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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