Endocrine Flashcards
insulin cascade on skeletal muscle/fat cells
- binds to receptor (tyrosine kinase activity) –> Pi3K leads to inc GLUT 4 transporters and glycogen, protein and lipid synthesis
- RAS/MAP kinase pathway leads to cell growth and DNA synthesis
GLUT 4 receptors on
skeletal muscle and adipose tissue
GLUT 1 receptors on
RBCs, brain, cornea
GLUT 5 receptors on
spermatocytes, GI tract
GLUT 2 receptors on
B islet cells, liver, kidney, small intestine
glucagon made in the
alpha cells of the pancreas
CRH function
increases ACTH, MSH, B-endorphin
- all these hormones are created through cleavage of POMC
- B endorphin is a pentapeptide that binds to delta and mu receptors
prolactin function
- decreased GnRH secretion
- prolactin itself is inhibited by dopamine
somatostatin function
- decreases GH and TSH secretion
TRH function
increases TSH and prolactin secretion
ADH/Diabetes insipidus
- synthesized in the hypothalamus
- permanent DI occurs when there is damage to the hypothalamus
- nephrogenic doesnt respond to ADH, central does
cortisol mechanism of increasing blood pressure
- upregulates alpha receptors on arterioles –> increases sensitivity to norepi and epi
PTH secreted by
chief cells of parathyroid
low Mg’s effect on PTH
decreased Mg increases PTH
severely decreased Mg decreases PTH
calcitonin secreted by
parafollicular cells in the thyroid
hormones that use cAMP signalling pathway
FLAT ChAMP
- FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2 receptor), MSH, PTH, calcitonin, GHRH and glucagon
hormones that use cGMP pathway
NO and ANP
hormones that use IP3 pathway
GOAT HAG
- GH, oxytocin, ADH (V1 receptor), TRH, histamine, ang II, gastrin
hormones that act on intrinsic tyrosine kinase receptors
insulin, IGF-1, FGF, PDGF, EGF
hormones that act on receptor associated tyrosine kinases
prolactin, immunomodulators (IL-2, 6, 8, IFN) and GH
PIG
enzyme responsible for oxidation of iodine, iodination of TG and MIT/DIT coupling
thyroid peroxidase
thyroglossal duct cyst
anterior midline neck mass that moves with swallowing or protrusion of the tongue
most common tumor of the adrenal medulla in kids vs. adults
neuroblastoma vs. pheo
post pit
ADH and oxytocin
- derived from neuroectoderm
- hormones produced in the thalamus, moved to the post pit by neurophysins
ant pit
ACTH, GH, TSH, FSH, LH, MSH, prolactin
- derived from oral ectoderm (Rathke pouch)
secondary hyperaldosteronism
- due to renal perception of low intravascular volume (overactive RAAS)
- renal artery stenosis, CHF, cirrhosis, nephrotic syndrome
- treat with spironolactone
Waterhouse-Friderichson syndrome
acute primary adrenal insufficiency associated with Neisseria meningitidis septicemia, DIC and endotoxic shock
Neuroblastoma
- most common adrenal medulla tumor in kids
- arises from neural crest cells
- firm, irregular mass that can cross the midline
- inc HVA, assocaited with n-myc oncogene
pheo
- associated with VHL, MEN 2A and 2B, NF1
- increased urinary VMA
- treat with irreversible alpha agonist (phenoxybenzamine) and beta blockers before resection
Hashimoto Thyroiditis
- most common cause of hypothyroidism in iodine sufficient areas
- anti-thyroid peroxidase, anti-microsomal and anti-thyroglobulin Abs
- may be hyperthyroid early in the course
- histo: Hurthle cells, lymphoid aggregate with germinal centers
- moderately enlarged, non-tender thyroid
Subacute/de Quervain/granulomatous thyroiditis
- self limited following flu-like illness
- may be hyperthyroid early in course
- histo: granulomatous inflammation
- inc ESR, jaw pain, VERY tender thyroid
Reidel thyroiditis
- thyroid replaced by fibrous tissue, may extend into local tissues, mimicking anaplastic carcinoma (but this is in young people)
- IgG2 related systemic disease
- fixed, hard, rock-like thyroid
Wolff-Chaikoff effect
- excess iodine temporarily inhibits thyroid peroxidase –> decreased iodine organification –> decreased T3/T4 production
toxic multinodular goiter
focal patches of hyperfunctioning follicular cells independent of TSH due to mutation in TSH receptor
- hot nodules are rarely malignant
Jod-Basedow phenomenon
- thyrotoxicosis if a pt with iodine deficiency goiter is made iodine replete
papillary thyroid carcinoma
- most common, excellent prognosis
- orphan annie nuclei (empty appearing), psammoma bodies, nuclear grooves
- inc risk with RET and BRAF mutations, childhood irradiation
follicular thyroid carcinoma
- good prognosis, invades thyroid capsule (unlike adenoma)
- spreads hematogenously
medullary thyroid carcinoma
- from parafollicular C cells in an amyloid stroma
- calcitonin
- associated with men 2A and 2B
pseudohypoparathyroidism
- Albright hereditary osteodystrophy
- AD unresponsiveness of kidney to PTH (end organ resistance to PTH due to Gs mutation)
- hypocalcemia, shortened 4th/5th digits, short stature
treatment for acromegaly
somatostatin analogs - octreotide
or GH receptor antagonist - pegvisomant
treatment for nephrogenic vs. central DI
- central: DDAVP and hydration
- nephrogenic: HCTZ, indomethacin, amiloride and hydration
causes and treatment of SIADH
- causes: ectopic ADH (small cell lung cancer), CNS disorders/head trauma, pulmonary disease (COPD, pneumonia), drugs (cyclophosphamide)
- treat with fluid restriction, IV hypertonic saline, conivaptan, tolvaptan, demeclocycline
Whipple triad
- episodic CNS symptoms associated with insulinoma
- lethargy, syncope and diplopia
Zollinger-Ellison Syndrome
- gastrin secreting tumor of the pancreas or duodenum
- acid hypersecretion leads to ulcers in the duodenum and jejunum
- associated with MEN 1
MEN 1
diamond
- pituitary tumors (prolactin or GH)
- parathyroid tumors
- pancreatic endocrine tumors (Z-E, insulinomas, VIPomas, glucagonomas)
- commonly presents with kidney stones and stomach ulcers
MEN 2A
square
- parathyroid hyperplasia
- pheo (chromaffin cells)
- medullary thyroid carcinoma
- RET proto-oncogene
MEN 2B
triangle
- oral/intestinal ganglioneuromatosis (mucosal neuromas)
- pheo
- medullary thyroid carcinoma
- marfanoid habitus
- RET proto-oncogene
hormones that use steroid receptors
Vit D, Estrogen, Testosterone, T3/T4, cortisol, aldosterone, progresterone
VETTT CAP
