1. Chapter 40 ~An Introduction to Animal Structure and Function I. Tissues: groups of cells with a common structure and function (4 types)

2. A. Connective tissue: –1. structure - a. most abundant & widely distributed b. Exists in more varied forms than any other tissue c. Form of connective tissue determined by matrix –matrix is non-living material between cells –2. function – a. forms a supporting framework for body as a whole & individual organs :

4. 3. 3 types –Collagen fibers (protein)– flexible –Elastin fibers (protein) rubbery –Reticular fibers (thin branched collagen fibers) 4. examples: –Blood – fluid matrix –Adipose – gel-like & sparse –Bone – most specialized –Cartilage & fibrous

5. B- Epithelial tissue: –1. structure a. held together by tight junctions (very little matrix) b. forms continous sheets that are avascular –Avascular = no blood vessels (gets materials through osmosis –2. function a. protective lining outside of body and protective lining of organs and cavities (includes mucus membrane) b. identified by shape

6. 3. examples a.Simple: single layer of cells b.Stratified: multiple tiers of cells c.Cuboidal (like dice) d.Columnar (like bricks on end) e.Squamous (like floor tiles)

8. C.-Nervous tissue: senses stimuli and transmits signals from 1 part of the animal to another –1. Structure A. 3 types of nerve cells- sensory, motor, assoc. –2. function A. to receive, interpret, & respond to stimuli

9. D- Muscle tissue: capable of contracting when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types: –1. structure A. Large, long cells B. 3 types –1) striated/skeletal –2) smooth – organs, involuntary –3) cardiac – heart

11. II. Organization A. levels or organization: Atom Molecule Cell Tissue Organ System Organism (population, community) Circulatory-internal distribution Digestive-food processing Excretory-waste disposal; osmoregulation Endocrine-coordination of body activities Immune/Lymphatic-defense Integumentary-protection Muscular-movement; locomotion Nervous-receive, interpret, responedto stimuli Respiratory-gas exchange Reproductive-reproduction Skeletal-support; protection

12. III. Internal regulation A. Interstitial fluid: internal fluid environment of vertebrates; exchanges nutrients and wastes B. Homeostasis: “steady state” or internal balance

13. C. Negative feedback: –1. change in a physiological variable that is being monitored triggers a response that counteracts (negatively) the initial fluctuation; 2. ex. body temperature D. Positive feedback: –1. physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change (positively) –2. ex.uterine contractions at childbirth

14. IV. Metabolism: sum of all energy- requiring biochemical reactions A. terms –1. Basal Metabolic Rate (BMR): minimal rate powering basic functions of life (endotherms) –2. Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)

15. B. Thermoregulation- maintaining body temp –1. Endotherms aka homeotherms: bodies warmed by metabolic heat Body temp constant –2. Ectotherms: aka poikliotherms bodies warmed by environment Body temp changes with environment –3. regulation of body temp

16. 3. regulation of body temp –a. cooling by evaporation Sweating –b. warming by metabolism Muscle contraction & other metabolic activities generate heat –c. adjusting surface area to regulate temp Change vol of blood flow to extremities

17. d. countercurrent exchange – (in cold environs) warm blood moving to extremities runs adjacent to cold blood moving away from extremities – heat absorbed by cold blood is redistributed to internal parts of body