Zoology 3rd Exam

7/31/2019 Zoology 3rd Exam

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BUERANO (DONE!)HICKMAN (DONE!)RED: CAMPBELL

Extracellular Components of Metazoan Bodies1. Body Fluids (2 fluid compartments)

a. Intracellular space

b. Extracellular space

Blood plasma - fluid portion outside blood cells

Interstitial fluid tissue fluid (occupies the space surrounding cells)

2. Extracellular Structural Elementso Supportive material of the organism

o Mechanical stability and protection

o Composed of

a. Loose connective tissueb. Cartilagec. Boned. Cuticle

Body fluid of a single-celled organism is cellular cytoplasmo Liquid-gel substance in which the various membrane systems and organelles are suspended

o Multi-cellular animals

Intracellular phase collective fluid inside all the bodys cells

Extracellular phase fluid outside and surrounding the cellso Buffer from harsh physical and chemical changes occurring outside the body

embryonic tissues that give rise to all of the tissues, organs, and organ systems in the body

1. Ectoderm forms the outer layer of skin and nervous system

2. Mesoderm forms the muscles, connective tissues, skeleton, kidneys, and circulatory and reproductive

organs3. Endoderm

forms the lining of the gut, respiratory tract, and urinary bladder. It also forms the glandsassociated with the gut and respiratory tract

Dominant homeostatic defense (see figure)1. Blood coagulation2. Blood clots form as tangled networks of fibers from fibrinogen3. Fibirinogen is transformed into a fibrin meshwork that entangles blood cells to form a

gel-like clota. Catalyzed by the enzyme THROMBIN

- Normally present in blood in an inactive form (PROTHROMBIN)

- Must be activated for coagulation to occur

oThromboplastin

- Initiate conversion of prothrombin to active thrombin (for blood clotting)

HIERARCHY

atoms

complex biological molecules

subcellular organells

cells1. protozoa unicellular2. metazoa

o multicellular

o nor capable of independent existence

o specialized part of a whole organism

tissues (similar cells)

organs

organ systems

complex organism

population (group of organisms belonging to the same species)

community(populations living in the same area)

ecosystems (community + abiotic environmental factors)

biomes (large scale communities)

biosphere (sum of all the earth's ecosystems)LEVELS OF ORGANIZATION OF DIFFERENT ANIMALSFIVE MAJOR GRADES OF ORGANIZATION

Level of Organization Taxon of Representative

Animals

Representative Animals

1. protoplasmic grade of organizationo found in unicellular organisms

protozoa Amoeba proteus,Paramecium caudatum

2. cellularo aggregation of cells that are functionally

differentiated

protozoa

porifera

colonial protozoans(volvox)

sponges

3. cellular-tissueo aggregation of similar cells into definite patterns

or layers (tissue)

cnidaria(coelentarata)

hydra, jellyfish

4. t issue-organ platyhelminthes flatworms (planaria)

5. organ-systemo where different organs operate

o unifying organ: NOTOCHORD (located in the

vertebral column)

c hor dat a f rog , s hor tf in sc ad

STRUCTURAL ORGANIZATION IN HIGHER FORMS

Structural Unit Types/Kinds/Examples Field of Study Organ System Respiratory AnatomyReproductive

Endocrine

Muscular

Integumentary

Nervous

Immune

Skeletal

Circulatory

ExcretoryOrgan Examples: oral cavi ty , brain, pharynx, eye ,

liver, kidney, lungAnatomy

Tissuei.

a. Somatic1. epithelial2. connective3. muscular4. nervous

b. Reproductive1. sperm2. egg/oocyte

Histology

Cell same as in tissue Cytology (cell biology


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1. EPITHELIAL TISSUE

BASES OF CLASSIFICATION OVERALL CHARCTERISTICS(EPITHELIUM)

STRUCTURE OF EPITHELIAL TISSUES SPECIAL NAMES OF SOME EPITHELIAL TISSUE STRUCTURES ON FREE SU

a. shape of cellb. number of layersc. specialization of free surface (ciliated or

flaggelated)

sheet of cells that covers an externalor internal surface

outside: formation of protectivecovering

inside: lining of all organs of the bodycavity, as well as ducts andpassageways through which variousmaterials and secretions move

1. compact2. little intercellular substance3. polarized4. with basement "membrane" (basal lamina)

all types of epithelia are supported by an underlying membranes condensed region of ground substance of connective tissue secreted by both epithelial and

connective tissue cells

Name Characteristics 1. microvilli2. cil ia3. flagella4. stereocilia

1. mesothelium

o squamous cell lining serous cavities

such as:1. peritoneal cavites2. pleural cavities3. lining of visceral organs

2. endothelium

I. lining of blood vesselsII. lining of lymph vessels

FUNCTION ORGAN TISSUE/CELL

Shape of Cell Number of Layers

Simple (all metazoans) (one cell thick) Stratified (vertebrates only) (two or morecells thick)

1. protection

skin 1. squamous

1. linings of blood2. lings of capillaries

3. linings of lungs

flattened cells that form a continuous delicate lining permits passive diffusion of gases and tissue fluids into and

out of cavities

1. skin,2. linings of oral cavities

3. esophagus

consists of 2 or more layers of cellsadapted to withstand mild mechanicalabrasion and distortion

basal layer of cells undergoescontinuous mitotic divisions (pushedtoward surface and sloughed off andreplaced again)

2. absorption

intestine 2. columnar 1. intestine (ciliated and pseudostratified)

pseudostratified/ciliated epithelium appears to be layered but each cell touches the same

basement membranes2. female reproductive tract

cells are taller and elongated than cuboidal found on highly absorptive surfaces such as the intestinal

tract of most animals often bear minute, fingerlike projections : microvilli (increase

absorptive surface)

i. cavernous urethra

ii. pharynx

iii. nasalsurface

iv. softpalate

v. larynx

3. excre tion kidney 3. cuboida l bile duct

I. short, boxlike cellsII. usually lines small ducts and tubulesIII. may have active secretory or absorptive functions

I. specialized to accommodate greatstretching

II. urinary tract and bladder

4. secretion stomach 4. glandular

SPECIALIZATIONS IN THE STRUCTURE

Cell Junctions

- point of connection between 2 cells (allow epithelial cells to adhere to each other and exchange information & metabo

- three different types: TIGHT, ADHERENT, GAP

Occluding Junctions Location Function Characte

zonula occludens (tightjunctions)

below the free surface

of 2 adjacent cells

1. permeability barrier

2. structural barriero example: barrier to diffusion of

integral membrane proteinsbetween apical and basolateraldomains of plasmalemma

3. site of fusion of adjoining cells

membrane of adjoin

4 points

Anchoring Junctions

attach cells and theircytoskeletons to theirneighbors or theextacellular matrix

Location Function Characte

zona adherens below tight junctions

1. cohesion2. actin filament attachment sites

1. cell to cell adhere2. band-like speciali

membrane3. plaque-like dense

cytoplasm

II. macula adherens/desmosome

below zona adherens 1. intermediate filament attachment sites2. contribute to structural integrity of

epithelium as a whole by linkingcytoskeleton of adjoining cells

3. site of attachement

a. cell to cell adhereb. forms as separate

arranged in a row

III.hemidesmosome attach cell to extracellular matrix

Gap Junction/Nexus Location Function CharacteI. communicating junction for communication

MODIFIED EPITHELIAL TISSUE

Function Organ Shape of cell

transitory/tran sitional urinary bladder squamous/ cuboidal/ colu mnar

Types Based on How Products are Released

exocrine endocrine mixeda. unicellular : goblet cellb. multicellular : gastric gland ofstomach

hormones

pancreas

2. CONNECTIVE TISSUE

OVERALL CHARACTERISTICS TYPES OP CONNECTIVE TISSUE (based on the abundance and packing

1. mechanical support2. bind structures to preserve integrity of organization3. exchange of metabolites between blood and tissues4. storage of energy reserve in adipose tissues5. protection against infection6. repair7. general characteristics (structure)

a. paucity of cellsb. more intercellular substance (fibers and ground

substance)

1. binding and supporting functions2. composition:

a. few cellsb. great many extracellular fibersc. ground substance (matrix where fibers are embedded)

- plasma serves as the pathway of exchange between the cells of the body and the outside world- chief extracellular electrolytes

1. sodium chloride2. bicarbonate ions

- major intercellular electrolytes1. potassium2. magnesium3. proteins4. phosphate ions

Erhthrocyte formation1. Hemoglobin is synthesized and the precursor cell divides several times2. Nucleus shrinks during development to a small remnant and eventually disappears (exocytosis)

a. Mitochondria lostb. R ibosomes lostc. Most enzyme systems lost

3. Biconcave disc consisting of a baglike membrane packed with hemoglobin (blood-transporting pigment) is left- provides a larger surface for gas diffusion than a flat or spherical shaped cell (frogs ellipsoidal and nucleated)

Erythrocyte death1. Cell fragments and is quickly engulfed by large scavenger cells = macrophages (found in the liver, bone marrow,

spleen)2. Iron from hemoglobin is salvaged to be used again3. The rest of the heme is converted to bilirubin (bile pigment)

A. Loose Connective Tissue - fibers- fixed and wandering cellssuspended in a viscous fluidground substance

Example: Stra(dermis of skin

B. Dense Connective Tissue - composed of densely packedfibers

- fibrous tissue composedofCOLLAGEN

protein material of greattensile strength

1. Tendon (mu2. Ligament (b3. Stratum Coskin)

TYPES OF CELLS

Fixed Fibroblast/fibrocyteMesenchymal

Adipose

Fixed macrophage

Wandering (from blood) Monocyte

Lymphocyte

Plasma cell

SPECIALIZED CONNECTIVE TISSUE

VASCULAR

without fibers

composed of cellsin watery groundsubstance

BLOOD

blood ofinvertebrates

- hemolymph- closed circulatory

systems

- maintain a clearseparaionbetween bloodwithin bloodvessels and tissuefluid surroundingblood vessels

blood serum

- plasma minus theproteins involvedin clot formation

PLASMA (55 % of blood) FORMED ELEMENTS (45% of blood)

ERYTHROCYTES (RBC) PLATELETS

composed of90% water

composed of dissolved solids

composed of gases1. oxygen2. carbon dioxide3. nitrogen

1. biconcave (why?)2. for transoport of oxygen and carbon dioxide3. nucleated in fish, amphibians, reptiles, and birds4. form continuously from large nucleated

ERYTHROBLASTS in red bone marrow

1. found within the confines of blood vessels2. for blood coagulation3. no nucleus4. formed from megakaryocyte5. called thrombocyte in amphibian, reptile, and bird

i . Pro te in1. Fibrinogen

- synthesized by liver

- large proteins that functions in bloodcoagulation

2. Albumin (most abundant)

- synthesized by liver

- essential for maintaining colloid osmoticpressure of blood

- prevents loss of fluid to extracellular matrix oftissues

- transport of small molecules in the blood

- help keep plasma in osmotic equilibrium withthe cells of the body

3. Globulin

- antibodies

B.Supplies for Cells1. Glucose2. Fats3. Amino acids4. Salts

LEUKOCYTES (WBC)

GRANULOCYTE(PMN)

% of total WBC nucleus Cytoplasm (granules) Other features/fun

Ne ut rop hil 6 0-75 % 2 -5 or m or e th in l ob es con ne ct ed b yslender chromatic threads Fine and neutral pH Phagocytic

Eosinoph il 2-5% 2 ov al lobes linked by thread-likechromatin

Granules are coarse andstain pinkish-red

Against helminthic infections

Basophi l 0 .5-2% Nuc le i s ta in very faint ly , o ftenobserved by cytoplasmic granules (Uor J shaped)

Stain blue with dye Inflammatory reaction

AGRANULOCYTE % of total WBC nucleus Cytoplasm (granules) Other features/fun

Lymphocyte(SMALLEST)

20-25% Large , somehwat spher ical wi th someindentations and only slightlyconcentric position

Narrow rim of cytoplasm Antibody production

Monocyte(BIGGEST)

3-8% N ucl ei v ar y f rom s li gh tl y i nd en tedovals to horseshoe-shaped structure

Large amount ofcytoplasm

Macrophage (phagocytic)

LYMPH - Extensive network of thin-walled vessels that arise as blind-endedlymph capillaries in most tissues of the body

- Function is to return to the blood the excess fluid (lymph) filtered across capillary walls into interstitial spaces

- Similar to plasma but with lower concentration of protein

- Center for production, maintenance, and distribution of lymphocytes that produce antibodies essential components of the bodys defense mechanisms

TISSUE FLUID

ADIPOSE for storage of lipids

CARTILAGE

semi-rigid form

with closely packedfibers embedded inmatrix (gel-likeground substance)

avascular

receivenourishment

remove wastethrough matrix

TYPES OF CARTILAGE SOURCE FIBERS OTHER FEATURES

A. Hyaline

a. ventral ends of ribsb. tracheal ringsc. nose larynxd. joint surfaces

collagenous a.semi-translucentb. bluish gray color

B. Elastica. external earb. walls of auditory and Eustachian tubec. epiglottis

e las ti c a . gre at er o pac it yb. yellowish colorc. greater flexibility

C. Fibrocartilage

a. insertion of ligament and tendons intobone

b. pubic symphysisc. intervertebral discsd. joints subject to severe stress

collagenous a.most resistantb. matrix enables to it to

withstand great forces ofarticulation

BONE calcified connective tissue

contains calcium salts organized around collagen fibers (see lab reviewer for parts)

3. MUSCULAR TISSUEOVERALL CHARACTERISTICS TYPES SKELETAL CARDIAC SMOOTH

- function is for movement- structure:

1. actin2. myosin3. myocyte (muscle fiber)4. sarcolemma

- originates from mesoderm- unit: MUSCLE FIBER

- specialized for contraction- smooth muscles lack the characteristic alternating bandsof striated muscles

STRIATION striated striated Non-striated

LOCATION Attached to the skeleton Wall of heart 1. wall of digestive tube from middle of esophagus to ana2. wall of respiratory passages (trachea to alveolar ducts3. wall of blood vessel4. wall of ducts in glands5. arrectores pylorus in skin

SHAPE OF FIBER Cylindrical with blunt end Cylindrical but bifurcating (intercalcated discs) Spindle

NUCLEUS - many

- syncytial

- located in periphery of the cell

- one nucleus

- located in the center of the cell

INNERVATION - CNS : single innervations by motor nerve

- Voluntary control- ANS : double innervations by parasympathetic and sympathetic nervous system

- Involuntary

SPPED OF CONTRACTION - Rapid and powerful

- Requires frequent rest period- Intermediate

- Only rest period is between successivecontraction of heart

- Slow but with prolonged contraction

CROSS SECTION OF A SKELETAL MUSCLE

Fascicle - Packed fiber bundles enclosed by toughconnective tissue

Epimysium

Perimysium

Endomysium

Sarcoplasm - Unspecialized cytoplasm of muscles

Sarcolemma - Cell membrane

Myofibrils - Contractile elements within the muscle fiber

C.Cell Products1. Enzymes2. Hormones3. antibodies

D. Cellular Waste Products1. Urea2. Uric acid


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4. NERVOUS TISSUE

OVERALL CHARACTERISTICS NEURON GANGLION vs. NUCLEUSTYPES OF NEURON BASED ON

CELL PROCESSES

TYPES OF NEURON BASED ON

FUNCTIONS

TYPES OF CELL PROCESSES BASED

ON PRESENCE/ABSENCE OF MYELIN

SHEATH

NERVE

- Composed of several bundles of nerve

- Irritability- Conductivity

Soma Cell body 1. Unipolar

- dorsal root ganglion2. B ipolar :

- pyramidal and horizontal cellsfrom cerebral cortex, retina,olfactory membrane, ganglion ofcranial nerve

3. Multipolar

- Purkinje, and granular cells fromcerebellum, motor neuron inspinal cord

1. Sensory afferent2. Motor efferent3. Association/interneuron

1. Myelinated/medullated2. Non-myelinated/non-medullated

PART FUNCTION

Dentrites Fascicle

Axons/fiber Epineurium

Perineurium

Endonerium


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5. INTEGUMENTARY SYSTEM

- Protective wrapping

Mechanical protection against abrasion andpuncture

Effective barrier against bacteria

Moisture proofing against fluid loss or gain

Protect underlying cells against UV

- Regulatory function (temperature)

- Information getting (sensory receptors)

- Excretory function

- Respiratory function (frog, earthworm)

- Survival

- Behavioral interactions between individuals

STRUCTURE ANIMAL COLOR

INVERTEBRATE INTEGUMENT VERTEBRATE INTEGUMENT & DERIVATIVES1.Structural color colors produced by the ph

structure of the surface tissue, which refleclight wavelengths and eliminates others

2. Color due to pigments or some molecules

- Chromatophores:

Melanophores melanin (black/brow

-Group of balck/brown polymeresponsible for the various eashades that most animals wea

Xanthophores carotenoid (yellow)

Iridophores guaninine, purine (silve

a. Plasma membrane single celled organism

- pellicleb. Single layered epidermis multicellular organism

- Mollusks (Phylum Mollusca)

- Arthropods (Phylum Arthropoda)

Hypodermis, epicuticle, procuticle

Molting of arthropods (shedding of skin)

Ways by which cuticle are hardened

1.Calcification deposition of calcium carbonate in theouter layers of the procuticle (crabs and lobsters)

2.Sclerotization formation of highly-resistant andinsouluble protein (sclerotin) and happens when proteinmolecules bond together with stabilizing cross linkageswithin and between adjacent lammelae of the procuticle

Invertebrate integumentA. Epidermis and noncellular cuticle for additional

protection

B. Arthropod integument (single layeredepidermis) : hypodermis secretes two cuticle zones procuticle (thicker) and epicuticle (thinner, non-chitinous complex of proteins and lipids)

- One of the toughest materials synthesized byanimals

Basic Plana. Epidermis

- Epithelial tissue- Keratinization

- Cornified cells- Derivatives:

Hair (pelage)

Feather (pluma

Epidermal scal

Hoof

Nail

Claw

beak

Vertebrate integument and derivativesA. Epidermis

- Out stratified epithelial layer

- Derived from the ectoderm- Devoid of blood vessels- Keratinization: accumulation of keratin

- Cornified (stratum corneum)- Gives rise to most derivatives of the integument (hair, feather, hooves, etc)

B. Dermis

- Inner, thicker layer

- Derived from the mesoderm

- true skin

- Dense connective tissue layer containing blood vessels, collagenous fibers, nerves, pigment cells, fatcells, and fibroblasts (connective tissue cells)- Support, cushion, and nourish the epidermis

- Dermal derivatives: true bony structures such as heavy bony plates, scales, antlers

b. Dermis- Blood vessels

- Pigment cells- Connective tissue cells

- Nerves- Derivatives:

Fish scales

Bony plates

Fin rays

Antlers

Flat bone ofskull


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oparts:

- neural arch- neural canal

- neural spine- centrum

- pre and post zygopophyses

6. SKELETAL SYSTEMOVERALL

CHARACTERISTICSSTRUCTURE

- support- protection

- movement- mineral depot

- blood synthesis

Hydrostatic skeleton Rigid Skeleton (consist of rigid elements which are usually jointed and attached with muscles; antagonistic sets; can only contract and relax; provide movement in one direction only)Body fluid

- earthworms

Muscular hydrostat Exoskeleton Endoskeleton (formed inside the body and is composed of bone and cartilage)

1. tongue2. elephant

trunk

- lacks anyobvious form ofskeletal support,yet it is capableof bending,twisting,elongating, andlifting heavyweights

- tentacles

- they workbecause theyare composedofincompressibletissues thatremain atconstantvolume

1. invertebrate- spicules

- shells(mollusks,arthropods)

2. vertebrate

- skinderivatives

epidermalanddermalderivatives

1. invertebrate

- test, pen,dermal plates

2. vertebrates

a. main components b. parts c. appenicular d. parts of a long bone

Notochord

- Semi-rigid supportive axial rod of the protochordates and allvertebrate larvae and embryos

- Composed of large, vacuolated cells

- Surrounded by layers or elastic and fibrous sheaths

- Stiffening device- Preserves body shape during locomotion

- Surrounded/replaced by the backbone during embryonicdevelopment

Cartilage

bone

cartilage + bone

axial

- cranium/skull

- notochord

- vertebral columno types:

-cervical (7) - neck

-thoracic (12) - chest

-lumbar (5) - back

- sacral (5: fused) - pelvic- Caudal (about 4: coccyx)

ribs

sternum

girdles (where limbbones areattached) : pectoral& pelvic

skeleton of pairedfins or limbs (wings)

skeleton of medianfins (fish)

Periosteum Active connective tissue

Spongy bones Loose areas

Compact bones Haversian canals

Endosteum Squamous epithelium

Bone marrow

Diaphysis Middle part, primary ossicenter

Epiphyseal plateCartilaginous space betwepiphysis and diaphysis

Epiphysis

Articularcartilage

Outer part of the epiphys

e. stages of bone formation f. growth and ossification of bone g. joints

1. Mesenchymal

- lose reticulate cell Growth hormones / Bones Synarthoses/immovablejoints

2. Cartilage Somatotrophin - growth hormoe

- stimulate the osteoblast (rapidly dividing cells)Diarthoses/freely movablejoints

Pivotal/rotaryGlidingBall-and-sockeHinge joint

3. Bone1.Develops from cartilage (endochondral)

2. Embryonic cartilage is eroded bone forming cells (replacement bone)begin depositing calcium salts around strandlike remnants of the cartilage

3.Intramembranous bone develops directly from shets of embryonic cells(dermal bone; face bones, cranium, clavicle)

4.Cancellous bone (spongy bone) consists of an open interlacingframework of bony tissue oriented to give maximum strength undernormal stresses and strains that the bone receives

all bone develops as cancellous bone (but some become compact uponfurther deposition)

Calcitonin - From the thyroid gland- Inhibits bone resorption

- together with vitamin D, these maintain a constantlevel of calcium in the blood

Parathormone/parathyroidhormone

- parathyroid hormone which stimulates boneresorption

- together with vitamin D, these maintain a constantlevel of calcium in the blood

Amphiarthoses

Cartilage stage already (starting point)

- Diaphysis : primary ossification center

- Secondary center : ephiphysis (ephiphysal plate cartilaginous : as long as theplate is present, the bone will grow)

Osteocyte - mature bone cells

Osteoblast Growing bones

Osteoclast Responsible for making the bone hollow

7. LOCOMOTORY SYSTEM

FUNCTION TYPES OF MOVEMENT

1. For movement2. Allows organism to move from one

place to another3. Allows organism to obtain food

Ciliary Muscles

1.Protozoa Origins of skeletal muscle Sequence of events involved in contraction and relaxation of skeletal mus2. Ciliated cells 1. Muscle I. Structures in volved

3. Cilium/flagellum 2. Muscle fiber II. Steps in contraction

STRUCTURE a. Axoneme (9+2arrangement)

3. Sacromeres - Functional unit of the myofibril

- Z line : dense structure that holds thin filaments together

1. Discharge of motor neuron2. Release of transmitter (acetylcholine) at motor-end plate3. Binding of transmitter to receptor

4. Increased permeability of end-plate membrane to Na + and K+5. Generation of endplate potential6. Generation of action potential in muscle fibers7. Inwards spread of depolarization along T tubules

- System of tubules found along the surface of the sarcolemm(invaginations)

- See myoneural junction and sarcoplasmic reticulum8. Release of Ca from lateral sacs of sacroplasmic reticulum and diffusion

thin filaments

9. Binding of Ca+2 to troponin C, uncovering myosin binding sites on actin10. Formation of cross-linkages between actin and myosin

Cilia - Minute, hairlike, motileprocesses that extendfrom the surfaces of cellsof many animals

-Tubulin

- Protein dynein

i. Dynein

- ATP are motorproteins attached tomicrotubules

5. Thick filament (myosin)

i ii . Radia l spokes 6. Sarcolemma

iv. Nexin 7. Sarcoplasmic reticulum - System of fluid-filled channels that runs p arallel to the myofilaments

- Speeds up depolarization from the myoneural junction to the myofilaments within the fiber

v. Sheath projections 8. Fascicle

b. Kinetosome/blepharoplast/basal body/basal granule

9. Myofibrils - Contractile elements within the muscle fiber

c. Microtubules 10. Myofilaments

i. Tubulin (proteinsubunits)

11. Thin filaments(actin, tropomyosin,troponin :: contractileelements)

- Tropomyosin: two thin strands of protein that lie between actin strands

- Troponin : located at intervals along the filament that is calcium-dependent and acts as thecontrol point in the contraction process

Locomotion in some organisms

Flagella - Whip-like structurelonger than a cilium andusually present singly orin small numbers at oneend of a cell

- Different from a cilium:beats symmetrically withsnake-like undulations sothat water is propelledparallel to the long axisof the flagellum

1. Planaria 13. Sarcoplasm - Unspecialized cytoplasm of muscles III. Steps in relaxation

2. Sna il 14. T tubules - Numerous invaginations that project as a system of tubules into the muscle fiber

- Arranged for speeding the electrical depolarization from the myoneural junction to themyofilaments within the fiber

1. Ca2+ pumped back in sacroplasmic reticulum2. Release of calcium from troponin3. Cessation of interaction between actin and myosin

3. Earthworm

4. Vertebrate

AmoeboidSliding filament hypothesis Other concepts

Control of muscle contraction- Muscle contracts in response to nerve stimulation

- If the nerve supply to a muscle is severed, the muscle atrophies or wastes away

- Motor unit : motor neuron and all muscle fibers it innervates (functional unit of a skeletal m

- Motor unit recruitment: happens when a smooth and steady increase in muscle tension isby increasing the number of motor un its brought into play

Myoneural junction

- Place where a motor axon terminates on a muscle fiber

- Synaptic cleft : tiny gap that thinly separates a never fiber and muscle fiber Acetylcholine in synaptic vesicles

Released when a nerve impulse reaches a synapse

A chemical mediator that diffuses across the narrow junction and acts on the muscle fiber memgenerate an electrical depolarization = contraction

1. Protozoa

2. Pseudopodia (falsefeet)

- Used to explain striated muscle contraction1. Thick and thin filaments become linkedtogether by molecular cross bridges, which act as

levers to pull the filaments past each other2. During contraction, cross bridges on thethick filaments swing rapidly back and forth,alternately attaching to and releasing fromspecial receptor sites on the thin filaments anddrawing thin filaments past thick in a kind ofratchet action3. Z-l ines pulled closer together4 . S ac ro me re sh or te ns5. Muscle contracts

Relaxing requires the force supplied by theantagonistic muscles or forced gravity

1. Muscle twitch2. Stair case/treppe3. Muscle trophy and hypertrophy

4. Tetanus5. Muscle tonus3. MicrofilamentsPseudopodia

- False feet 4. White blood cells

Muscle - Fibers (highly developedmuscle cells)


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8. DIGESTIVE SYSTEM 9. RESPIRATORY SYSTEM


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TYPES OF ORGANISMS AS TO HOW THEY OBTAIN

THEIR ENERGY OR NUTRITIONORGANIZATION OF THE ALIMENTARY CANAL

1. Autotrophsa. Phototrophsb. Chemotrophs gain energy from inorganic

chemical reactions2. Heterotrophs

Reception (mouth)- First region of the alimentary canal consists of devicesfor feeding and swallowing

- Swallowing begins with the tongue pushing moistenedfood toward the pharynx

Conduction

Terminal digestion & Absorption 1. Herbivores have suppressed canines but well developewith enamel ridges for grinding

2. Rodents have well developed, self-sharpening incisorsthroughout their life and must be worn away by gnawing to keegrowth

3. Elephants tusk is a modified upper incisor used for deattack, and rooting

Digestion (carrying asunder)

- Organic foods are mechanically and chemically broken down inunits for absorption

A. Action of digestive enzymes

- Reduction of foods to small, absorbable units relies prichemical breakdown by enzymes

- Digestive enzymes are hydrolytic enzymes (hydrolase

- Hydrolalses = food is split by the process of hydrolysis

B. Motility in the alimentary canal

1.Food is moved through the digestive tract by cilia or bymusculature

- Movement by cilia in the aceolomate andpseudocoelomate metazoan that lack mesodermamusculature of true coleomates

- Cilia move intesti nal fluids

2.Most characteristic of the gut movement : segmentat/MOTILITY IN THE ALIMENTARY CANAL

- Alternate constriction of rings of smooth mintestine that constantly divide and squeeze the cback and forth- Serves to mix food but does not move it thgut

3. Peristalsis : sweeps the food down the gut with wavescontraction of circular muscle

Organization and regional function of the alimentary canalA. Receiving Region: mouthpartsB. Conduction and storage region

C. Region of grinding and early digestion

- Cellulase: the only enzyme capable of breaking down thecellulose that encloses the plant

D. Region of terminal digestion and absorption: The intestineE. Digestion in the vertebrate small intestine

1. Pyloric sphincter2. Duodenum

- Essential change in pH of chime because all intestinal eeffective only in a neutral or slightly alkaline medium

F. Absorption

- Little food is absorbed in the stomach because digestioincomplete and because of limited surface area- Most digested food is absorbed from the small intestine

- Intestine is impermeable to polysaccharides (carbohydabsorbed as simple sugars)

- Proteins are absorbed principally

- Absorbed food, etc are diffused into the blood (lowerconcentration)

Hormones that regulate digestion

- Leptin : tells the hypothalamus how much fat the body carlevels, release of leptin by fat cells leads to diminished appetiteincreased thermogenesis)

- Gastrin: produced by endocrine cells in the pyloric portiostomach which stimulates HCl secretion and increase gastric m

- CCK (cholecystokinin): secreted in the walls of the small iwhich:

1. stimulates gallbladder contraction and increases flow othe intestine2. stimulates an enzyme-rich secretion from the pancrea3. acts on the brain to contribute a feeling of satiety afte

- secretin : produced in the duodenal wall and secreted ito food and strong acid in the stomach (stimulate the release opancreatic fluid that neutralizes stomach acid as it enters the i

I. Structure- Long, coiled to increase surface length

- Inward folding increase inner surfacearea for more absorption

FEEDING MECHANISMS 1. Sma ll intestine

a. Suspension feeder (worms)

-Most important and widely employed methods forfeeding

-Use ciliated surfaces to produce currents that drawdrifting food particles into their mouths

b. Substrate feeder

-Remove whatever provides nourishment from thefood (annelids)

c. Fluid feeder-Absorb nutrients surrounding them

-Used by parasites (ecto and endo), mosquitoesd. Bulk feeder

Types of teeth (mammals are the only onescapable of true mastication)

a. Incisors for biting, cutting, and strippingb. Canines for seizing, piercing, and tearing

Premolars - for grinding and crushing (back of the jaw)d. Molars for grinding and crushing (back of the jaw)

a. Buccalcavity

a. Esophagus

- Peristaltic contraction ofesophageal muscles forcesfood smoothly toward thestomach

- Serves to transfer food tothe digestive region

b. Crop

- used for food storage beforedigestion

- annelids, insects, octopods,birds

- serves to store and softenfood before it passes to the

stomach

Duodenum -The intestinal end where churning ismost vigorous

- First region of the small intestine

- Where food is steadily releasedb. Teeth

c. Pharynx-As food slides down the pharynx,

the epiglottis tips down over thetrachea, nearly closing it

d. Tongue - Attached to the floor of themouth- Assists in food manipulation

b. Jejunum

Ileum

2. Villi - Increase internal surface area

- Facilitates greater absorption

- Minute finger-like projections inside theintestines

- Gives the intestine a velvet-like feeling

g. Bolus - Food mass

h. Salivarygland

- Buccal glands that producelubricating secretions containing

mucus to assist swallowing

-salivary amylase : carbohyd rate-splitting enzyme that beginshydrolysis of plant and animalstarches (inactivated by the acidicenvironment of the stomach)

-does not completely hydrolyzefood = MALTOSE (2 glucosefragments)

5 . Mi cro vil li - Delicate processes that border each cellof the lining of the intestinal cavity

- Increase

- Facilitates internal surface area- Facilitates greater absorption

6. Valve of Kerkring

7. Typhlosole o f oligochaete

- Inward folding of dorsal intestinal wallsof of worms

- Effectively increases internal surfacearea of the gut in a narrow body lackingspace for a coiled intestine

TYPES OF HETEROTROPHS BASED ON DIETARY

HABITS1. Herbivorous2. Carnivorous3. Omnivorous

Grinding & Early digestion

I. Structure II. Secretions intoduodenum

TYPES OF DIGESTIONa. Intracellular

- Food particle is enclosed within a food vacuole byphagocytosis

1. Digestive enzymes are added and theproducts of digestion (simple sugars, aminoacids, and other molecules) are absorbed intothe cell cytoplasm where they may be used

directly or (in multicellular animals) betransferred to other cells

2. Food wastes are simply extruded from thecell

- Limitations:1. Only particles small enough to be

phagocytized can be accepted2. Every cell must be capable of secreting

all of the necessary enzymes3. Every cell must be capable of absorbing

the products into the cytoplasmb. Extracellular (most arthropods and vertebrates)

- Where digestion of large food masses could takeplace

-Certain cells lining the lumen of the alimentary canalspecialize in forming various digestive secretions,whereas other function largely in absorption

-With increased regional specialization of thedigestive tract

1. Stomach of ruminant

1. Pancreatic juice

a. Rumen a. Bicarbonate - High bicarbonate content of pancreaticjuice and bile

- Neutralized the acidic pH of fooddigestied

b. Omasum

c. Rennin - milk curdling enzyme found in the stomach

- used in making cheeseb. Pancreatic

enzymes

e. Reticulum i. Trypsinii. Chymotrypsin

- Both continue the enzymatic digestion ofproteins begun by pepsin, which is nowactivated by the alkalinity of theintestine

- Split apart peptide bonds deep insidethe protein molecule

- Powerful protease

f. Absomasum

2. Gizzard - Muscular structure- Hardened parts that assist in digesting harder food

3. Digestivediverticula

- blind tubules or pouches arising from the main passage linedwith a multipurpose epithelium having cells specialized forsecreting mucus, digestive enzymes, or absorption or storage(invertebrates) iv. Carboxypeptid

ase- Removes amino acids from carboxylends of polypeptides4. Stomach - Provides initial digestion as well as storage and mixing of foods

with digestive juices

- U-shaped muscular tube provided with glands thatproduce proteolytic enzymes and strong acids

v. Pancreaticlipase

- Hydrolyzes fat into fatty acids andglycerol

vi. Pancreaticamylase

- Starch splitting enzyme identical tosalivary amylase in its action

a. Cardiacsphincter - Opens reflexively to allow food to enter then closes to

prevent regurgitation back into the esophagus (as food entersthe stomach)

vii. Nucleases - Degrade RNA and DNA to nucleotides

NUTRITIONAL REQUIREMENTS-Vitamin is a relatively simple organic compound thatis not a carbohydrate, fat, protein, mineral; required

in very small amounts in the diet for some specificcellular function

- Essential nutrients : needed for normalgrowth and maintenance and that must be suppliedin the diet

c. Pyloricsphincter

- Regulates the flow of food into the intestine and preventsregurgitation in the stomach

- Deep tubular glands in the stomach secrete gastricjuice

- Relaxes at intervals to allow entry of acidic stomachcontents into the initial segment of t he small intestine(duodenum)

- 2 secretions: BILE and PANCREATIC JUICE (high bicarbonatecontent)

2. Bile - Secreted by the liver in the bile duct

- Drained into the upper intestine

(duodenum)

- Collects in the gallbladder (storagesac that releases bile when stimulatedby the presence of fatty food in theduodenum)

TYPES OF DIGESTIVE SYSTEM

a. Completeb. Incomplete

ACTION OF DIGESTION ENZYMES f. Rugae a. No enzyme - Since fats are resistant to enzymaticdigestion

R-R + H2O digestive enzyme R-OH + H-R(food molecule)(products)

g. Types of cells: b. Bile salts (mainlysodiumtaurocholate andsodiumglycocholate)

- Essential for digestion of fats

- Reduce surface tension of fat globules(large, water-insoluble)

- Allows the churning action of intestineto break fats into tiny droplets(emulsification)

i. Chief cells (pepsin) - Secrete pepsin (a protease : protein splitting enzyme) that actsonly in an acidic medium

- Splits large proteins by preferentially breaking down certainpeptide bonds scattered along the peptide chain of proteinmolecules

REGULATION OF FOOD INTAKE

- Hun er center re ulates intake of food

TYPES OF RESPIRATION VENTILATION - respiratory medium and structure (increase frequency of contact) GASEOUS EXCHANGE IN1. Direct/cutaneous Rhythmic body

movementsWater current Breathing Use of air sacs Laws of physical diffusion (high to l ow

- Partial pressure of oxygen in lung ait is in v enous blood of lung capillainto the lung capillaries

- Carbon dioxide in blood of the lunghigher concentration than has this alveoli = carbon dioxide diffuses falveoli

2. Indirect 1. Paddle-likeappendages

2. Coordinatedmovements of jawsand operculum

3. Countercurrentexchange

4. Oppositemovement of bloodin capillaries(oxygen towardsthe blood vessel)

1. Positive pressure breathing (frog) Action to force air into lungs Parabronchi

- Birds

- Air sacs that serve as air reservoirs duringventilation

- Where gas exchange takes place (25%)

- Remaining air bypasses the lungs to enterthe air sacs (gas exchange does not occurhere)

- Receive nearly fresh air during inspirationand expiration

2 stages (energy from food isreleased by oxidativeprocesses usually withmolecular oxygen as theterminal electron acceptor ::with oxygen taken across arespiratory process)

a. External respiration(from environment to RBC :exchange of carbon dioxide andoxygen between the organism andenvironment)

b. Internal respiration(RBC to epithelial cells)

2. Negative pressure breathing(humans)

Air is pulled into the lungs by expansion of the thoracic cavity

a. I nt er cost al mus cl es

b. Diaphragm

c. Inspiration Pulls ribs upward, flattens the diaphragm, and enlarges the chestcavityCauses air pressure in lungs to fall below atmospheric pressure

d. Expiration Less active process than inspirationMuscles relax, diaphragm return to original position, chest cavitydecreases in size, elastic lungs deflate, air exits

Partial pressure of gas due to the mixture of gases (71%

oxygen) Partial pressure of oxygen in bloo

in the blood Gases diffuse from a location of h

one of lower concentration

a. PO2 = 760 mm Hg x 20.96

b. PCO2 = 760 mm Hg x 0.04

e . T id al v ol um e = 5 00 m L

f.Vital capacity = 3400 mL or4800 mL

g. Residual volu me

h . T ot al l un g ca pac it y

RESPIRATORY MEDIUM RESPIRATORY PIGMENT AND TRANSPORT OF OXYGEN RESPIRATORY ORGANS/ RESPIRATORY

STRUCTURESA. Gas exchange by dried diffusion (plasmamembrane, integument)

1. Cutaneous respiration direct diffusion ofgases

- Worms, sponges, protozoa2. Eel vascular skin

B. Gas exchange through tubes : trachealsystems

1. Use of branching systems of tubes (trachea)that extends to all parts of the body

a. Tracheoles : end channelsb. Spiracles: where air enters in the tracheal

system

- Valve like openings- Where carbon dioxide diffuses out

2. Insects respiration is independent of itscirculatory system (no direct role in oxygentransport)

C. Efficient exchange in water: Gil ls1. Examples:

a. External surfacesb. Dermal papulae sea starsc. Brsnchial tufts marine wormsd. Internal gills fish

o Countercurrent flow

provides greatest possible extractionof oxygen from water

Water flows over the gills in a steadystream, pulled and pushed by anefficient, 2-valved, branchial pump

Gill ventilation is often assisted bythe fishs forward movement throughthe water (ram ventilation)

D. Lungs

MAMMALS1. Alveoli

- Large surface area essential for the highoxygen uptake required to support theelevated metabolic rate of endothermicmammals

- Many capillaries2. Disadvantages

- Gas is exchanged between blood and aironly in the alveoli (located in at the ends of abranching tree of air tubes trachea, bronchi,and bronchioles)

- Air must enter and exit through the samechannel

- After exhalation : air tubes are filled withused air from the alveoli which, during thefollowing inhalation is pulled back into thelungs

- Volume of air in a lungs passageways :DEAD SPACE

- Lung ventilation is so inefficient : in normalbreathing only 1/6 of the air in the lungs isreplenished with each inspiration

STRUCTURE AND FUNCTION OF THE MAMMALIAN RESPIRATORY SYSTEM

1. Air enters the respiratory system through nostrils (external nares)

2. Air passes through a nasal chamber (lined with mucus-secreting epitheliu

3. Air then passes through the internal nares : nasal openings connected to

- Inhaled air leaves the pharynx by passing into a narrow opening : glottis

- Food enters the esophagus to pass to the stomach

4. Glottis opens to the larynx (voice box) and then to the trachea (wind pipe

5. Trachea branches into two bronchi

6. Within the lungs each bronchus divides and sub divides into small tubes (bvia alveolar ducts to the air sacs (alveoli)

- Single-layered endothelial walls of the alveoli and alveolar ducts are thin exchange of gases between air sacs and adjacent blood capillaries

- Lined with mucus-secreting and ciliated epithelial cells- Partial cartilage rings in the walls of the trachea, bronchi, and even some

prevent structures from collapsing

7. THE PARTS OF THE LUNGS:a. Elastic connective tissue and some muscle

b.Covered by a thin layer of tough epithelium visceral pleura

c.Parietal pleura lines the inner surface of the walls of the chesto Two layers of the pleura are in contact and slide over one another as

contract

d.Pleural cavity space between the pleura maintains a partial vacuumlungs expanded to fill the pleural cavity

e.the chest cavity is bounded by the spine, ribs, and breastbone, and floo: dome-shaped, muscular partition between the chest cavity and abdom

f.muscular abdome n found only in mammals

A. VENTILATING THE LUNGS

- Chest cavity is an air-tight chamber

B. HOW BREATHING IS COORDINATED1. Composition of air changes as soon as it enters the respiratory tract2. Inspired air becomes saturated with water vapor as it travels through air-fille

toward the alveoli

3. Air mixes with residual air remaining from the previous respiratory cycle4. Partial pressure of oxygen drops and that of carbon dioxide rises5. Upon expiration, air from the alveoli mixes with the air in the dead space to

mixture

-Although no significant gas exchange takes place in the dead space, air itair to leave the body when expiration begins

C. GASEOUS EXCHANGE IN LUNGS & BODY TISSUES: DIFFUSION AND PARTIAD. HOW RESPIRATORY GASES ARE TRANSPORTED

- Respiratory pigments in the blood transport carbon dioxide

- For hemoglobin to of value to the body it must hold oxygen in a loose, revcombination so that it can be released to tissues

a.Hemoglobin binds oxygen: when oxygen concentration is high (capillaries and lung alb.Hemoglobin releases its stored oxygen reserves: when oxygen partial pressure is low

- Solubility of oxygen inplasma is so low that plasmaalone cannot carry enoughoxygen to support metabolicprocesses

- Needs hemoglobin

Hemocyanin Blue, copper-containg protein, occurs in crustaceans and mollusks

Hemoglobin Most widespread respiratory pigmentRed-iron-containing protein present in all vertebrates and many invertebrates

Heme 5% heme (iron-containing compound giving the red color to the bloodGreat affinity for oxygen)

CHARACTERISTIC OF

RESPIRATORY STRUCTURES

Globin 95% globin (colorless protein)

1. Highly vascularized internalcavities

2. Thin walled for exchangeof gases

3. Wet so oxygen can move

Oxyhemoglobin - Hemoglobin with bound oxygen- Its sensitivity to carbon dioxide affects the conformation of hemoglobin and

therefore its release of oxygen to tissues

Carboxyhemoglobin

- Carbon monoxide

Dissociation curve - Oxygen dissociation curve- Hemoglobin saturation curves

-The lower the surrounding oxygen tension, the greater the quantity if oxygenreleased

- Allows more oxygen to be released to those tissues which need it most (those withthe lowest partial pressure of oxygen)

Bohr shift - Carbon dioxide shifts the hemoglobin saturation curve to the right

- As carbon dioxide enters the blood from respiring tissues, it causes hemoglobin tounload more oxygen

- Opposite event occurs in the lungs = as carbon dioxide diffuses from venous bloodinto alveolar space, the hemoglobin saturation curve shifts back to the left allowingmore oxygen to be loaded onto hemoglobin

CONTROL OF BREATHING

Medullaoblongata

- Neurons in the medulla of the brain regulate normal. Quiet breathing

- Neurons spontaneously produce rhythmical bursts that stimulate contraction of the diaphragm and externalintercostals muscles

Pons

CO2 + H2O H2CO3 HCO3- + H+

- Carbonic acid is created

- Carbonic acid then dissociates to release hydrogen ions, making the cerebrospinal fluid more acidic, and stimulating respiratoryreceptors in the medulla of the brain

- Carbonic anhydrase: water-carbonate part

Phrenic nerves

Intercostalnerves

3 IMPORTANT CHANGES IN AIR DURING ITS PASSAGE TO AIR SACS

a. It is filtered free from most dust and other foreign substancesb. Warmed by body temperaturec. Saturated with moisture

COMPOSITION OF INSPIRES, EXPIRED & ALVEOLAR PAIRS

I nsp ir ed a ir ( vol %) Ex pir ed a ir ( vol %) A lv eol ar a ir ( vol %)

Oxygen 20.96 16 14Carbon dioxide 0.04 4 5.5

nitrogen 79 80 80.5

TRANSPORT OF CARBON DIOXIDE

1. 67% bicarbonate ion (plasma and RBC water)2. 25% combined with hemoglobin (carbaminohemoglobin)3. 8% physically dissolved CO2 in plasma and RBC

PROBLEMS OF AQUATIC AND AERIAL BREATHING- Respiratory surfaces must be thin

- Respiratory surfaces must always be kept wet with a fine film of fluid to allow diffusion of gases across an aqueous phase betweenthe environment and the underlying circulation

9. Evaginations - gi lls10. Invaginations lungs and trachea (pumping mechanisms to move air in and out of the body)

FROG RESPIRATION1. Ventilate lun s b first drawin air into the mouth throu h the external nares (nostrils)

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Zoology 3rd Exam