that registers and processes body sensations
The Cerebral CortexThe Cerebral Cortexpage 79
The Cerebral CortexThe Cerebral Cortex
Functional MRI scan shows the visual cortex (occipital lobes) activated as the subject looks at faces
Visual and Auditory Visual and Auditory CortexCortexpage 80
Temporal Lobes
Occipital Lobes
Association AreasAssociation Areaspage 81
More intelligent animals have increased “uncommitted” or association areas of the cortex
The Cerebral Cortex & The Cerebral Cortex & LanguageLanguage
Aphasia impairment of language, usually caused
by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding)
Broca’s Area an area of the left frontal lobe that
directs the muscle movements involved in speech
Wernicke’s Area an area of the left temporal lobe involved
in language comprehension and expression
Specialization and Specialization and IntegrationIntegration
Specialization and Specialization and IntegrationIntegration
Brain activity when hearing, seeing, and speaking words
The Cerebral Cortex:The Cerebral Cortex:Brain ReorganizationBrain Reorganization
Plasticity the brain’s capacity for modification, as
evident in brain reorganization following damage (especially in children) and in experiments on the effects of experience on brain development Children have a surplus of neurons When one area is damaged, other areas may
in time reorganize and take over some of its functions
“stem cell research”
Our Divided BrainSOur Divided BrainS
Corpus Callosum
large band of neural fibers
connects the two brain hemispheres
carries messages between the hemispheres
Corpus callosum
Our Divided BrainsOur Divided Brains
The information highway from the eye to the brain
The opposite side of the brain’s hemisphere controls the opposite side of the body
The Hemispheres of the The Hemispheres of the BrainBrain
Clinical neurologists Gereon Fink of the University of Düsseldorf in Germany and John Marshall from the Radcliffe Infirmary in Oxford,
pursued the idea that the difference between the two
hemispheres lay in their style of working.
““The left brain does The left brain does the work that no one the work that no one
in their right mind in their right mind would want to do.”would want to do.”
-Amanda Barrow1st period
• The left brain focuses on detail. • It is the natural home for all mental skills that need us to act in a series of
discrete steps or fix on a particular fragment of what we perceive.
• skills such as recognizing a friend's face in a crowd or "lining up" words
to make a sentence.
The Left The Left HemisphereHemisphere
(Verbal)(Verbal)
LEFT Hemisphere LEFT Hemisphere FUNCTIONSFUNCTIONS
Speech
Language
Logic
Writing
RIGHT RIGHT HemisphereHemisphere
FUNCTIONSFUNCTIONS•concentrates on the broad,
background picture.
•It has a panoramic focus..
•good at seeing general connections
•best able to represent the relative position of objects in space
•handles emotional and metaphorical aspects of speech.
Right Hemisphere Right Hemisphere FunctionsFunctions
Spatial Reasoning
Art
Music
Emotions
• So, in a neat and complementary division of labor, one side of the brain thinks and sees in wide-angle while the other zooms in on the detail.
• To examine the functions carried out by each hemisphere, neurologists scanned the brain of subjects while they were shown a series of letter navons. A letter navon is a large letter composed of smaller letters as shown in the side box. The researchers soon found out that while the subjects concentrated on the small F's, the left hemisphere showed greater activity; when they focused on the big S, the right hemisphere became active.
• Thus, they had
demonstrated that the left hemisphere focused on the details, while the right perceived the overall, background picture.
Split BrainSplit Brain
A condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (corpus callosum) between them.
Split BrainSplit Brain Sperry & Gazzaniga
“Look at the dot.” Two words separatedby a dot are momentarily projected.
“What worddid you see?”
or
“Point withyour left hand to theword you saw.”
Test yourself for Split Test yourself for Split BrainBrain
• Perform the following task simultaneously. You should be able to do both tasks with ease if you are split-brain
• Draw a picture of a house; include windows, door, chimney with either hand
• With the other hand, write your first and last name in cursive writing.
• You can’t stop one task to work the other!
Disappearing Disappearing SouthpawsSouthpaws
The percentage of left-handers decreases sharply in samples of older people (adapted from Coren, 1993).
The percentage of lefties sharplydeclines with age
10 20 30 40 50 60 70 80 90Age in years
14%
12
10
8
6
4
2
0
Percentage ofleft-handedness
All Hands of DeckAll Hands of Deck Answer the following questions on p.89-91
HW GRADE
1. % of population lefties
2. More males or females?
3. Inherited?4. Pre-cultural?5. Cultural influence?6. Human –vs- animal7. Identical twins?8. Right head/left
head babies
9. Do we mean what we say?
10. Problems that lefties have
11. Occupations of lefties12. Famous lefties13. Why do lefties
disappear with age?14. Known health risks15. Leftie life span16.Evolutionary
explanation?
• A team of biologists and chemists is closing in on bringing non-living matter to life.
• Jack Szostak, a molecular biologist at Harvard Medical School, is building simple cell models that can almost be called life.
• protocells are built from fatty molecules that trap bits of nucleic acids that contain the source code for replication.
• It harnesses external energy from the sun or chemical reactions,
• could form a self-replicating, evolving system that satisfies the conditions of life
• isn't anything like life on earth now, but might represent life as it began or could exist elsewhere in the universe.
• these genes would launch the new form of life down the Darwinian evolutionary path
• researchers are trying to design a completely novel form of life that humans have never seen and that may never have existed.
The Future of The Future of NeuroscienceNeuroscience
PSYCHOLOGY PSYCHOLOGY EXPERIMENTEXPERIMENT
“WHICH WAY DO THE EYES MOVE”
DID YOU KNOW?DID YOU KNOW?
• The direction your eyes move when you think about a question may indicate which side of the brain you are using for the answer.
• Ask 2 friends the following list of questions and secretly watch whether they first look to the left or to the right as they consider each.
QUESTION ONE
1. Make up a question using the words “code and mathematics”
QUESTION TWO
2. Picture the last automobile accident you saw. In which direction were the cars going?
QUESTION THREE
3. What does the proverb “Easy come, easy go” mean?
QUESTION FOUR
4. Picture and describe the last time you cried.
DATA• Record which direction the
person looks on each question.
• Questions 1 and 3 are verbal, non-emotional questions. The subject should use the left hemisphere to answer and as a result, tends to look to the right.
• Questions 2 and 4 are spatial-emotional questions that require the right hemisphere and should yield more eye movements to the left.
RESULTSRESULTS
• Summarize your results in a short paragraph which includes your analysis of the recorded data, any inconsistencies you found, and any problems you may have encountered administering this test.
RESPONSE PAPERRESPONSE PAPER
Subject 1 Subject 2Right RightLeft LeftRight RightLeft Left
• Summary: Summary:• Problems encountered:• Signatures of subjects
Neural and Hormonal Neural and Hormonal SystemsSystems
Neural CommunicationNeural Communication
Biological Psychology
branch of psychology concerned with the links between biology and behavior
some biological psychologists call themselves behavioral neuroscientists, neuropsychologists,
behavior geneticists, physiological psychologists, or biopsychologists
Neural CommunicationNeural CommunicationNeuron
a nerve cell the basic building block of the nervous system
cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells.
Dendrite the bushy, branching extensions of a neuron that
receive messages and conduct impulses toward the cell body
Axon the extension of a neuron, ending in branching
terminal fibers, through which messages are sent to other neurons or to muscles or glands
Myelin [MY-uh-lin] Sheath a layer of fatty
cells segmentally encasing the fibers of many neurons
enables vastly greater transmission speed of neutral impulses
Neural Neural CommunicationCommunication
Neural CommunicationNeural Communication
Neural CommunicationNeural Communication
Action Potential a neural impulse; a brief electrical
charge that travels down an axon generated by the movement of
positively charged atoms in and out of channels in the axon’s membrane
Threshold the level of stimulation required to
trigger a neural impulse
Neural CommunicationNeural CommunicationSynapse [SIN-aps]
junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron
tiny gap at this junction is called the synaptic gap or cleft
Neurotransmitters chemical messengers that travel the
synaptic gaps between neurons when released by the sending neuron,
neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether it will generate a neural impulse
Neural CommunicationNeural Communication
Cell body end of axon
Direction of neural impulse: toward axon terminals
Neural CommunicationNeural Communication
FILMChapter 2: Embryonic and Fetal Brain Development (13 min 28 sec) Safari Montagehttp://videoservicesondemand.volusia.k12.fl.us/SAFARI/montage/schoolnews.html
FLUSHING TOILETFLUSHING TOILET• All or None Principle:
once the handle is pushed and the toilet begins flushing, there is no stopping it.
• Once a neuron is fired, it cannot be stopped or it’s message taken back
• Like a gun, either a neuron fires or it doesn’t.
• The strength of the stimulus does not affect the action potential speed.
Direction of Impulse• A toilet only flows
one way-out into the sewage system. The direction never changes. A toilet that is working properly never flows up.
• A neuron always fires the impulse in a specific direction- towards the target
Refractory Period• Brief period of
time after you flush the toilet during which the handle is useless and the toilet cannot be flushed again.
• Same for a neuron, which limits the number of times a neuron can be fired per second.
• A camera flash that pauses to recharge
THRESHOLD:• There is a specific
level of intensity and a limit to the volume that it is possible to flush down a toilet
• The amount of pressure required to push the trigger to flush the toilet
• When a toilet is being flushed, a minimum intensity of water pressure is needed in order for the toilet to function properly.
• The level of stimulation required to trigger a neural impulse.
Resting Potential• When the toilet is not
being flushed, no water moves in or out and is stable. Ready to be flushed immediately
• When a neuron is at rest it too is stable
• A resting axon has an excess of neg. charged ions inside and the fluid outside of an axon membrane has an excess of pos. charged ions.
Action Potential• A neural impulse• Brief electrical
charge that travels down an axon
• When a neuron’s receptor is stimulated, ions rush in and energy flows down the axon
• The toilet handle is pushed to initiate water rushing into and flowing down the toilet
Depolarization• Pushing the handle
stimulates the toilet into action. New water coming into the bowl. the flow of positively charged ions into the axon leads the axon to become positively charged relative to the outside.
• Causes the next channel to open.
• Domino effect
DepolarizationDepolarization
Neural CommunicationNeural Communication
Neural CommunicationNeural Communication
Serotonin Pathways Dopamine Pathways
Neural CommunicationNeural Communication
Acetylcholine [ah-seat-el-KO-leen] a neurotransmitter that, among its
functions, triggers muscle contraction
Endorphins [en-DOR-fins] “morphine within” natural, opiate-like neurotransmitters linked to pain control and to pleasure
Neural CommunicationNeural Communication
Neurotransmitter molecule
Receiving cellmembrane
Receptor site onreceiving neuron
Agonist mimicsneurotransmitter
Antagonistblocksneurotransmitter
Agonist –vs- AntagonistAgonist –vs- Antagonist
• Excitatory• Can mimic the nt• Can block nt’s
reuptake• Opiates enhance
normal arousal or sensation of pleasure
• Ecstacy enhances sexual arousal
• Inhibitory• Prevents the nt’s
release• Or occupy its
receptor site and block its effect
• Is similar but not enough to stimulate the receptor
• Foreign money in a snack machine
Ecstasy commonly appears in a tablet form, usually imprinted with a monogram Neurotransmitter Agonist. Film: Club Drugs
• MDMA (3,4-methylenedioxymethamphetamine), most commonly known by the street names ecstasy or XTC primary effect is believed to be the stimulation of secretion as well as inhibition of re-uptake of large amounts of serotonin as well as dopamine and norepinephrine in the brain, inducing a general sense of openness, empathy, energy, euphoria, and well-being. Tactile sensations are enhanced for some users, making general physical contact with others more pleasurable;
• Good medical use has been the reported ability to facilitate self-examination with reduced fear may prove useful in some therapeutic settings, 2001: permission granted to FDA for testing in patients with post-traumatic stress disorder .
BOTOXBOTOXAntagonistAntagonist
• botox is toxic compound. It is an enzyme that breaks down one of the fusion proteins that allow neurons to release acetylcholine. Small doses block the release of acetylcholine by nerve cells that signal muscle contraction.
• Botox originally produced for the intended relief of uncontrollable muscle spasms. First approved in 1989 to treat two eye muscle disorders--uncontrollable blinking (blepharospasm) and misaligned eyes (strabismus
• Increasingly being used for cosmetic purposes, to paralyse facial muscles as a means of concealing wrinkles.
NICOTINENICOTINEAgonistAgonist
• an increase in acetylcholine causes a decreased heart rate and increased production of saliva.
• Nicotine acts by increasing the activity of
certain acetylcholine receptors Nicotine is a potent nerve poison and is included in many insecticides.
• In lower concentrations, is a stimulant and one of the main factors leading to the pleasure and habit-forming qualities of tobacco smoking.
NEUROTRANSMITTER NEUROTRANSMITTER ANTAGONISTANTAGONIST
• Curare is a potent neurotoxin. Used as an arrow poison by some Indian peoples of South America
• Death from curare is caused by loss of the ability to breathe as a result of paralysis. The alkaloid curare molecule mimics the neurotransmitter acetylcholine by binding to its receptor at muscle synapses. This prevents nerves from stimulating muscle contraction.
NEUROTRANSMITTERNEUROTRANSMITTERAgonistAgonist
• The venom of a black widow spider causes a synaptic flood of ACH.
• Results in violent muscle contractions, convulsions, and possible death.
Bipolar DisordersBipolar Disorders• occurs with equal frequency in
men and women. The peak age of onset is during late teens.
• Neurotransmitter abnormalities in a number of pathways including serotonin, norepinephrine, dopamine, acetylcholine
• thalamus, hypothalamus, amygdala, prefrontal cortex, and cerebellum.
““All Hands on Deck”All Hands on Deck”EndorphinsEndorphins
Endorphins: page 63 Read the section on “The Endorphins”
Answer the following questions1. “How do drugs/other chemicals alter
neurotransmission?2. What was the Pert and Snyder 1973
finding?3. What is Endogenous?4. Interpret David Livingstone”s 1857
Missionary Travels in regards to the role endorphins play.
5. What is meant by “Biological Mercy” by Physician Lewis Thomas
6. What is the price that Nature charges?
The Nervous The Nervous SystemSystem
Nervous System the body’s speedy, electrochemical
communication system consists of all the nerve cells of the
peripheral and central nervous systems
Central Nervous System (CNS) the brain and spinal cord
Peripheral Nervous System (PNS) the sensory and motor neurons that
connect the central nervous system (CNS) to the rest of the body
The Nervous SystemThe Nervous System
Central(brain and
spinal cord)
Nervoussystem
Autonomic (controlsself-regulated action of
internal organs and glands)
SomaticSkeletal (controls
voluntary movements ofskeletal muscles)
Sympathetic (arousing)
Parasympathetic (calming)
Peripheral
The Nervous SystemThe Nervous System
Nerves neural “cables” containing many axons part of the peripheral nervous system connect the central nervous system
with muscles, glands, and sense organsSensory Neurons
neurons that carry incoming information from the sense receptors to the central nervous system
The Nervous SystemThe Nervous System
Interneurons CNS neurons that internally communicate
and intervene between the sensory inputs and motor outputs
Motor Neurons carry outgoing information from the CNS
to muscles and glands
Peripheral Nervous SystemPeripheral Nervous System1. Somatic Nervous System – voluntary
(skeletal)
2. Autonomic nervous system- involuntary (glands/muscles)
Peripheral Nervous Peripheral Nervous SystemSystem
Somatic Nervous System the division of the peripheral
nervous system that controls the body’s skeletal muscles
The Nervous The Nervous SystemSystem
Autonomic Nervous System the part of the peripheral nervous
system that controls the glands and the muscles of the internal organs (such as the heart)
A. Sympathetic Nervous System division of the autonomic nervous
system that arouses the body, mobilizing its energy in stressful situations
B. Parasympathetic Nervous System division of the autonomic nervous
system that calms the body, conserving its energy
The Nervous SystemThe Nervous System
The Nervous SystemThe Nervous System
The Nervous SystemThe Nervous SystemReflexReflex a simple, automatic, inborn response to a
sensory stimulus
Skinreceptors
Muscle
Sensory neuron(incoming information)
Motor neuron(outgoing information)
Brain
Interneuron
Spinal cord
The Nervous SystemThe Nervous System
Neural Networks interconnected
neural cells with experience,
networks can learn, as feedback strengthens or inhibits connections that produce certain results
Inputs Outputs
Neurons in the brain connect with one
another to form networks
The brain learns by modifyingcertain connections in response to feedback
The Endocrine SystemThe Endocrine System
Endocrine System the body’s
“slow” chemical communication system
a set of glands that secrete hormones into the bloodstream
Neural and Hormonal Neural and Hormonal SystemsSystems
Hormones chemical messengers, mostly those
manufactured by the endocrine glands, that are produced in one tissue and affect another
Adrenal [ah-DREEN-el] Glands a pair of endocrine glands just above the kidneys secrete the hormones epinephrine (adrenaline)
and norepinephrine (noradrenaline), which help to arouse the body in times of stress
Pituitary Gland under the influence of the hypothalamus, the
pituitary regulates growth and controls other endocrine glands
• The adrenal glands are orange-colored endocrine glands which are located on the top of both kidneys
Pituitary GlandPituitary Gland
The Master Gland• Prolactin - Prolactin stimulates milk production from the breasts after
childbirth • Growth hormone or GH - GH stimulates growth in childhood • In adults it is important for maintaining muscle mass as well as bone
mass. It also affects fat distribution in the body. • Adrenocorticotropin or ACTH - ACTH stimulates production of
cortisol by the adrenal glands. Cortisol, a so-called "stress hormone" is vital to survival
• Luteinizing hormone or LH - LH regulates testosterone in men and estrogen in women.
• Follicle-stimulating hormone or FSH - FSH promotes sperm production in men and stimulates the ovaries to enable ovulation in women
• Thyroid-stimulating hormone or TSH - TSH stimulates the thyroid gland, which regulates the body's metabolism, energy, growth and development
• Follicle-stimulating hormone or FSH - FSH promotes sperm production in men and stimulates the ovaries to enable ovulation in women
• "Gene Therapy": production of transgenic mice• Mice homozygous for a dwarfism gene (lit / lit) grow at a slow rate. An artificial plasmid (top
left) is constructed that combines a rat growth-hormone (RGH) gene fused to a mouse metallothionein promoter (MP) gene. A large number of these plasmids are then injected into fertilized eggs of mice; in a small fraction of cases the plasmid is stabily integrated into the mouse's chromosomes. Production of RGH can then be induced by exposure of the embryo to heavy-metals, which activates the MP promoter. The resulting transgenic offspring (left) weighs 44g (its control sibling weighs 29g). The recombinant chromosome is subsequently inherited in a Mendelian dominant pattern.
Gigantism• Gigantism is an
excessive secretion of growth hormone during childhood before the closure of the bone growth plates, which causes overgrowth of the long bones and very tall stature. he vertical growth in height that marks this condition is also accompanied by growth in muscles and organs, which makes the child extremely large for his or her age. The disorder can also delay puberty.
• Macrosomia is the condition of having an unusually large body. The body is in proportion, with the extremities and head also enlarged. Disorders that include this condition are gigantism and acromegaly.
The Doughnut AssignmentThe Doughnut Assignment
• Select a doughnut that best represents your limbic system
• Place skittles in the sequential order for the following:
• Hypothalamus: green skittle• Pituitary gland: yellow skittle• Amygdala: 2 peanut M&Ms• Hippocampus: orange skittle• “Bon Appetite”
1. Which of the following parts of the brain is most active in decision-making?
(a) Reticular formation(b) Corpus Callosum(c) Hypothalamus(d) Cerebral cortex(e) Pituitary gland2. An individual experiencing a low blood- glucose level would
be best advised to do which of the following?(a) take a nap(b) eat a snack(c) drink a glass of water(d) drink a diet soda(e) get some exercise
3.One suspected cause of schizophrenia is the abnormal increase of which of the following neurotransmitters in the brain?
(a) Acetylcholine(b) Somatotropin(c) Dopamine(d) Norepinephrine(e) serotonin4.For most people, speech functions are primarily localized in the(a) right Cerebral hemisphere(b) left cerebral hemisphere(c) Occipital lobe(d) Corpus Callosum(e) Cerebellum
5. People who have experienced severe damage to the frontal lobe of the brain seldom regain their ability to
(a) make and carry out plans(b) recognize visual patterns(c) process auditory information(d) process olfactory information(e) integrate their multiple personalities6. Which of the following is a brain-imaging technique that
produces the most detailed picture of brain structure?• (a) Electroencephalography (EEG)• (b) Magnetic Resonance Imaging (MRI)• (c) Positron Emission Tomography (PET)• (d) Computerized Axial Tomography (CAT)• (e) Electromyography (EMG)
7. Stimulations of portions of the left temporal lobe of the brain during surgery will cause the patient to
(a) see lights(b) lose the sense of smell(c) jerk the left arm(d) extend the tongue(e) hear sounds8. The role of the parasympathetic division of autonomic nervous
system is to(a) facilitate the body’s fight-or-flight response(b) prepare the body to cope with stress(c) promote rapid cognitive processing(d) prompt the body to use its resources in responding to
environmental stimuli (e) establish homeostasis after a fight-or-flight response
9. Which of the following occurs when a neuron is stimulated to its threshold?
(a) the movement of sodium and potassium ions across the membrane creates an action potential
(b) the neuron hyperpolarizes.(c) neurotransmitters are released from the dendrites(d) the absolute refractory period of the neuron prevents it from
responding.(e) the neuron’s equilibrium potential is reached10. The thalamus processes information for all of the following
senses EXCEPT(a) smell(b) hearing(c) taste(d) vision(e) touch
