endo 1 W7 Flashcards
where is the pituitary gland located?
depression in sphenoid bone - hypophyseal or pituitary fossa
what is the pituitary fossa covered in? what passes through this?
shelf of dura - sellar diaphragm
infundibulum (pituitary stalk) passes through this
where are the cell bodies, axons and synapses of the magnocellular neurons located?
cell bodies - supraoptic and paraventricular nuclei of hypothalamus
axons - travel in pituitary stalk
synapses - posterior pituitary
what hormones travel down the axons of the magnocellular neurons?
oxytocin (cells from PVN) and vasopressin (cells from SON)
what hormones are made in the anterior pituitary? how is their release controlled?
ACTH
LH
FSH
TSH
GH
prolactin
release controlled by inhibitory and releasing hormones from the hypothalamus (travel via pituitary portal system)
relation of hypothalamus etc with other structures?
above optic chiasm
infundibulum emerges between optic chiasm and mammillary bodies
what structure is found immediately below the pituitary fossa?
sphenoid sinus
thyroid gland features?
left lobe
isthmus
right lobe
what nerve do the superior and recurrent laryngeal nerves both originate from?
vagus nerve (CN-X)
what nerve is vulnerable to damage during thyroid surgery?
what effect would this damage have?
the recurrent laryngeal nerve
hoarseness, potential difficulty breathing
what hormones are released by the thyroid gland? how is their release controlled?
T3, T4, Calcitonin
controlled by TSH release from anterior pituitary
where are the parathyroid glands found and what hormone do they release?
posterior aspect of the thyroid gland
release parathyroid hormone
blood supply to the thyroid?
superior thyroid artery (branches off external carotid)
inferior thyroid artery (branches off thyrocervical trunk, which is a branch of the subclavian)
which veins do the thyroid veins drain into?
superior and middle thyroid veins -> internal jugular vein
inferior thyroid veins -> brachiocephalic veins
what is the blood supply to the parathyroid glands? why is it important to be aware of this during surgery?
primarily branches from inferior thyroid arteries, collateral supply from superior thyroid arteries.
surgery risk of disrupting parathyroid blood supply when thyroid is being removed
where do the common carotid arteries bifurcate? Where do they lie relative to the thyroid?
bifurcates at upper border of thyroid cartilage.
lies posterior to thyroid gland.
parts of the pancreas?
head (curved, by duodenum)
neck (connects head and body)
uncinate process (end of curve)
body
tail (far left end)
what is the exocrine role of the pancreas?
produce digestive enzymes which are secreted into the duodenum
what hormones does the pancreas produce?
insulin, glucagon, somatostatin
where are the endocrine cells of the pancreas located?
pancreatic islets - embedded in the substance of the pancreas.
pancreas blood supply?
coeliac trunk -> splenic (great pancreatic) and common hepatic (gastroduodenal -> anterior/posterior superior pancreaticoduodenal)
superior mesenteric -> inferior pancreaticoduodenal arteries
pituitary general histology?
anterior pituitary - darker stained than rest
posterior pituitary - same colour as stalk
pars intermedia - cleft between lobes
pituitary cellular features on histology?
posterior - elongated nuclei of astroglial cells. orange stained blood vessels
anterior - glandular cells stain strongly. chromophobes don’t stain well. vascular sinusoids between.
what can chomophils be divided into
acidophils
basophils
thyroid histology features? - low power
external capsule
septa extend between conoid-filled follicles
follicular cells found around periphery
thyroid histology features? - high power
parafollicular cells (aka C cells) in septa (interstitial spaces) between thyroid follicles. large nuclei and pale cytoplasm. blood vessels between follicles.
parathyroid gland histology?
separated from thyroid by thin capsule.
chief cells (more numerous, lighter cytoplasm) and oxyphil cells
appearance of pancreatic islets? (histology)
paler staining groups of cells surrounded by pancreatic acini (exocrine part)
where are pancreatic alpha and beta cells found?
in pancreatic islet
what hormone do alpha cells secrete, and what does it do?
alpha cells secrete glucagon, which raises blood glucose levels
what hormone do beta cells secrete, and what does it do?
beta cells secrete insulin, which increase glucose uptake and thereby decrease blood glucose levels
