Chapter_41__ANIMAL_FORM_AND_FUNCTION[1]

Chapter_41__ANIMAL_FORM_AND_FUNCTION[1] - Chapter 41 ANIMAL...

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Unformatted text preview: Chapter 41 ANIMAL FORM AND FUNCTION Chapter Tissues and Homeostasis pp. 937­940 and 945­946 Summary *Organization of Living Things *Tissues *Epithelial *Connective *Muscle *Nervous *Homeostasis Form (Structure) and Function *Anatomy – physical structure *Physiology – function. *Evolution by natural selection based on changes in structure that allow organisms to function in their environment. * Chemicals – * Cells * Tissues * Organ * Organ system * Organism *4 basic types * Epithelial * Connective * Muscle * Nervous *Functions: Organization of Living Organisms Tissues Epithelial Tissue ***Regenerates quickly 1 *Structure: *2 types: simple and stratified (layered) *Epithelial tissue is polarized = 2 surfaces are different, fig 41.6. * Apical surface faces the environment * Basolateral surface is attached to other tissues. *Simple epithelium * Squamous: Epithelial Tissue * Cuboidal: * Columnar: *Stratified * Squamous: tough outer layer of keratinized cells; skin, etc. * Pseudostratified: ciliated cells that line the respiratory tract and glands. *Goblet cells Connective Tissue *Functions: *Supports *Packages and cushions organs *Transports materials. *Structure: *Matrix = ground substance with fibers (elastin, collagen, reticular) and cells. *3 types: proper, cartilage and special. *Connective Tissue Proper * Loose connective tissue – insulates, supports, nourishes and protects epithelial tissues. * Dense connective tissue – forms tendons, ligaments and capsules for organs. * Adipose (fat) – fuel storage, cushioning, insulation. * Cartilage – firm but flexible ground substance, chondrocytes (cells) in lacunae (spaces). Found in: 2 *Larynx *Bone surfaces at joints ■Nose and ear *Special ­ Bone *Functions: *Support *Levers for skeletal muscles *Blood cell production *Storage of Ca and PO4. *Structure *Organic matrix with collagen and rigid crystals of CaPO4. *Constantly remodeled by osteoclasts (tear down) and osteoblasts (rebuild). Mature cells are osteocytes that live in lacunae. *2 types: compact and spongy * Spongy – open lattice containing marrow for blood cell production or fat storage. * Compact – outer layer provides strength. Concentric rings (lamellae) laid down around a central canal = Haversian Canal. Nerves and blood vessles travel through this canal and nourish osteocytes. Connective Tissue *Special – Blood *Functions: transport of materials *Structure: *Plasma – fluid part of blood containing proteins, lipids, ions, nutrients, CO2, etc. *Cells *Cells * Erythrocytes * Leukocytes 3 * Platelets Muscle Tissue *Function: movement *Structure: specialized cells that have highly organized contractile filaments, actin and myosin. *3 types: * Smooth muscle * Skeletal muscle * Cardiac muscle Nervous Tissue *Function: generates and transmits electrical impulses *Structure: * Neurons = nerve cells * Neuroglia = supporting cells *Neuron Structure *Cell Body * Dendrites * Axon * Myelin sheath *Types of Neurons: * Sensory ­ peripheral nervous system. * Motor – central nervous system 4 * Interneurons ­ central nervous system. * Nerves are bundles of axons with blood vessels and ganglia are collections of nerve cell bodies. Homeostasis *Means –same or like standing. *In living things, it means the maintenance of internal chemical and physical conditions relatively constant despite changes in the environment. *2 ways to cope with the environment: * Conformational – adapting to environmental conditions, ex. ectothermic animals * Regulatory – active physiological processes that correct problems, ex. endothermic animals. *Regulatory processes – negative feedback loops, fig 41.14 and 41.16. *Internal conditions have a normal value or range of values = set point. Variations from the set point stimulate a … * Sensor that relays this information to an… * Integration center that evaluates the information and sends instructions, if necessary, to an… * Effector that corrects the problem and eliminates the signal to the sensor. *Regulatory systems ­ positive feedback loops *Used sparingly in living things. *Stimulus – integrations center ­ effector. In this case the effector does not eliminate the stimulus to the sensor and the physiological mechanism is amplified. Ex. Blood clotting, labor. 5 ...
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