Endocrinology Flashcards
Connection of thyroid to tongue
thyroglossal duct (foramen cecum= normal remnant)
Where thyroid diverticulum arise
primitive pharynx
Layers and products of adrenal medulla
Zona glomerulosa: Aldosterone
Zona fasciculata: cortisol
zona reticularis: sex hormones
Common tumors of adrenal medulla in adults vs kids
adults: pheo
kids: neurobalstoma (HTN uncommon)
Venous drainage of L vs R adrenal gland
L: L adrenal vein, L renal vein, IVC
R: R adrenal vein, IVC
Rathke pouch- what does it become
Anterior pituitary
Secreted by posterior pituitary
vasopressin, oxytocin
secreted by anterior pituitary
FSH, LH, ACTH, TSH (Basophils)
prolactin, GH (Acidophils)
a cells of pancrease: secreted and location
glucagon, peripheral
b cells of pancreas: secreted and location
insulin, central
delta cells of pancreas: secreted and location
somatostatin, interspersed
Insulin R is a ___
tyrosine kinase
pathways induced by insuline receptor
PI3 kinase, RAS/MAP kinase
Gluc transporter in adipose tissue, skeletal muscle
GLUT-4 (insulin dependent)
Gluc transpoter in RBC, brain, cornea
GLUT-1 (insulin independent)
Gluc transporter in spermatocytes, GI tract
GLUT-5 (Fructose, insulin independent)
Gluc transporter in b islet, liver, kidney, SI
GLUT-2 (bidirectional, insulin independent)
What inhibits glucagon?
insulin, hyperglycemia, somatostatin
what is the action of glucagon?
glyocgenolysis, gluconeogenesis, lipolysis, ketone production
Effect of CRH
incr ACTH, MSH, b-endorphin
Effect of dopamine on pituitary
decr prolactin
Effect of Prolactin on pituitary
decr GnRH
Affect of somatostatin on pituitary
decr GH, TSH
Effect of TRH on pituitary
Incr TSH, prolactin
Effect of GnRH on pituitary
Tonic: supresses HPA
Pulsatile: puberty, fertility
via FSH, LH
Bromocriptine
Dopamine agonist, used to inhibit prolactin secretion
what stimulates prolactin secretion
dopamine antagonists (antipsychotics), estrogens
What 2 factors inhibit GH
glucose, somatostatin
What mediates GH effects
IGF-1/somatomedin
Which nucleus synthesizes ADH
supraoptic nuclei of hypothalamus
What is treatment of central DI
desmopressin (ADH analog)
What receptors sense ADH, what to they regulate?
V2- serum osmolarity (primary function)
V1- blood pressure
mineralocorticoid, cortisol, sex hormone levels in 17a-hydroxylase deficiency
incr mineralocorticoid, decr cortisol, decr sex hormone levels
mineralocorticoid, cortisol, sex hormone levels in 21-hydroxylase deficiency
decr mineralocorticoid, decr cortisol, incr sex hormone levels
mineralocorticoid, cortisol, sex hormone levels in 11b-hydroxylase deficiency
decr mineralocorticoid, decr cortisol, incr sex hormone levels; incr BP due to incr 11-deoxycorticosterone
Presents as hypertension, hypokalemia, lack secondary sexual development in females
17a hydroxylase deficiency
Presents as hypotension, hyperkalemia, incr renin; salt wasting in infants, precocious puberty in children
21 hydroxylase deficiency
presents as hypertension with low renin, virilization in females
11b hydroxylase deficiency
Functions of cortisol (BIG FIB)
INCR: Blood pressure Insuline resistance Gluconeogensis, lipolysis, proteolysis DECR: Fibroblast activity Inflammatory response Bone formation
What are patients on exogenous cortisol susceptible to? what is mechanism
TB, candidiasis; blocked IL-2 production
Regulation of cortisol secretion
CRH produced by hypothalamus, ACTH produced by pituitary
Cells that produce PTH
chief cells of parathyroid
Effect of PTH on bone
incr resorption of Ca2+, PO43-
Effect of PTH on kidney (3)
incr reabsoprtion Ca2+ DCT
decr reabsorption PO43- in PCT
incr production calctriol
Effect of Mg on PTH levels
moderate decreae Mg: incr PTH
severe decrease Mg: decr PTH
Causes if hypomagnesemia: diarrhea, aminoglycosides, diuretics, alcohol abuse
Effect of incr pH on Ca levels
incr affinity to albumin, symptoms of hypocalcemia
Source of calcitonin
Parafollicular C cells of thyroid
T3 functions (4 Bs)
Brain maturation
Bone growth (synergize with GH)
B-adrenergic effects (incr B1 on heart)
Basal metabolic rate
Cushing disease vs cushing syndrome
Cushing Disease= ACTH secreting pituitary adenoma
Cushing syndrome= incr cortisol (multiple causes)
Cushing syndrome with low ACTH, diagnostic test
primary adrenal adenoma, hyperplasia, or carcinoma; MRI to confirm tumor; expect atrophy of uninvolved gland
Cushing syndrome with high ACTH, suppression via high dose dexa
Cushing disease, usually pituitary adenoma