homeostasis

homeostasis

maintaining relative constancy in response to internal and external changes

goal of homeostasis?

to survive

pathophysiology

an imbalance inside the body , like diseases

medicine relative to homeostasis

a form of behavioral mechanism it helps identify whats imbalanced in the body and bring it back to balance

common homeostasis examples

O2 and CO2 levels, levels of nutrients in blood (ex.glucose)

how is proper blood nutrient levels controlled?

insulin (stimulates brings down glucose) glucagon (stimulates to release glucose when levels are low)

how is waste removed from blood?

urea , important to remove excess molecules, regulate molecules, and reabsorb water (in kidneys)

adrenaline function?

respond to stimuli, regulates proper heart rate and blood pressure

respiratory (maintaining proper oxygen levels in blood)

brain and respiratory adjust breathing rate, too much O2 is bad but too little also dangerous

CO2 role

helps keep pH balanced, stimulates automatic breathing rate and when not enough can be dangerous because stimulates respiration

body posture and simple muscle reflexes

Proper posture keeps the spine's natural curves aligned and distributes the body weight evenly

control mechanism steps

stimuli, receptor, afferent pathway, control center, efferent pathway, effector, response (optional)

stimulus

is a change that may EVOKE a response

is stimulus required for a homeostatic response?

YES

receptor

stimulus detector, how you know stimulus happened

afferent pathway

input pathway, takes info from receptor to control center

control center

analyzes info as it compares to body’s set point; decision maker

efferent pathway

takes info/ decision from the control center to the effector

effector

mechanism that can do the response

response

a response does not always occur

negative feedback loop

control mechanism decreases intensity of condition to bring back to set point

positive feedback loop

control mechanism increases intensity of condition

stimulus in child birth

increased pressure and tension in cervix

receptor in childbirth

mechanoreceptors sensing increased muscle tension

efferent pathway in childbirth

posterior pituitary and oxytocin

effector in childbirth

myometrium in uterus

control center in childbirth

hypothalamus increases pressure and causes more muscle contraction

what makes childbirth a positive feedback loop

the increased pressure and muscle tension to release the baby

example of negative feedback loop?

eating a candy bar, blood sugar spikes, insulin is sent to bring the levels down (opposite)