Physiological Homeostasis (week 1) Flashcards
Define homeostasis
An evolutionary development of metabolic wisdom that provides for internal constancy. Homeostasis is not steady state but a dynamic equilibrium
Give examples of responses to physiological stimuli
In honeostastis
Increased heart rate during exercise
Fever when unwell
Increased urination after drinking
Give examples of situational homeostasis
Eating when hungry
Wearing a hat in the sunshine
Holding your breath while swimming
List some factors under homeostasis control
Nutrients
Gases
Waste products
pH
Salt and other electrolytes
Temperature
Volume and pressure
Describe negative feedback loop
When the product of a reaction leads to a decrease in that reaction
Give an example of a negative feed back loop
Sensor (skin hypothalamus) —> comparator (hypothalamus) —> effector (sweat glands leads to sweating) —-> variable (heat loss)
Define positive feedback loop
When the product of a reaction leads to an increase in that reaction
Give an example of positive feedback loop,
Come back later
Describe principles of and the components of the physiological feedback loop
Stimulus
Receptor
Control centre
Effector
response
What is feedforward, and give an example
Is an anticipatory change in physiological variable.
Salivation in anticipation of eating
What does persistent deviations from homeostasis mean
Diseaseeeee