Exam 3: Endocrine Part 2 Flashcards
where are the adrenal glands located? composed of?
located on the superior border of the kidneys
2 types of tissue
- glandular epithelium : cortex
- nerve tissue: medulla
cortex epithelium layers general characteristics
all steroid hormones, ACTH helps them get chlesterol and resist apoptosis
ACTH only directly effects the secretion of glucocorticoids from ____
zona fasciculata
3 layers of cortex epithelium
zona glomerulosa: mineral corticoids
zona fasciculata: glucocorticoids - fluid and electrolyte balance
zona reticularis: androgens - negligible amounts - if tumor you would not notice in men but would in women bc you would start to get masculinization
medulla
post ganglionic sympathetic nervous tissue - NE and epinephrine
aldosterone - zona glomerulosa
regulation
negative feedback loop in response to increased K+, decreased Na+, or decreased blood volume or P
release also stimulated by angiotensin II
aldosterone - zona glomerulosa
action
inc sodium and BP/V
inc permeability in kidney distal and collecting tubules by stimulating production of Na+ pumps
inc both Na+ and water
reabsorption
enhances ADH
stimulates taste bud sensitivity to salt- crave salty foods if dehydrated
short term activation of ACTH, chronic stress and ACTH release can convert glomerulosa to….
fasciculate with aldosterone secretion decreasing
cortisol - zona fasciculata
regulation
negative feedback loop with ACTH
circadian release, highest in morning, stimulated in response to stress
cortisol - zona fasciculata
action
inc blood sugar, promotes protein catabolism and AA release from cells
stimulates AA uptake and GLUCONEOGENESIS in liver
inhibits glucose uptake in muscles and adipose
stimulates lipolysis
suppresses inflammation and immune response
- infection risk if on lots of steroids
DHEA (androgen) - zona reticularis
regulation
small amounts released in response to ACTH
converted to testosterone in testes and adipose tissue
DHEA (androgen)-zona reticulata
action
not significant - action overshadowed by sex hormones
promotes bone and muscle growth in children
no effect in adult males
majority converted to estrogen in women
promotes blood cell production and muscle maintenance in women
a1, a2, b1,b2,b3
a1: vascular tissue
a2: digestive
b1: heart
b2: lungs
b3: adipose
epinephrine and norepinephrine
regulation
direct stimulation by sympathetic nervous system in response to stress
epinephrine and norepinephrine
action
inc HR and force of contractions
stimulates vasoconstriction, bronchodilation, pupil dilation
lipolysis and glycogenolysis
inc metabolic rate, inhibits GI secretion
80% released is epinephrine
kidney
filters the blood and is perfect site for monitoring blood composition
hormones in kidney inc blood oxygen levels and blood volume
erythropoietin
regulation
negative feedback loop
released in response to decreased oxygen levels in blood
erythropoietin
action
promotes production of erythrocytes in bone marrow
where is erythropoietin produced
interstitial cells that are associated with capillaries in kidney, peritubular capillaries are primary site of action
using EPO as a treatment
cancer patients if on chemo that is damaging bone marrow and they get anemia from treatment, can be given EPO
athletes run at high altitudes get release of this - some athletes inject EPO
renin
regulation
an ENZYME
negative feedback loop
released in response to dec Na+ levels or blood volume
inhibited by ANP and BNP
renin
action
converts serum protein angiotensinogen into angiotensin I
renin activates what 2 hormones
salt hormone (ADH) water hormone (aldosterone)
angiotensinogen
regulation and action
liver
regulation: negative feedback loop ; serum level regulated by liver
action: none
converted to angiotensin I by renin
somatomedin c (IGF-1) regulation and action
liver
regulation: release stimulated by Growth Hormone
action: negative feedback loop to regulate GH output
angiotensin II
regulation
LUNGS
regulation: initiated by renin release
angiotensin II
action
promotes vasoconstriction
stimulates release of aldosterone
indirectly enhances ADH
what lung enzymes activate angiotensin I
angiotensin converting enzymes (ACE)
ACE inhibitors can be used to treat
hypertension
2 functions of pancreas
endocrine and exocrine
endocrine cells of pancreas
grouped into aggregates known as islets of Langerhans
- regulation of islets is mainly linked to circulating glucose levels, however autonomic innervation can trigger hormone release
acinar cells
exocrine function
further discussed in digestive system unit
regulation of alpha cells: glucagon
negative feedback in response to low glucose levels (below 70)
sympathetic innervation stimulates release
triggered by low fatty acid levels - glucose sparing effect
raises blood sugar, not handled by pituitary
action of alpha cells: glucagon
stimulates glycogenolysis in liver and skeletal muscle
promotes gluconeogenesis in liver and lipolysis in adipose tissue - glucose sparing effect
regulation beta cells: insulin - pancreas
negative feedback in response to high glucose levels
sympathetic innervation inhibits release
triggered by high fatty acid levels, as well as gastrin, CCK, digestive hormone secretions
what is the only hormone that lowers serum glucose
insulin
insulin released in 2 phases
- initial burst of insulin - had meal, sugar level rises and insulin released starts to rise in 8-10min not going to peak until 30-45 min, should come down in an hour and a half to 2 hours - if does job this is it
- if eating constantly at a party and the 2 hr mark did not work
- gives you steady release of insulin
how is insulin released?
beta cells have transport vesicles of insulin waiting to be released
as glucose goes up they transport glucose in and it goes into glycolysis and get ATP which sets cascade to open Ca channels which causes exocytosis of insulin
action of beta cells: insulin - pancreas
inc glucose transporter activity - liver
promotes conversion of glucose to glycogen
stimulates glycolysis
inc protein synthesis
inc fatty acid uptake and triacylglycerol production in adipose
somatostatin
regulation and action
pancreas
regulation: not yet clarified
action: identical to GHIH produced in hypothalamus
- can inhibit both alpha and beta cells although exact function unclear
may slow food absorption
PP Cells - Pancreatic Polypeptide
regulation and action
regulation: released in response to ingestion, especially protein rich meals
action: satiation, dec appetite, plays role in moderating food intake
produced in stomach, stimulates GH and hunger
ghrelin
produced in stomach in response to food intake
stimulates acid production, mucous lining, and pancreas acini
gastrin
secreted by small intestine during fasting to maintain basic motility
motilin
secreted by duodenum in response to filling
stimulates pancreatic acinar and gallbladder secretions into duodenum
CCK (cholecystokinin)
produced by the duodenum in response to acid
stimulates release of water and bicarbonate from pancreas and gallbladder
secretin
released from small intestine in response to high fat and sugar content in food
slows motility and stimulates insulin release
gastric inhibitory polypeptide (GIP)
estrogen regulation
negative feedback in response to FSH and LH
cyclical
estrogen action
promotes follicle maturation, stimulates Ca Storage!!!, bone formation!!, angiogenesis
regulates development of secondary sex characteristics
where is estrogen produced
in ovarian follicles
angiogenesis
blood vessel formation
- lining of uterus, increases vascular portion of the lining
leptin in females vs males
females: leptin monitors nutrition state and fat %
males: monitors nutrition state
inhibin
regulation and action
regulation: stimulated by FSH
action: negative feedback with FSH, inhibits FSH and additional follicle development
progestin (progesterone)
regulation and action
regulation: negative feedback, release stimulated by LH
action: stimulates development of uterine endometrial lining, works with prolactin to stimulate mammary glands and lactation
what is progestin secreted by
corpus luteum
testosterone (androgen)
regulation and action
regulation: negative feedback - release stimulated by LH
action: promotes sperm maturation, stimulates Ca absorption, muscle and bone growth, regulates development of secondary sex characteristics
sertoli cells - inhibin
regulation and action
regulation: negative feedback, release in response to FSH
action: inhibits release of FSH
- aids in moderating sperm production
some stimulatory to TSH
stimulates maternal thyroid
maintains corpus luteum
hCG - human chorionic gonadotropin
similar to GH
promotes general growth
stimulates glucose metabolism
stimulates mammary duct proliferation
hCS - human chorionic somatomammotropin
promotes growth
IGF
acts on placenta
stimulates and maintains cells
EGF - endothelial growth factor
relaxes cervix and pelvic ligaments
relaxin
shifts maternal nutrient storage to meet needs of fetus
aids in transporting nutrients across placenta
leptin
