Physiology of Endocrine System Pt 2 Flashcards
1
Q
adrenal glands
A
- located on top of left and right kidneys
- contains inner and outer portions connected via hormones
2
Q
medulla
A
- inner portion of adrenal glands
- secretes epinephrine + norepinephrine into bloodstream during stress conditions –> fight or flight response
3
Q
fight or flight response
A
- increased blood glucose level and metabolic rt
- blood vessels in intestine constrict, vessels in muscles dilate
- increased breathing + heart rt
- increased circulation to muscles
- increased stamina
- initiated by sympathetic nervous system but sustained by medulla
4
Q
adrenal cortex
A
- outer portion of adrenal glands
- essential to life (can’t be removed)
- make glucocorticoids, mineral corticoids
- product lower amounts of opposite sex hormones (e.g. testosterone in females)
5
Q
glucocorticoids
A
- main one = cortisol
- secretion controlled by ACTH from anterior pit. gland
- promotes hydrolysis of muscle protein to amino acids entering the blood, converts those into glucose, which increases glucose in the liver
- counteracts inflammatory response (decreases pain and swelling from inflammation)
- favors metabolism of fatty acids over carbs
- increases blood glucose level in opposition to insulin
6
Q
mineral corticoids
A
- main one = aldosterone
- regulates levels of sodium + potassium ions in blood by promoting renal absorption of sodium and excretion of potassium –> important for maintaining BP
7
Q
pineal gland
A
- located in 3rd ventricle of brain
- receives nerve impulses from eyes via optic tract
- produces melatonin (mainly at night)
8
Q
melatonin
A
- involved in circadian rhythms (daily cycles)
- high melatonin levels at night –> person feels sleepy
- low melatonin levels w/day light –> person wakes up
- disrupted by shift work, travel across timezones (jetlag)
9
Q
Pancreas
A
- two types of tissue: exocrine + endocrine
- exocrine tissue: produces + secretes digestive juices into small intestine
- endocrine tissue (pancreatic islets of Langerhans): produces insulin + glucagon, secretes them directly into bloodstream
10
Q
insulin
A
- hormone secreted by beta cells of pancreas when blood glucose levels high (after eating)
- decreases blood glucose levels via:
1. stimulating liver/fat/muscle cells to take up and metabolize glucose
2. stimulating liver/muscles to store glucose as glycogen
3. promoting fat/protein buildup + prohibiting their use as energy
11
Q
glucagon
A
- hormone secreted by alpha cells of pancreas between eating
- opposite actions of insulin: increases blood glucose levels via breakdown of stored nutrients
12
Q
female sex hormones
A
- estrogen + progesterone
-
13
Q
estrogen
A
- at puberty, causes growth of uterus and vagina
- necessary for egg maturation in ovaries
- responsible for secondary sex characteristics (femal body hair, fat distribution)
- breast development, regulation of uterine cycle
14
Q
gonads
A
- testes
- ovaries + uterus
- hormonal secretions controlled via FSH + LH from hypothalamus/pituitary gland
15
Q
testosterone
A
- produced by testes
- essential to normal development + functioning of male sex hormones, sperm maturation
- big increase of testosterone secretion @ puberty –> growth of testes + penis, beard/body + pubic hair, enlargement of larynx/vocal chords (why voice lowers)
- responsible for muscular strength, secretion of oil + sweat glands (–> acne + body odor), sex drive
