Endocrine Histology Flashcards
specialized cells which secrete substances that affect other cells
endocrine cells
common features of all endocrine tissues
ductless, vascular, epithelial, polyhedral, blocks/plate/cord organization
T/F endocrine tissues are ductless
T
Endocrine cells secrete substances into _____
interstitial fluid –> bloodstream (high vascularity)
fenestrated epithelium
allows passage of molecules into capillaries by endocrine glands
Which endocrine glands have an epithelial growth pattern?
thyroid, parathyroid, anterior pituitary, adrenal cortex, pancreatic islets –> cords or clumps of cells attached to each other
Which endocrine gland is mesodermal in origin?
adrenal cortex
Which endocrine glands have mesenchymal growth pattern?
leydig and ovarian stromal cells,granulosa, and luteal –> connective tissue organization
Which endocrine glands have neural growth pattern?
posterior pituitary, adrenal medulla
T/F endocrine cells can be individual
T –> enteroendocrine cells, enuroendocrine cells, and juxtaglomerular cells are distributed throughout
The ______ connects the pituitary to the hypothalamus
infundibulum
derivation of anterior pituitary
ectoderm of oropharynx (rathke’s pouch)
derivation of posterior pituitary
neuroectoderm of floor of third ventricle
anterior pituitary secretes:
gh, prolactin, lh, fsh, tsh, acth
posterior pituitary secretes:
oxytocin and ADH
3 parts of anterior pituitary
pars distalis, intermedia, tuberalis
pars distalis
bulk of AP, arises from anterior wall of RP
pars intermedia
remant of posterior wall of RP
pars tuberalis
forms sheath around infundibulum and contains veins from hypothalamus/thalamus
The primary portion of the PP is called _____
pars nevrosa
3 main cell types in AP
chromophils (acidophils: pink and basophils: purple on h/e) and chromophobes
Which endocrine cells are acidophils?
somaotropes and lactotropes (gh and prl)
Which endocrine cells are basophils?
corticotrpes, gonadotropes, thyrotropes (ACTH, LH/FSH, TSH)
nerve axons in the hypothalamohypophyseal tract are myelinated/nonmyelinated
nonmyelinated –> non synaptic and secrete hormones vs nt’s
glial cells in the posterior pituitary are called
pituicytes
thyroid is derived from ____
endoderm of pharyngeal floor
lobes of thyroid
pyramidal, right, left and isthmus
Extracellular thyroglobulin called ____ accumulates in the _____
colloid –> follicles
Characteristic feature of thyroid
follicles with large lumen surrounded by simple cuboidal epithelium
thyroglobulin is used to produce ___ and ___
T3 and T4
_____ cells produce calcitonin
parafollicular C cells
How many parathyroid glands are there?
4 –> lower glandsderived from 3rd branchial arch like thymus/upper glands from 4th branchial arch
Role of parathyroid
regulate calcium metabolism
T/F fat cells in parathyroid increase with age with 60-70% of glands becoming fat
T
3 types of parenchymal cells in parathyroid
principal/chief cells (present before birth), oxyphil cells (acidophlic, after puberty), adipocytes (more with age)
_____ cells make pth
chief cells
Which part of adrenal is larger? cortex, medulla
cortex = 90% of weight
The _____ contains cells similar to sympathetic neurons which secrete catecholamines in the adrenal
medulla
3 zones of adrenal cortex
glomerulusa (mineralocorticoids/aldosterone), fasciculata (glucocorticoids/cortisol), reticularis (gonadocorticoids/adrogens)
T/F adrenal medulla cells are considered post-synaptic neurons
T –> but no axons (probably due to cortisol inhibition)
2 types of chromaffin cells
large dense core: norepi, small core: epi –> adrenal medulla
the adrenal medulla is composed of ____ cells
chromaffin
exocrine pancreas is composed of ____
acini and ducts and produce enzymes for digestion
endocrine pancreas is composed of ____
islet cells: islands of neuroendocrine cells
islets develop during ___ weeks gestation
9-12 weeks
islets are most numerous in which portion of pancreas
tail
cell types in pancreatic islets
A (glucagon), B (insulin), D (somatostatin), PP(pancreatic polypeptide), D1 (VIP), EC (secretin, substance p, motilin)
