HSF 3 - Unit 2 Histology: Endocrine Glands Flashcards
how does the endocrine system communicate with other parts of the body?
via chemical messengers (hormones) that are secretory products of endocrine cells, which are carried via the bloodstream to the target tissue that contains receptors
what are endocrine organs composed of? type of cell, cell characteristics, and their origin?
secretory cells from epithelial origin, prominent nuclei and numerous organelles; lack ducts so secrete hormones into surrounding interstitial space
what is special about the blood supply of endocrine organs?
rich supply with fenestrated capillary network: good for absorbing and secreting hormones
what important function does the hypothalamus have?
coordinates endocrine functions of the body by being an intermediary between the ANS and endocrine system
what do most endocrine glands form and where are these found?
discreet organs, found in pancreas where the endocrine and exocrine tissue is intermixed
what is another name for the pituitary gland?
hypohpysis
where is the pituitary gland found and how big is it?
1 cm, lies beneath the 3rd ventricle of the brain within the sella turcica of the sphenoid bone
what controls secretions of the pituitary?
the hypothalamus
what is the blood supply of the pituitary? what does this allow?
complex: contains hypophyseal portal system, allows communication between hypothalamus and pituitary
what are the different kinds of hormones secreted by the pituitary gland?
trophic and direct acting
what are trophic hormones? which ones are they?
the target organ of the hormone is another endocrine gland, TSH, ACTH, FSH, LH
what are direct-acting hormones? which ones are they?
the target organ is non-endocrine; GH, ADH, MSH, oxytocin, prolactin
what are the glands that are pituitary-dependent?
thyroid, adrenal cortex, and gonads
how is the pituitary divided?
into posterior and anterior portions functionally, anatomically, and embryologically
what kind of tissue is found in each division of the pituitary?
anterior: glandular epithelial tissue
posterior: neural secretory tissue
what is the anterior pituitary known as?
master gland = adenohypophysis = pars distalis = pars anterior
what is the embryological origin of the tissue of the anterior pituitary?
arises from evagination of the ectoderm from the oral cavity in the pharynx in the Rathke’s pouch region
what are the divisions of the developed Rathke’s pouch?
pars distalis (bulk; secretes most hormones, some of each kind) pars intermedia (between anterior and posterior pituitary) pars tuberalis (stalk/infundibulum)
what does the pars intermedia do? what special feature can be found here?
secretes MSH and ACTH; cystic remnants of Rathke’s pouch
what hormones are secreted by the pars distalis?
GH and prolactin (direct-acting)
TSH, ACTH, FSH, LH (trophic)
how does the hypothalamus influence pituitary secretions?
controls via hypothalamic regulating factors (hormones); releasing and inhibitory factors
what are the different types of cells within the anterior pituitary?
2 kinds of secretory cells: chromophils (stain) and chromophobes (don’t stain)
how do chromophils stain?
acidophils (acidic dye and turn pink in H&E) and basophils (basic dye and turn pale blue-purple in H&E)
how do chromophobes stain? what do they represent?
don’t take up dye, clear on H&E and represent inactive cells