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Download An Introduction to Animal Structure and Function
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Basic Principles of Animal Form and Function Levels of Structural Organization Body plan and External Environment Regulating the Internal Environment Levels of Structural Organization • Hierarchy of multicellular organisms • Celltissueorganorgan system Organ Systems • • • • • • Integumentary Skeletal Muscular Digestive Nervous Circulatory • • • • • Respiratory Immune/Lymphatic Excretory Endocrine Reproductive Tissue Groups of cells with common structure and Function, four types: • Epithelial • Connective • Nervous • Muscle Epithelial Tissue • Tightly packed • Lines organs and body cavities, covers the body • Classified by shape and by number of layers Connective Tissue • Characterized by a sparse cell population scattered through an extensive extracellular matrix • Major types: loose connective, adipose, fibrous connective, cartilage, bone, blood Nervous Tissue • Senses stimuli and transmits signals from one part of the animal to another • Neurons – nerve cells Muscle Tissue • Consists of long excitable cells capable of contraction • Most abundant tissue in animals • Three types: skeletal, smooth, and cardiac Regulating the Internal Environment • Interstitial fluid-composed of fluid between the cells of vertebrates • Homeostasis-dynamic state of equilibrium in which internal conditions remain relatively stable; “steady state” Thermoregulation • Adjust rate of exchange between animal and it’s environment • vasodilation • vasoconstriction • countercurrent heat exchange • evaporative heat loss • behavioral responses • rate of metabolic heat production Regulation of Body Temperature • Heat gain or loss in organisms results from: conduction, convection, radiation, and evaporation • Ectotherms: absorb heat from the environment, most invertebrates, fishes, reptiles, and amphibians • Endotherms: derives most of their heat from metabolism, mammals, birds, some fish, and numerous insects Ectothermy • Body orientation to the sun (locust) • social organization (honeybees) Endothermy • Ability to regulate metabolism • Humans and other terrestrial mammals utilize hypothalamus • Feedback through nervous system results in vasodilation or vasoconstriction to skin vessels Counter Current Heat Exchange Heat Shock Proteins • Found in animal cells, yeast, and bacteria • cells are able to make RAPID adjustments to temperature changes • prevent denaturation • produced by heat-shock genes Torpor during Environmental Extremes • Hibernation • Estivation • Daily torpor (diurnal vs nocturnal)
