endocrine system Flashcards
function of endocrine system
-what is the term for collection of cells which make chemical messengers
maintain homeostasis coordinading trillons of cells
cell communicate via chemical messengers (hormones) : nervous system and endocrine system
-glands
endocrine gland function
-where are they found
secrete hormones which travel in blood to target organ
-can be part of epithelila surface such as lining of digestive tract
seperate organs such as thyroid or pituitary glands
endocrine vs exocrine gland
exocrine- open contact with exteroir. ducts carry secretions to surface
endcrine- no open contact with exterioir
-no ducts, instead produce hormones secreted into blood
-some glands can be both exocrine and endocrine = pancreas
examples of endocrine system 1) pituitary and hypothalmus
-connection via infundibulum stalk
-function
monitors chemical and physical characteristics of blood.
secretes hormones which regulate pituitary function
Hypothalamo-hypophysial tract
-what does it connect
-how do they communicate
-function
-connects hypothalamus and posterioir pituitary
-communicates via neurons and extends through the infundibulum
hypothalamus makes neurohormones. stored in pituitary until needed and released from post pituitary when hypothalamus detects need
Hypothalamhypophysial portal
-what does it connect
-how does it communicate
-function
-connects anteroir pituitary to hypothalamus
-creates direct communication via portal blood vessels
-hypothalamus releases hormones which regulate anterioir pituitary hormone production. anterioir pitutairy secretes tropic hormone which stimulkates secretion of other hormones
example of production and release of growth hormone in anterior pituitary
1) hypothalamus release GHRH via portal blood system and travel to anterioir pituitary gland.
2) growth hormone released by anterioir
3) if to much growth hypothalamus secretes GHIH (inhibitory growth hormone)
what is thyroid gland regulated by?
hypothalamus released tTRH which acts on anterioir pituitary to stimulate thyroid stimulating hormone
thyroid gland histology
-what epithelial cells are the follicles
-what do the follicles produce
-where and how are they stored and released
-what is needed for thyrpid hormone synthesis
-why do parafollicular/ c cells produce calcitonin
-spheres of simple cuboidal
-T3 and T4
-stored and released from follicles in response to TSH from pituitary
-iodine from diet (seafood)
-calcium homeostasis
what two cells make up parathyroid glands
1) parathyroid (cheif) cells
2) oxyphil cells
1) small, dark stain produce prathroid hormone
2) large stain light, function unknown
adrenal histology
-function of inner medulla and outer cortex
-what is cushings syndrome
inner medulla= makes epinephrine (adrenaline)
outer cortex= make steroid hormones
cushing= increased cortisol production by adrenal. weight gain, sweating, hyperglycimia
pancreas
-where does it sit in body
-exocrine function (what produces pancreatic juice)
-endocrine function (what produces hormones)
-lies behind peritoneum
exocrine- acini produce pancreatic juice carried in duct to small intestine
endocrine- pancreatic islets secrete hormones into cirlulation
