Semester exam: Homeostasis/feedbacks

Question 1

homeostasis

Answer 1

maintaining internal environment

A dynamic state of equilibrium

Question 2

effects of homeostatic imbalance

Answer 2

increase risk of disease
aging
can allow destructive positive feedback loops to take over

Question 3

What systems are involved in homeostasis

Answer 3

Nervous and endocrine systems

use nerve impulses and hormones

Question 4

Parts of homeostasis

Answer 4

receptor
control center
effector

Question 5

homeostasis pathway

Answer 5

stimulus produces change in variable
receptor detects change
input sent along afferent pathway to control center
output sent along efferent pathway to effector
effector responds to either enhance or reduce stimulus
back to homeostatic balance

Question 6

negative feedback loop

Answer 6

response reduces or shuts off original stimulus

Question 7

negative feedback examples

Answer 7

regulation of body temp

regulation of blood volume by ADH

Question 8

regulation of blood volume by ADH

Answer 8

receptors sense decreased blood volume
control center in hypothalamus stimulates pituitary gland to release ADH, which causes kidneys (effectors) to return more water to blood

Question 9

positive feedback loop

Answer 9

response enhances or exaggerates the original stimulus
can cause cascade or amplifying event
usually controls infrequent events

Question 10

positive feedback examples

Answer 10

labor contractions by oxytocin

platelet plug formation and blood clotting

Question 11

platelet plug formatino

Answer 11

tear in blood vessel
platelets connect to site and release chemicals
chemicals attract MORE platelets, platelet plug forms