BIO 3 Handout

8/7/2019 BIO 3 Handout

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BIO 3 HANDOUT

ANIMAL TISSUES

A.Epithelial tissues-lining of the surfaces-selectively permeable-regenerates (in liver andstomach the tissues are replacedevery 2-3 days)-simple epithelial cells(squamous, cuboidal, columnar)

Cheek squamous epithelial cells

Collecting ducts in the medulla

of a mammalian kidney linedwith simple cuboidal cells

Intestinal columnar cells

B.Vascular tissues

BLOOD -circulates throughout the body-carries nutrients and oxygen or

wastes-made up of different

components:

Plasma-water-containing

fluid

Platelets (thrombocytes)-function for blood clotting

White blood cells(leukocytes)- hasdifferent types(neutrophil, basophil andeosinophil) ; function forimmune response


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Neutrophil- against bacteria;inflammatory reactions

Basophil- responsible for allergic

reactions

Eosinophil- responsible for immune

response against parasites

Red Blood Cells(erythrocytes)- withhemoglobin; carrier ofoxygen

Enucleated human RBCs

Lymph (lymphocytes: T

cells and B cells) for theimmune system

T cell (blue)- attack foreign

bodies as a principal mean ofdefense

B cell (arrow)- responsible for

the production of antibodiesCONNECTIVE TISSUE PROPER -with abundant matrix(extracellular materials)

-Adipose cells/ fat cells/adipocytes

important for nutrientstorage

found under the skin,bone marrow, around the

kidneys, hips and breastswithin the cells are fat

droplets (triglycerides)

incapable of dividing(increase in body weight-cells swell)

-Tendon (muscle to bone) andLigament (bone to bone)

Adipose cells


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CARTILAGE -cells: chondrocytes within thelacuna

-composed of glycoproteins:chondroitin and collagen fibers

-high tensile strength-found at (joints) surfaces ofbones

-tip of nose, pinna (ear), larynxor voice box

Chondrocytes

BONE -calcified cartilage (calciumphosphate)

-cells: osteocytes

Haversian system (bracket);Canaliculi (arrow)MUSCLE TISSUESmooth Muscle

-location: walls of blood vessels,stomach, intestines

-function: powers rhythmicinvoluntary contractions

Skeletal Muscle -location: voluntary muscles

-function: powers walking, lifting,dancing

Cardiac Muscle -location:walls of the heart

-highly interconnected cells

promote rapid spread of signalinitiating contraction

NERVE TISSUENeurons

-capable of electrochemicalevents: IMPULSES

-parts:


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Cross section of a nerve

THE GENERAL BODY PLAN OF

ANIMALS

-Kingdom animalia is the most diversegroup of organisms. One of thereasons is the differences in thegeneral body plan. Throughout theevolution of animals, their body planshave undergone many changes:Evolution of Tissues

-simplest animals like Parazoas(sponges) exist as simply aggregates

of cells with minimal intercellularcoordination.

-eumetazoa (all higher animals),

have distinct tissues with highlyspecialized cells.

Evolution of Bilateral Symmetry -sponges lack symmetry

-RADIAL symmetry- exhibited bymarine animals: Cnidarians(jellyfishes, sea anemones and corals)and Ctenophorans (combjellies).

Jellyfish sea an

Corals

-BILATERAL symmetry- right and

left mirror images; concept ofdorsal/ventral, anterior end/posterior end; allowed animals to:

-move more efficiently-have different organs

located in different partsof the body-produce 3 germ layers:ectoderm-outer coverings,mesoderm-skeleton andmuscles, and endoderm-digestive organs-cephalization

Evolution of Body Cavity


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-evolved for supporting organs, anddistributing materials- 3 kinds of body plans:Acoelomates

-no body cavity-flatworms: tapeworms, flukesand planarians

Tapeworm Liver Fluke

Planarian

Pseudocoelomates

-with a body cavity- pseudocoel-between mesoderm and

endoderm-nematodes: Ascaris

Evolution of Segmentation- subdivision of the body into

segments-advantages: (annelids) damage in

one segment is not fatal(duplication of segmentfunctions)

and in locomotion, each segmentcan move independently.

-SegmentationMETAMERISM: eachsegment is similar to the other(somites/metameres).

TAGMATIZATION:segments fused into functionalgroups (tagmata)

clitellum Pheretima (earthworm)

Linkia (starfish)

Penaeus (shrimp)


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Periplaneta Americana

Bufomarinus

ORGAN SYSTEMS

THE PROTECTIVE AND

SUPPORT SYSTEMS OF

ANIMALS

Main functions: to provide support,protection and enable movement ofdifferent skeletal forms:

Hydrostatic Skeleton -exhibited by mollusks andnematodes/ worms

-pressurized fluid incompartments and by using themuscles surrounding thesecompartments, the animal changes

shape and produces movement(peristaltic movement - squeezingother segments while allowing othersto relax)

Exoskeleton -skeletons which encases theorganisms body

-exhibited by insects,crustaceans and spiders

-composed of CHITIN (light,strong for protection and reduction of

water loss);-can be calcified for further

strengthening


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Euplectella(Venus basket) the skeleton is made up of silica

Endoskeleton -found within the body of the animal

-vertebrates (bones) and echinoderms (ossicles) calcium rich-2 sections: axial skeleton and appendicular skeleton

DIGESTIVE SYSTEM


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Types of Digestive Tracts (Guts)Incomplete Gut

-single opening: mouth

-Planarian, Cnidarian,

Nematodes-gastrovascular cavity: mouth,pharynx, intestine

-extracellular digestion:circulation of food by diffusion

-no specialization of partsComplete Gut -two openings: mouth and anus

-with specialization of parts:

pharynx-draws in food with asucking action

gizzard- thick muscular walls forchurning and grinding of food

cloaca- storage of undigestedmaterials, urine, and products ofthe reproductive system

cecum- with bacteria; aids thedigestion of cellulose; located atthe beginning of the largeintestine; more prominent inruminants/ herbivores

accessory organs:-liverproduces bile (greensolution that emulsifies fats)-gall bladderstores andconcentrates bile-pancreas release digestiveenzymes and bicarbonate buffersto aid digestion


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EXCRETORY SYSTEM

Planaria/ Flat worms -PROTONEPHRIDIA (tubules)which branchout into bulb-like FLAME

CELLS -cilia within the flame cells drawin fluids from the body

-the wastes are expelled throughexcretory pores that open outside thebodyAnnelida/ Round worms -NEPHRIDIA (tubules) obtain fluidfrom body cavity by filtration ofNEPHROSTOMES- pore for urine

excretion (urine is diluted; NaCl isreabsorbed)-in Mollusks (kidney) and

Crustaceans (antennal glands)- urineproduced from filtration; ions arereclaimed by reabsorptionInsects -MALPHIGIAN TUBULES whichbranch off anterior to the hindgut

-waste products and potassium

ions are secreted into tubules by activetransport-most water and K+ are

reabsorbed; dry waste productexcreted from the rectumVertebrates -kidneyNEPHRONSNITROGENOUS WASTES:Ammonia- can be toxic to cells;

released in a diluted form by bonyfishes and tadpolesUrea- excreted by adult amphibians,mammals; soluble in water and can beexcreted in large amounts; frombloodstream to liver, then kidneys andexcreted as urine

Uric acid- from reptiles, birds andinsects; slightly soluble in water; insolid form, excreted with little water(helps in reduction of water loss)

In most mammals, there is an enzyme:URICASE which convert uric acid toallantoin, a less toxic substance, buthumans, apes, and Dalmatian dogs donot have it. The excessive deposits ofuric acid can cause: Gout.

CIRCULATORY SYSTEM

3 principal functions of C.S.:

Transportation nutrients and oxygenRegulation transport of regulatoryhormonesProtection blood clotting and immunedefenseTypes of Circulatory SystemsFor Cnidarians, Flatworms/ Planarianswhich have two layers of body wall,have direct contact with the external

environment that transport can occurby diffusion.Open Circulatory System

-exhibited by mollusks andarthropods

-no distinction between thecirculating fluid (blood) andextracellular fluid (interstitialfluid/lymph): HEMOLYMPH

-heart is a muscular tube which

pumps hemolymph through a networkof channels and cavities in the body-fluid drains back to the central

cavity


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Closed Circulatory System -exhibited by annelids(invertebrates) and all vertebrates

-circulating fluid (blood) isenclosed in blood vessels

a-artery(away from the heart); b-capillary; c-vein (back to the heart)

Earthworm-dorsal vessel contracts to

function as pump-blood is pumped through 5 small

connecting arteries which function aspumps to a ventral vessel (transportposteriorly until it re-enters dorsalvessel

Fishes-have true chamber-pump heart: sinusvenosus and atrium (collection chambers);ventricle and conus arteriosus(pumpingchambers)

Toad heart has three chambers: rightand left atria, and a ventricle.Amphibian and Reptile Circulation2 types:Pulmonary Circulation

-heart to lungs, then back to heart-pulmonary artery-lungs-pulmonary

vein-heartSystemic Circulation

-heart to body organs, then back toheart


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Mammalian and bird hearts are four-chambered.

RESPIRATORY SYSTEM

Fishes have gills wherein water passes from the gill arch and over the filaments.Water always passes the lamellae in an opposite direction of blood flow. The successof the gills operation is dependent on the countercurrent flow of blood and water.


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In amphibian lungs, each lung is an outpouching of the gut. It is filled with air by thecreation of a positive pressure inside the buccal cavity. Their lungs are not asefficient as the lungs of other terrestrial vertebrates because they lack structuresthat would increase the surface area of the lungs for gas exchange.

NERVOUS SYSTEM

Evolution of the Nervous System. Animals exhibit a progressive elaboration of organized nerve cordsand the centralization of complete responses in the front end of the nerve cord. This evolutionaryprocess is known as CEPHALIZATION.


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Evolution of Vertebrate Brain. In sharksand other fishes, the hindbrain is predominant,which primarily is used to process sensory

information. For amphibians and reptiles, theforebrain is more dominant as the cerebrumbecomes bigger. It is devoted to associativeactivity. In birds and mammals, especiallyhumans, the largest portion of the brain is thecerebrum.

Reflex Action

ENDOCRINE SYSTEM

An adult insect emerging from an old cuticle

Insects exoskeleton cannot expand as theorganism grows, this is the reason they undergomolting. This process is initiated to occurbecause of hormones released by endocrineglands.

References:Raven et. al. 2005. BIOLOGY. 7th ed.

McGraw Hill Company. Boston.

Mader S.S. 1998. BIOLOGY. 6th ed.

McGraw Hill Company. Boston. Pp

716-912.


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Anatomy of Planarians

ANIMAL REPRODUCTION

-all animals have a DIPLONTIC life cycle,the only haploid cells are the SEX CELLSor GAMETES-reproduction is very essential for thesurvival of species and the creation ofdiversity (variation).2 types:ASEXUAL REPRODUCTION -involves 1 parent (samegenotype: no variation)

-exhibited by:

FlatwormsTRANSVERSEFISSION

CnidariansBUDDING fromparent

Echinodermscut to form newindividuals

InsectsPARTHENOGENESIS(females produce offspringsfrom unfertilized eggs

Some fishesSEQUENTIALHERMAPHRODISM (protogyny-female at first, then change toa male; protoandry- male thenbecomes a female)

SEXUAL REPRODUCTION

-fusion of two gametes-variation is achieved: exchange

of genetic content2 types of FertilizationEXTERNAL FERTILIZATION -many gametes released in water

-animal sperm must swim to eggsINTERNAL FERTILIZATION -for animals that lay shelledeggs/ have a period of internal

embryonic development-for terrestrial animals which

can enable their sperm to swim withoutdrying out

-males have special organs usedfor transferring sperm: process:COPULATION

-gametes are produced inGONADS by the process calledGAMETOGENESIS which occurs when theorganism is sexually matured

-sperm cell / spermatozoaproduction SPERMATOGENESIS

-egg cell/ ova productionOOGENESIS

-FERTILIZATION: activation ofthe egg (entry of sperm) + AMPHIMIXIS(fusion of egg and sperm nuclei)

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BIO 3 Handout