Physiological adaptations for survival

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Physiological adaptations for survival
2014-01-29 10:19:01
Biology chapter 10 physiological adaptations unit vce

Chapter 10 of biology
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  1. What is homeostasis?
    • The condition of a relatively stable internal environment maintained within narrow limits
    • eg. core temperature, water levels, glucose, pH of blood
  2. What are affector neurons?
    • Detect change in internal or external environment
    • Sends electrical impulses to CNS
  3. What are effector neurons?
    Neurons that carry impulses away from the CNS to produce a response (muscles and glands)
  4. What is the endocrine system and what is it responsible for?
    • A system of internal control in animals that involve the release of hormones into the blood.
    • Hormones reach the site of action through diffusion
    • Much slower than nervous system however long lasting.
    • Responsible for maintaining homeostasis
  5. What is negative feedback?
    The response reduces the effect of the original stimulus. That is, the response has a negative effect on the stimulus, cancelling or counteracting it.
  6. What are ways of losing heat?
    • Radiation: Heat in the form of infrared rays
    • Conduction: movement of heat away from the body in water
    • Convection: movement of heat away from the body in air
    • Evaporation of sweat
    • Vasodilation
    • Less adrenaline and thyroxine produced for slower metabolism
  7. What are ways of gaining heat?
    • Shivering: contraction and relaxation of small muscle groups
    • More thyroxine and adrenaline =Metabolic processes
    • Vasoconstriction: less heat lost through blood
    • Piloerection: goosebumps, thin layer of insulation
  8. What is the difference between ectothermic and endothermic animals?
    • Ectothermic: rely on external temperatures to gain body heat
    • Endothermic: rely on internal mechanisms to generate body heat
  9. What is the difference between poikliothermic and homethermic animals?
    • Poikliothermic: fluctuating internal temperatures
    • Homeothermic: constant internal temperatures
  10. Describe the processes involved in maintaining water balance in mammals
    • ·Regulated by kidneys. Also called osmo-regulation
    • ·Two Significant hormones are involved– Vasopressin and Renin
    • ·Osmo-receptors detect changes in water balance in the body – When there is a drop in water concentration, Vasopressin is released into the bloodstream.
    • ·Vasopressin increases re-absorption of water in the kidneys