Lec 30 Endocrine System Flashcards
describe the negative feedback mechanism
hormone level decreases -> secretion of hormone inc -> hormone level inc -> glands stop secreting hormone (since there is now enough)
where is the pituitary gland located?
interior surface of brain
attached to hypothalamus
surrounded by wall of willis
what is the structure of the pituitary gland?
2 distinct lobes -> adenohypophysis, neurohypophysis
what is the difference between adenohypophysis and neurohypophysis?
adenohypophysis - no storage, production instead. anterior glanduar portion (produces) produces and secretes 6 major hormones
neurohypophysis posterior storage nervous portion stores and releases 2 hormones by hypothalamus
what are the hormones secreted by the pituitary?
growth hormone, thyroid stimulating hormone, adreonocroticotropic hormone, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, oxytoxin, antidiuretic hormone
what is the action of growth hormones?
increases protein synthesis & mitosis
regulates growth of most cells of the body
what is the action of ACTH?
controls secretions of hormones of the adrenal cortex
what is the action of luteinizing hormone?
plays role in ovulation
stimulates secretion of sex hormones
what is the action of prolactin?
secretion of milk from mammary glands
what is the action of oxytocin?
stimulates uterine contractions
promotes milk ejection from breast
what is the action of antidiuretic hormone?
affects permeability of the kidney tubules to reduce the excretion of water
which 2 hormones secreted by the pituitary is made in the hypothalamus
oxytocin and ADH
where is the thyroid gland located?
anterior neck inferior to larynx
surrounds anterior and lateral aspect of trachea
what hormones are secreted by the thyroid gland
throxine (T4), triiodothromine(T3), calcitonin
what is the structure of throxine and triiodothyromine?
2 lobes connected by an isthmus, may contain pyramidal lobe
what is the effect of the thyroxine and triiodothyromine glands?
regulates metabolic rate
what is the structure of calcitonin?
cuboidal cells - hormone production
follicles - store hormones
what effect does calcitonin have?
regulates osteoclast activity and lowers blood calcium levels
where is the parathyroid gland located?
embedded on posterior side of thyroid gland
where is the site of action for the parathyroid gland?
osteoclast in bone, kidney, intestine
what is the effect of the parathyroid gland?
increase in blood calcium levels
where are the adrenal glands located?
superior pole of the kidneys
what hormones are secreted by the adrenal glands?
androgens (estrogen / progesterone)
epinephrine
aldosterone (mineracorticoid)
cortisol hydrocortison (a glucocorticod)
where is the site of action of aldosterone?
kidney tubules
what is the effect of aldosterone?
regulates Na & K levels
what is the effect of cortisol hydrocortison?
prevent/ reduces inflammation
what hormone do beta and alpha cells secrete?
beta - insulin
alpha - glucagon
which part of the pancreas contains the beta and alpha cells?
endocrine
where is the site of action for exocrine cells?
ducts
what is the effect of beta cells vs alpha cells?
beta cells regulate transport of glucose into cells
alpha cells convert glycogen into glucose
what hormone does the pineal gland secrete?
melatonin
what does ACTH stand for?
adrenocorticotropic hormone
what does TSH stand for?
thyroid stimulating hormone
what is the difference between prolactin and oxytocin?
prolactin produces milk, oxytocin ejects milk
which 2 hormones in the pituitary stimulate sex hormone secretion?
follicle stimulating
lutenizing hormone
what is the effect of the thyroid gland?
regulates basal metabolic rate
where is the site of action for thyroid gland?
most cells
where is site of action for calcitonin?
bones
which hormones of the adrenal gland are made in the cortex?
androgens, aldosterone, cortisol hydrocortison
which hormone of the adrenal glands are made in the medulla?
epinephrine
what is the inner portion and outer portion of the adrenal glands?
inner - medulla
outer - cortex
