Chapter 3 and Chapter 4Cells and body organization

CELL STRUCTURE AND FUNCTION

CELLS

TINY UNITS OF LIVING MATERIAL VARY IN SIZE AND SHAPE CHICKEN EGG- LARGE MOST ARE VERY SMALL

WHY ARE CELLS SO SMALL?

A CELL’S SURFACE IS THE GATE THAT FOOD AND OXYGEN MUST ENTER AND WASTES MUST EXIT

AS A CELL’S SIZE INCREASES, THE AMOUNT OF SURFACE AREA FOR THIS EXCHANGE DECREASES RELATIVE TO THE VOLUME

SUFFOCATION RESULTS IF SURFACE AREA IS TOO SMALL

LOOKING AT CELLS

MICROSCOPES ARE VERY USEFUL LIGHT MICROSCOPES- GOOD ELECTRON MICROSCOPES- MUCH

MORE POWERFUL, VERY EXPENSIVE

CELLULAR ORGANELLES

ORGANELLES= THE CELL’S TINY ORGANS

PLASMA MEMBRANE- SURROUNDS THE CELL

CYTOPLASM- THE FLUID INSIDE THE CELL MEMBRANE

NUCLEUS- THE CELL’S CONTROL CENTER

NUCLEUS

CONTAINS DNA= THE BLUEPRINT FOR THE CELL

THE INFORMATION STORED IN DNA TELLS THE CELL HOW TO MAKE PROTEINS

HAS ITS OWN MEMBRANE

NUCLEOLUS- CENTER OF NUCLEUS RIBOSOMES ARE MADE HERE

IN THE CYTOPLASM...

RIBOSOMES- MAKE PROTEINS ER (ENDOPLASMIC RETICULUM)-

PACKAGES PROTEINS -SMOOTH ER- LIPID SYNTHESIS -ROUGH ER- RIBOSOMES ON THE SURFACE

GOLGI- PROCESSES PROTEINS AND REPACKAGES THEM

SIGHTS OF THE CYTO.

LYSOZOMES- STORAGE OF ENZYMES FOR DIGESTION

MITOCHONDRION- BURNS GLUCOSE AND PRODUCES ENERGY (ATP)

CENTRIOLS- PRODUCE AND ORGANIZE MICROTUBULES (CYTOSKELETON)

CILIA AND FLAGELLA

EXTERNAL STRUCTURES USED TO MOVE THE CELL OR ITS

ENVIRONMENT MADE OF MICROTUBULES

CILIA- SHORT, OARLIKE- WINDPIPE

FLAGELLA- LONG, WHIPLIKE -SPERM

PLASMA MEMBRANE

A PHOSPHOLIPID BILAYER (DOUBLE LAYER OF PHOSPHOLIPIDS)

SELECTIVELY PERMEABLE- PICKY ABOUT WHAT GETS THROUGH

HAS EMBEDDED PROTEINS THAT SERVE AS CHANNELS AND CARRIERS

GLYCOPROTEINS- CELLULAR IDENTIFICATION

FUNCTION

OXYGEN AND CARBON DIOXIDE PASS FREELY THROUGH THE MEMBRANE

OTHER MOLECULES MUST USE A CHANNEL PROTEIN OR CARRIER TO CROSS

WATER- USES A PROTEIN CHANNEL TO PASS THROUGH

DIFFUSION

THE RANDOM MOVEMENT OF MOLECULES FROM AN AREA OF HIGHER CONCENTRATION TO AN AREA OF LOWER CONCENTRATION

OSMOSIS- THE DIFFUSION OF WATER ACROSS A PLASMA MEMBRANE

PASSIVE TRANSPORT- NO ENERGY IS REQUIRED

TONICITY

AFFECTS THE MOVEMENT OF WATER- BASED ON SOLUTE CONC.

ISOTONIC- WATER AND SOLUTE CONC. OF CELL AND FLUID ARE EQUAL

HYPOTONIC- FLUID HAS LESS SOLUTES/MORE WATER- CELLS SWELL

HYPERTONIC- FLUID HAS MORE SOLUTES/LESS WATER- CELLS SHRIVEL

TRANSPORT BY CARRIERS

FACILITATED TRANSPORT- SUBSTANCE IS MOVING DOWN ITS CONCENTRATION GRADIENT (DIFFUSION)- THESE LARGER MOLECULES NEED A PROTEIN CARRIER TO GET THROUGH THE MEMBRANE - NO ENERGY IS USED

MORE ON TRANSPORT...

ACTIVE TRANSPORT- SUBSTANCE IS PUMPED AGAINST THE CONCENTRATION GRADIENT

WORKS AGAINST DIFFUSION

- REQUIRES A PROTEIN CARRIER

- USES ENERGY

IN AND OUT

ENDOCYTOSIS- LARGE SUBSTANCES ARE “ENGULFED” BY THE CELL USING A PIECE OF THE CELL MEMBRANE

EXOCYTOSIS- A VESICLE FORMED BY THE GOLGI FUSES WITH THE PLASMA MEMBRANE AND DUMPS ITS CONTENTS OUT OF THE CELL

THE NUCLEUS

NORMALLY THE DNA IS IN AN UNCOILED STATE CALLED CHROMATIN

WHEN THE CELL GETS READY TO DIVIDE, THE DNA COILS UP INTO THICK STRUCTURES CALLED CHROMOSOMES

NUCLEAR ENVELOPE

SEPARATES THE NUCLEUS FROM THE REST OF THE CELL

A DOUBLE MEMBRANE NUCLEAR PORES- OPENINGS IN

THE NUCLEAR ENVELOPE THAT ALLOW PROTEINS AND RNA TO PASS

MEMBRANES

ENDOPLASMIC RETICULUM, GOLGI APPARATUS AND VACUOLES ARE ORGANELLES COMPOSED MAINLY OF MEMBRANES

ER- A SYSTEM OF TUBULAR CANALS

ROUGH- RIBOSOMES ON SURFACE

SMOOTH- NO RIBOSOMES VACUOLE- A STORAGE SACK

GOLGI APPARATUS

HOLLOW PANCAKES PACKAGES STORES AND

DISTRIBUTES PROTEINS MADE BY ROUGH ER

SOMETIMES THESE SUBSTANCES ARE MOVED OUT OF THE CELL- EX. DIGESTIVE ENZYMES

LYSOSOME

CONTAINS DIGESTIVE ENZYMES DIGESTS PARTICLES TAKEN IN BY

ENDOCYTOSIS AUTODIGESTION- “CELLULAR

SUICIDE”- REMOVES WEBBING FROM BETWEEN OUR FINGERS WHILE WE ARE EMBRYOS

MITOCHONDRIA

ATP ARE PRODUCED HERE AS GLUCOSE IS “BURNED”

OXYGEN IS USED AND CARBON DIOXIDE AND WATER ARE RELEASED A WASTE PRODUCTS

AEROBIC CELLULAR RESPIRATION

CYTOSKELETON

HELPS MAINTAIN THE CELLS SHAPE ANCHOR OR MOVE THE

ORGANELLES AROUND INSIDE THE CELL

MICROTUBULES- DIVIDE THE CELL DURING DIVISION, FLAGELLA (SPERM)

CELLULAR METABOLISM

ALL THE CHEMICAL REACTIONS THAT OCCUR IN A CELL

EVERY REACTION IN A CELL REQUIRES A SPECIFIC ENZYME

REACTANTS- STARTING MATERIALS FOR A REACTION

PRODUCTS- RESULT OF A REACTION

ENZYMES

PROTEINS THAT SPEED UP A REACTION

AN ENZYME WILL ACT ON A SPECIFIC MOLECULE CALLED A SUBSTRATE

HAVE AN ACTIVE SITE WHERE THE SUBSTRATES BIND AND ARE CHANGED

COENZYMES

NON-PROTEIN MOLECULES THAT ASSIST THE ENZYME IN ITS “WORK”

EX. VITAMINS- HELP YOUR ENZYMES

AEROBIC CELLULAR RESP.

GLUCOSE + OXYGEN= WATER + CARBON DIOXIDE + ENERGY (ATP)

MAKES 36 ATP/GLUCOSE NAD+ = AN IMPORTANT HYDROGEN

CARRIER 3 STEPS- GLYCOLYSIS, KREB’S

CYCLE, ELECTRON TRANSPORT SYSTEM

FERMENTATION

ANAEROBIC- DOES NOT REQUIRE OXYGEN

PRODUCES ONLY 2 ATP/GLUCOSE OCCURS IN MUSCLES DURING

HEAVY USE PRODUCES LACTIC ACID WHICH

MAKES YOUR LEGS ACHE

HUMAN ORGANIZATION

TISSUE

SIMILAR CELLS THAT PERFORM A SIMILAR FUNCTION

4 MAJOR TYPES OF TISSUES

1. EPITHELIAL- COVERS BODY SURFACES AND LINES BODY CAVITIES

2. CONNECTIVE- BINDS AND SUPPORTS BODY PARTS

3. MUSCLE- MOVES BODY PARTS

4. NERVOUS- RECEIVES STIMULI AND CONDUCTS IMPULSES FORM ONE PART TO ANOTHER

EPITHELIAL TISSUE

CELLS ARE TIGHTLY PACKED TOGETHER TO FORM A LAYER

SKIN LINING OF DIGESTIVE TRACT,

CIRCULATORY SYSTEM, RESPIRATORY TRACT

3 TYPES OF EPITHELIUM

SQUAMOUS- COMPOSED OF FLATTENED CELLS- EX. LINES BLOOD VESSELS

CUBOIDAL- CUBE SHAPED CELLS- EX. KIDNEY TUBULES

COLUMNAR- RECTANGULAR PILLAR SHAPED CELLS- EX. DIGESTIVE TRACT LINING

LAYERS OF EPITHELIAL CELLS

SIMPLE- ONE LAYER OF CELLS

STRATIFIED- SEVERAL LAYERS OF CELLS ARE STACKED ON TOP OF EACH OTHER

PSEUDOSTRATIFIED- APPEARS TO BE LAYERED BUT SOME CELLS SPAN BOTH LAYERS

SPECIAL EPITHELIAL CELLS

CILIATED- HAVE CILIA WHICH MOVE OTHER PARTICLES - EX. TRACHEA

GLAND CELLS- SECRETE SUBSTANCES- 2 TYPES

ENDOCRINE- SECRETE SUBSTANCES INTO THE BLOODSTREAM

EXOCRINE- USE DUCTS FOR SECRETIONS

BETWEEN CELLS...

3 TYPES OF JUNCTIONS

TIGHT JUNCTIONS- FORM A SEAL BETWEEN 2 CELLS- DIGESTIVE TRACT

GAP JUNCTION- OPEN CHANNEL BETWEEN 2 CELLS- ALLOWS COMMUNICATION- HEART

ADHESION- HOLD CELLS TOGETHER- HEART

CONNECTIVE TISSUE

VERY DIVERSE BINDS ORGANS TOGETHER,

PROVIDES SUPPORT AND PROTECTION. FILLS SPACES, PRODUCES BLOOD CELLS AND STORES FAT

CELLS USUALLY SEPARATED BY A MATRIX

MATRIX

SEPARATES CELLS OF CONNECTIVE TISSUE

CAN BE SOLID, SEMISOLID OR EVEN FLUID (BLOOD PLASMA)

LOOSE CONNECTIVE TISSUE

MAIN FUNCTION IS SUPPORT MADE UP MAINLY OF CELLS CALLED

FIBROBLASTS

ADIPOSE TISSUE- STORES FAT

RETICULAR TISSUE- LYMPH NODES, SPLEEN, BONE MARROW, THYMUS- IMMUNE SYSTEM- STORE OR PRODUCE WHITE BLOOD CELLS

FIBROUS CON. TISSUE

BINDS BODY PARTS TOGETHER TENDONS- CONNECT MUSCLES TO

BONES LIGAMENTS- CONNECT BONES

TOGETHER AT JOINTS CARTILAGE- A STRUCTURAL

CONNECTIVE TISSUE

CARTILAGE

FLEXIBLE NO DIRECT BLOOD SUPPLY SO IT

HEALS VERY SLOWLY

3 TYPES

HYALINE- MOST COMMON- NOSE AND AT THE ENDS OF LONG BONES

ELASTIC- FLEXIBLE- EAR

CARTILAGE CONT.

FIBROCARTILAGE- CAN WITHSTAND TENSION AND PRESSURE- BETWEEN VERTEBRAE, KNEE JOINTS

BONE

RIGID- HARD MATRIX

COMPACT BONE- SHAFTS OF LONG BONES

SPONGY BONE- ENDS OF BONES LESS DENSE THAN COMPACT BONE

BUT STILL STRONG

BLOOD

HAS A LIQUID MATRIX CALLED PLASMA (55% OF THE VOLUME)

3 SOLID COMPONENTS

RED BLOOD CELLS- NO NUCLEUS, CARRY OXYGEN TO OTHER CELLS

WHITE BLOOD CELLS- HAVE A NUCLEUS, FIGHT INFECTION

PLATELETS- CELL FRAGMENTS, CLOT

MUSCLE

CONTAIN ACTIN AND MYOSIN FILAMENTS WHICH ARE RESPONSIBLE FOR THE CONTRACTION

3 TYPES

1. SKELETAL

VOLUNTARY CONTROL ATTACHED TO BONES MULTINUCLEATED STRIATED- ALTERNATING LIGHT

AND DARK BANDS DUE TO THE PLACEMENT OF ACTIN AND MYOSIN FILAMENTS

2. SMOOTH

NO STRIATIONS NOT VOLUNTARY FOUND IN DIGESTIVE, CIRCULATORY

AND OTHER SYSTEMS CONTRACTS MORE SLOWLY THAN

SKELETAL MUSCLE , BUT IT CAN REMAIN CONTRACTED FOR A LONGER TIME

3. CARDIAC MUSCLE

FOUND ONLY IN THE WALLS OF THE HEART

HAS STRIATIONS LIKE SKELETAL MUSCLE, BUT IT IS NOT UNDER VOLUNTARY CONTROL

COMMUNICATION TO SYNCHRONIZE CONTRACTIONS IS DUE TO GAP JUNCTIONS BETWEEN THE CELLS

NERVOUS TISSUE

CONDUCTS ELECTRICAL IMPULSES MADE OF CELLS CALLED NEURONS THAT

CARRY THE IMPULSE

3 PARTS- AXON= AWAY DENDRITE= TOWARD CELL BODY= CENTRAL PART

NERVE- CLUSTER OF NEURONS NEUROGLIAL CELLS- SUPPORT AND

PROTECT NEURONS

SKIN- AN ORGAN

ORGAN= COMPOSED OF TWO OR MORE TISSUES

3 LAYERS

EPIDERMIS- EPITHELIUM

DERMIS- CONNECTIVE, MUSCLE, NERVOUS, EPITHELIUM (GLANDS)

SUBCUTANEOUS- CONNECTIVE TISSUE- LAYER OF FAT

SKIN CANCER

MALIGNANT MELANOMA- DARKLY PIGMENTED SPOT THAT LOOKS LIKE A MOLE- UV LIGHT

BASAL CELL AND SQUAMOUS CELL CARCINOMAS- EPIDERMAL CELLS, UV LIGHT, SURGICAL REMOVAL

MAJOR BODY CAVITIES

THORACIC- SUBDIVIDED INTO CAVITIES THAT CONTAIN THE HEART AND LUNGS

ABDOMINAL- SEPARATED FROM THE THORACIC CAVITY BY THE DIAPHRAGM. CONTAINS MOST OF THE DIGESTIVE SYSTEM

MEMBRANES

A LAYER OF EPITHELIAL CELLS THAT LINE BODY SURFACES

MUCOUS- LINE THE DIGESTIVE, RESPIRATORY, URINARY AND REPRODUCTIVE SYSTEMS

SEROUS- LINE THORACIC AND ABDOMINAL CAVITIES + ORGANS

SYNOVIAL-JOINTS BETWEEN BONES

MENINGES-BRAIN

ORGAN SYSTEMS

WORK TOGETHER TO MAINTAIN THE BODY’S INTERNAL ENVIRONMENT

MAINTENANCE CIRCULATORY DIGESTIVE URINARY LYMPHATIC RESPIRATORY

ORGAN SYSTEMS CONT.

INTEGUMENTARY- SKIN

ORGAN SYSTEMS CONT.

SUPPORT AND MOVEMENT SKELETAL MUSCULAR

ORGAN SYSTEMS CONT.

INTEGRATION AND COORDINATION NERVOUS ENDOCRINE

REPRODUCTION REPRODUCTIVE

HOMEOSTASIS

INTERNAL ENVIRONMENT REMAINS CONSTANT EX. CONSTANT BODY TEMP, BLOOD PRESSURE ETC.

REQUIRES THAT ORGAN SYSTEMS WORK TOGETHER TO KEEP CELLS WARM, WELL FED, DISEASE AND WASTE FREE AND HAPPY!

MAINTAINING BALANCE

NEGATIVE FEEDBACK- PROCESS BY WHICH THE BODY CORRECTS ITSELF TO NEGATE THE ORIGINAL PROBLEM

NERVOUS AND ENDOCRINE SYSTEMS REACT TO PROBLEMS AND CORRECT THEM

EX. BODY TEMPERATURE

BLOOD TEMP MEASURED BY THE HYPOTHALAMUS (IN THE BRAIN)

TOO LOW- THEN NERVOUS IMPULSES SHUT DOWN BLOOD FLOW TO SKIN + BEGINS SHIVERING RESPONSE

TOO HIGH- THEN MORE BLOOD CIRCULATES TO SKIN SURFACE + SWEAT PRODUCTION