Topic 1: Intro Flashcards
What is physiology?
Study of how the body functions
This is the ability to maintain relatively stable conditions in the internal environment
Homeostasis
What are some examples of conditions that are controlled to maintain homeostasis?
pH
Temperature
Blood gasses
Blood pressure
ICF & ECF volumes
Disease comes from a failure to …
maintain homeostasis.
What are the systems that control all other systems?
Nervous system
Endocrine system
What do the control systems respond to?
Changes in the internal environment
What are the types of nervous/endocrine responses?
Anticipatory responses
Feedback mechanisms (respond to change)
What response does this exemplify?
Proprioceptors signalling movement BEFORE an internal change of conditions, causing increased respiratory rate at the start of exercise
Anticipatory response
What are the 3 basic components of feedback mechanisms?
Receptors
Control centres
Effectors
What is a set point?
Range of a variable (eg. body temp) which is in the normal range
Is negative feedback more or less common than positive?
Negative is far more common
What makes it “negative” feedback?
It moves the variable BACK (negative) to the set point
What is the basic process to trigger a nervous/endocrine response?
Stimulus (high body temp)
detected by
Receptor (thermostat cells)
input
Control centre (brain)
output
Effectors (blood vessels/sweat glands)
Why is positive feedback less common?
It is NOT homeostatic; it intensifies the input and moves it further away from the setpoint
What is an example of positive feedback for the regulation of homeostasis?
Pregnancy
