Endocrinology USMLE Step 1
what is the embryonal origin of the adrenal cortex?(Ans- mesoderm
what is the embryonal origin of the adrenal medulla? what are the cells of the adrenal medulla called?(Ans- neural crest; chromaffin cells
T/F the chromaffin cells of the adrenal cortex are are considered preganglionic (Ans- false- postganglionic and ganglionic sympathetic
what autonomic is the adrenal medulla innervated by? what are the NT?what are the receptors called? what kind of receptors are they?(Ans- sympathetic; Ach; nicotinic (N); Na+/K ligand gated channels
what are the three layers of the adrenal cortex? (in order from outside to inside) which is the biggest?(Ans- Zona Glomerulosa, Zona Fasciculata, Zona Reticularis; Zona Fasciulata
what is the regulatory control of zona glomerulosa? and what does it produce in response?(Ans- renin-angiontensin (Ang II); Aldosterone
what is the regulatory control of the zona fasciculata? and what does it produce in response?(Ans- ACTH from ant pit (CRH from Hypothalamus); corticosteroids
what is the regulatory control of the zona reticularis? and what does it produce in response?(Ans- ACTH (ant pit) and CRH (Hypothalamus); sex androgens
- / 4
what is the regulatory control of the adrenal medulla? what is secreted in response?(Ans- preganglionic sympathetic fibers; catecholamines (epi, NE)
from what aa are catecholamines made?(Ans- tyrosine
what is the most common tumor of the adrenal medulla in adults?(Ans- pheochromocytoma
what is the most common tumor of the adrenal medulla in children? of what kind of cells is this tumor?(Ans- neuroblastoma; post ganglionic sympathetic neurons
what oncogene is upregulated in neuroblastoma? what does the gene transcribe?(Ans- N myc; a transcription factor
what type of hypertension does a pheochromocytoma result in?neuroblastoma?(Ans- episodic hypertension; diastolic hypertension
what can you find in the urine with neuroblastoma?(Ans- HMA and VMA
what is the left adrenal gland vein drainage? right adrenal gland vein drainage? to what veins is this system similar to?(Ans- left adrenal vein--> left renal vein--> IVC; right adrenal vein--> IVC; gonadal veins
what are the two components of the pituitary? what are there embryological derivatives? which makes the majority of the pituitary?(Ans- adenohypophysis and neurohypophysis; oral ectoderm (rathkes pouch) and neuroectoderm; adenohypophysis
- / 4
what two neuropeptides do the neurohypophysis secrete? where are these neuropeptides made? where do the cells in the neurohypophysis come from?(Ans- vasopressin (ADH) and oxytocin; in the neurons in the supraoptic and paraventricular nuclei (Neuropeptides); they are the cell bodies of neurons in the hypothalamus (one and the same!)
what are neurophysins?(Ans- carrier proteins in the posterior pituitary that carry the ADH and oxytocin hormones in circulation
what does the adenohypophysis secrete?(Ans- FSH, LH, prolactin, GH, ACTH, TSH, melanotropin
from what precursor is melanotropin made from? what else does this precursor make?(Ans- POMC; ACTH
what type of cells make up the majority of the adenohyophysis and where are they located?(Ans- somatotrophs; centrally
what hormones have a common alpha subunit? what differentiates them and how?(Ans- TSH, LH, FSH, hCG; a beta unit which determines the hormones specificity
what is the most common pituitary adenoma? what kind of cells are these?(Ans- prolactinoma; acidophils
which cells in the adenohypophysis are acidophils?(Ans- prolactin and Growth hormone producing cells
- / 4
what cells in the adenohypophysis are basophils? all of these cells produce hormones with what common subunit? what is the exception?
(Ans- B-FLAT: basophils- FSH, LH, ACTH, TSH; alpha; ACTH
T/F the neurohypophysis receives less blood from the hypophysial portal system than adenohypophysis (Ans- true
what are the endocrine pancreas cell types and what do they produce?how are they organized?(Ans- alpha (glucagon), beta (insulin), and somatostatin; into islets of langerhans which are collections of these cells- with beta central (INsulin INside) and alpha cells peripheral and somatostatin cells interspersed
from where do the islets arise from? and where in the pancreas are the islets most abundant?(Ans- pancreatic buds; in the tail of the pancreas
what would be the symptoms of a somatostatinoma? where would it most likely arise from?(Ans- gallbladder stones (inhibition of CCK!), achlorydia (inhibition of gastrin!) steatorrhea and constipation; from the pancreas
what would be the main symptom of an insulinoma?(Ans- hypoglycemia
what would be the main symptom of a VIPoma? where would it be located?(Ans- diarrhea, hypotension, metabolic acidosis, hypokalemia
what other cells hormones are secreted from the endocrine pancreas (other than insulin, glucagon, somatostatin)?(Ans- gastrin (gastrinoma!), VIP (vipoma!) from pancreatic polypeptide (pp) secreting cells
- / 4