13.3 Regulation

adrenal glands

two glands on top of kidneys composed of inner adrenal medulla and outer adrenal cortex

adrenal medulla

produces epinephrine and norepinephrine which regulates short-term stress response (fight or flight)

epinephrine

increases heart/breathing rate, raises blood glucose for quick energy, widens airways

norepinephrine

constricts blood vessels which increase blood pressure, helps maintain alertness/focus

short-term stress response

fight or flight, adrenaline-based

long term stress response

sustained stress management (cortisol based)

adrenal cortex

produces glucocorticoids such as cortisol which increase blood glucose levs and the breakdown of proteins during long term stress response

cortisol

steroid hormone secreted in adrenal cortex after stimulated by ACTH. increases glucose profuction by promoting the break down of proteins and fats

adrenocorticotripic hormone (ACTH)

released from anterior pituitary gland and stimulates adrenal cortex to produce glucocorticoids

aldosterone

increases sodium reabsorption in kidneys which causes water retention; higher blood volume and pressure; more potassium excretion

how does cortisol increase blood glucose?

promotes breakdown of proteins into amino acids which is taken by the liver to make glucose. the breakdown of fats also makes glucose

negative feedback on cortisol regulation

increased cortisol levels cause negative feedback into hypothalamus/pituitary glands and inhibits the production of ACTH