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Physiology Overview - Vertebrates

Physiology Overview - Vertebrates. Chapter 40. What you need to know. The four types of tissues and their general functions The importance of homeostasis and examples How feedback systems control homeostasis and 1 example of positive feedback and 1 example of negative feedback.

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Physiology Overview - Vertebrates

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  1. Physiology Overview - Vertebrates Chapter 40

  2. What you need to know • The four types of tissues and their general functions • The importance of homeostasis and examples • How feedback systems control homeostasis and 1 example of positive feedback and 1 example of negative feedback

  3. Organ Systems (On AP Test) • Digestive System (nutrition/solid waste) • Endocrine System (regulation) • Respiratory System (gas exchange) • Circulatory System (transport) • Excretory System (homeostasis, liquid waste)

  4. Organ Systems • Integumentary System (Cartilage, connective tissues) • Nervous System (integration of body and environment through senses) • Muscular System (locomotion) • Lymphatic Immune System (defense) • Reproductive System • Skeletal System (bones)

  5. Hierarchy • Cells  tissues  organs  organ systems • Example: • Neurons  nervous tissue  brain  nervous system

  6. Specialized Cells/Tissue • Epithelial cells (endoderm & ectoderm): • Cells that cover interior and exterior body surfaces including glands • Skin, lining of lungs, and all other organs • Tight junctions • Connective Tissue (mesoderm): • Supports the body, and connects parts together • Connective, adipose, cartilage, bone, and blood • Loose connections

  7. Specialized Cells/Tissue • Nervous tissue (ectoderm): • Conducts impulses throughout the body • Nerve cells, brain cells, and spinal cord • Muscle tissue (mesoderm): • Actin/myosin cytoskeleton parts in cytoplasm of muscle cells convert ATP into movement • Skeletal muscles, smooth muscles, and cardiac muscles

  8. Metabolism • ATP production through cellular respiration • Metabolic rates in organisms determined by ATP requirements for survival • High in endothermic • Low in exothermic (approx. 90% lower)

  9. Homeostasis • Dynamic set of mechanisms that regulate internal environment

  10. Homeostasis – steady state • All organisms do homeostasis • Isolation from environment is impossible for survival • External environment changes the internal environment • Wide fluctuations in external environment • Stable internal environment promotes healthy metabolism

  11. Feedback Loops • Regulate body functions • Receptor • detects change • Control center • receives info from the receptor and directs response • Usually hypothalamus • Effector • Carries out response

  12. Negative Feedback Loops • Effectors reduce change, preventing small changes from becoming big changes • Most homeostatic mechanisms are negative feedback loops: temp, blood sugar, pH, hydration, and oxygen supply

  13. Negative Feedback Example

  14. Positive Feedback Loops • Change stimulates response that further amplifies change (rare) • Childbirth: • Stimulus: pressure of head on cervix • Response: increased contractions

  15. Thermoregulation/Endotherms • Source of body heat = intense metabolism • Metabolism increases 2x every 100 Celsius • Body temp is independent of environment • Mostly high temperatures that are narrowly regulated • High food consumption • Body surface area/volume ratio is important • Mammals and Birds

  16. Variations of Thermoregulation • Poikilotherms: large variation of body temperature • Marine fish tend to have body temperatures higher than water due to high metabolisms • Hibernation in some mammals • Homeotherm: stable body temperature • Humans

  17. Heat Production/Conservation • Insulation: fur, feathers, blubber • Acclimations: seasonal change of winter/summer coat, and membrane fluidity (regulated by fatty acids) • Shivering: muscle contractions regulated by hormones (adrenalin, thyroxin) • Insects shiver and/or rub their wings

  18. Heat Regulation Mechanisms • Counter current exchange • temperature exchange between incoming and outgoing blood flow • Bird feet, fish fins, marine mammal flippers • Vasoconstriction: smooth muscle nodes around capillaries reduce blood flow to extremities (conservation) • Vasodilation: relaxation of smooth muscles increases blood flow (radiation)

  19. Heat Regulation Mechanisms • Hibernation: lowering of body temp and activity level to save food stores • Behaviors: avoiding/seeking heat, shade, cool water • Sweating: heat loss through evaporation from skin • Panting: heat loss through evaporation of saliva

  20. Heat Regulation Mechanisms • Large extremities: ears/tail for heat loss • Small extremities: for heat retention • Hypothalamus: Thermo-regulator in the brain

  21. Hypothalamus • Nerve cells in the hypothalamus can detect if blood temperature is off • Below set point: induction of shivering and vasoconstriction of tissues in extremities (raise/conserve core temperature) • Above set point: induction (adrenalin and glucagon) of sweating, panting, and vasodilation (lower core temperature)

  22. Endocrine System • Produces hormones that regulate homeostasis, reproduction, and development • Characteristics of hormones include: • Transported by blood • Minute amounts required to stimulate body wide response • Are either steroids, peptides, or amino acids

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