Endocrine Glands Part 1 Flashcards
how does the endocrine system communicate
via chemical messengers (hormones), secretory products of endocrine cells, carried by bloodstream to target tissue containing receptors
what are endocrine organs composed of and characterized by
secretory cells of epithelial origin and characterized by prominent nuclei and numerous organells
how do endocrine organs secrete hormones
lack ducts and secrete hormones into surrounding interstitial space
describe the blood supply in endocrine organs
rich blood supply with fenestrated capillary networks to absorb and transport hormones
what do endocrine organs integrate
function of physiologic systems
what does the hypothalamus do
-coordinates endocrine functions of the body
- acts as intermediary between autonomic nervous system and endocrine system
what tissue types are present in pancreas
endocrine and exocrine tissue intermixed
what is another term for the pituitary gland
hypophysis
describe the pituitary gland
~1cm diameter, specialized appendage of brain
where is the pituitary gland located
beneath third ventricle in sella turcica (“Turkish Saddle”) of sphenoid bone
what controls the secretion of pituitary hormones
hypothalamus
describe the blood supply of the pituitary gland
includes hypophyseal portal system which allows communication with hypothalamus
what is the function of the hypothalamus
controls secretion of anterior pituitary via hypothalamic regulating factors (hormones)
what do releasing factors do
stimulate secretion
what do inhibitory factors do
inhibit secretion
what are the 2 groups of pituitary hormones
direct acting hormones and trophic hormones
what is the target organ of direct acting hormones and examples
non-endocrine target organ
ex: GH, ADH, MSH, oxytocin, prolactin
what is the target organ of trophic hormones and examples
another endocrine gland
ex: TSH, ACTH, FSH, LH
what are the pituitary dependent endocrine glands
thyroid gland, adrenal cortex, and gonads
what is the pituitary divided into
functional, anatomical, and embryological anterior and posterior portions
what does the anterior pituitary gland contain
glandular epithelial tissue
what does the posterior pituitary gland contain
neural secretory tissue
what are other names for the anterior pituitary
-“master gland”
- adenohypophysis
-pars anterior
- pars distalis
what is the anterior pituitary derived from
evagination of ectoderm from oral cavity in region of pharynx called Rathke’s Pouch
what are the 3 distinct regions of the anterior pituitary tha Rathkes pouch differentiates into
-pars distalis, pars intermedia, pars tuberalis
describe pars distalis
bulk of anterior pituitary
describe pars intermedia
thin layer between anterior and posterior pituitary, contains remnants of Rathke’s pouch
what does pars intermedia secrete
MSH and ACTH
describe pars tuberalis
extension of anterior pituitary, forms infundibulum