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PHYSIOLOGY NOTES/COMMENTS/QUESTIONS

~ Physiology is largely the study of processes related to homeostasis ~

UNIT 1: HOMEOSTATSIS

CHAPTER 1: MECHANISMS OF MAINTAINING HOMEOSTASIS homeostasis involves three mechanisms for maintenance: 1. the receptor 2. the control center 3. the effector

when a change in homeostasis occurs, the system will use either produce a - 1. negative feedback: a response that REVERSES the direction of the change (example: when an increase in body temperature is detected, the brain triggers negative feedback to DECREASE temperature in order to return to homeostasis levels) receptor: the skin detects a change control center: the brain sends a command effector: the skin decreases temperature

2. positive feedback: a response that AMPLIFIES the change (example: after getting a cut, your blood will start to clot at the spot to cover the cut. this is an example of positive feedback)

NB: positive feedback is rarer than negative feedback, as the end result is not homeostasis. positive feedback shifts the system to a new situation of homeostasis.

MALFUNCTIONS IN HOMEOSTASIS homeostasis can malfunction, meaning that the body is no longer able to maintain homeostasis in because of one of two occurrences - 1. deficiency: the cells are not getting enough resources 2. toxicity: cells are being poisoned by things they don't need an example of homeostasis malfunction is when the blood does not clot

a malfunction in homeostasis can be fixed or worsened by an internal mechanism OR several external influences: 1. nutrition 2. toxins 3. psychological 4. physical 5. genetic/reproductive 7. medical

CHAPTER 2: HOMEOSTASIS THROUGHOUT THE BODY A. THE NERVOUS SYSTEM

____________________________________________________________ Books to read on precognition: Aristotle, On Divination in Sleep JW Dunne, An Experiment With Time