Flashcards in Endocrine Deck (138)
Which endocrine hormones are IP3 linked? T/F: Hormones from the posterior pituitary are IP3-linked.
GGOAT "butts" you:
Oxytocin / ADH are from the posterior pituitary and are IP3-linked.
Which endocrine hormones are cAMP linked? (12)
calcitonin / GHRH / glucagon too!
Hormones in the anterior pitiutary tend to be linked to which signaling pathway? Can you name 4?
cAMP. These include FSH, LH, ACTH, TSH.
Endocrine hormones which signal through steroid receptors (6):
Vitamin D, Estrogen, Testosterone, T3/T4, Cortisol, Aldosterone, Progesterone
Effect of too much SHBG in men? Too little in women?
Men: Gynecomastia with high SHBG.
Women: Hirsutism with low SHBG.
What kind of signaling path does prolactin use?
What kind of signaling path does oxytocin use?
What signaling path does insulin use?
GH is secreted from:
Glucocorticoids are secreted from:
The adrenal cortex, zona fasciculata
Progesterone is secreted from (2):
Prolactin comes from the:
Oxytocin comes from the:
Glucagon comes from the:
Insulin comes from:
Somatostatin comes from:
Glucagon from alpha cells of pancreas
Insulin from beta cells
Somatostatin from delta cells
FSH comes from the:
Vasopressin (ADH) comes from:
The hypothalamus (supraoptic nucleus), is stored in the posterior pituitary
TSH comes from the:
Estradiol comes from the:
Estriol comes from the:
Estrone is made by:
Lutenizing hormone comes from the:
Mineralocorticoids / aldosterone comes from the:
Zona glomerulosa of the adrenal cortex
ACTH is excreted by the:
This molecule is the precursor to ACTH, lipotropins, MSH, and the beta-endorphins:
Four main causes of hyperprolactinemia:
1. Pregnancy / nipple stimulation
4. Dopamine antagonists
Where is somatostatin made?
In the GI tract, mostly D cells in gut mucosa, pancreatic delta cells make it too.
What does somatostatin do?
Inhibits secretion of GI hormones, decreases endocrine / exocrine secretion, reduces GI motility and GB contraction.
Three somatostatin analogues that are used clinically:
In the fetus, this hormone is secreted late in gestation and is responsible for lung maturation:
Most common tumor of adrenal medulla in adults:
Most common tumor of adrenal medulla in chidren:
T/F this tumor causes episodic HTN.
Neuroblastoma. Does not cause episodic HTN.
The posterior pituitary is derived from this tissue layer:
The anterior pituitary is derived from this tissue in embryonic development:
Surface ectoderm (Rathke's pouch)
Hormones secreted by the anterior pituitary:
FSH, LH, ACTH, TSH, prolactin, GH, MSH
There are three cell types in the islets of the pancreas. What are they, where are they, and what do they make?
a on the outside make glucagon
b on the INSide make INSulin
d are throughout and they make somatostatin
The adrenal cortex is derived from this germ layer:
The adrenal medulla derives from this cell lineage:
Is it the L or R adrenal vein that drains directly into the IVC?
The R. The left drains into the L renal vein then to the IVC.
What are the three zones of the adrenal cortex?
This zone of the adrenal cortex is under control of the renin-angiotensin system.
The glomerulosa, this is where aldosterone is made.
Zone of the adrenal cortex that makes cortisol:
Where does the thyroid gland come from?
Floor of the pharynx, it descends into the neck and leaves behind the foramen cecum = remnant of the thyroglossal duct.
The hypothalamus releases this hormone to stimulate prolactin release. What other hormone is stimulated by this substance?
TRH causes prolactin and TSH release from the anterior pituitary
This molecule released from the hypothalamus causes ACTH, MSH, and b-endorphin release from the anterior pituitary:
This hormone inhibits GH release from the anterior pituitary:
Somatostatin inhibits these two hormones:
What happens if you give someone a good whopping dose of GnRH?
GnRH in a steady dose will inhibit LH and FSH. It is PULSATILE secretion that drives FSH and LH production.
What effect does prolactin have on GnRH?
Inhibits its release
ACTH is released from the anterior pituitary in response to two major things:
1. CRH from the hypothalamus
T/F: You would measure growth hormone levels to dx acromegaly.
F. Measure IGF-1.
T/F: GH increases insulin resistance.
Two things inhibit the secretion of growth hormone:
5 main effects of cortisol on the body:
1. Maintains BP (increase in a1 receptors)
2. Decreases bone formation
4. Insulin resistance
5. Increases energy release (gluconeogenesis, lipolysis, proteolysis)
Primary adrenal insufficiency is defined as decrease in cortisol secondary to what kind of difficulty?
Secondary and tertiary, where are they?
Primary adrenal insufficiency = problem with the adrenal gland itself.
Secondary = problem with the pituitary.
Tertiary = problem with the hypothalamus.
How is iodine transported into cells?
Sodium gradient is used to drive it in.
This hormone binds most of the thyroid hormone in the blood:
When would you see TBG decreased? Increased?
TBG is decreased in hepatic failure, increased in pregnancy and OCP use (estrogen upregulates it).
The enzyme that converts T4 -> T3:
This drug works both to inhibit thyroid synthesis and to inhibit the conversion of T4 to T3:
This anti-thyroid drug works only to inhibit the conversion of one thyroid hormone precursor to another. What is the enzyme this drug inhibits? The other drug that has the same effect?
Methimazole inhibits peroxidase, PTU works here too.
If you give someone a crazy excess of I2 you may see a paradoxical decrease in T4 production. What is this effect called?
This thyroid hormone feeds back to the anterior pituitary to cause a decrease in sensitivity to TRH:
Thyroid hormone upregulates which adrenergic receptors?
b1, responsible for increase in cardiac contractility, HR, and stroke volume.
What hormone is elevated in Cushing syndrome?
What is Cushing disease?
Hypercortisol state 2/2 pituitary adenoma (ACTH-secreting pituitary tumor)
Second most common cause of Cushing syndrome:
Ha! Trick question!
Most common: Iatrogenic
Second: Pituitary adenoma
Third: Ectopic ACTH-producing tumor
Dexamethasone suppression test: In what case will a low dose of dex suppress cortisol? A high dose? When will there be no suppression?
Low dose suppresses a normal pituitary.
High dose suppresses a pituitary tumor.
Failure to suppress = the thing makes what it wants anyway without any input, ie it is an ectopic source of ACTH (lung CA) or an adrenal tumor making cortisol directly.
How do you tell an ectopic ACTH-producing tumor from an adrenal tumor making cortisol?
The ectopic tumor (usually small cell lung CA, bronchial carcinoid) will make ACTH. The adrenal tumor doesn't.
What hormone is affected in Conn syndrome?
Conn syndrome = primary hyperaldosteronism
What is primary hyperaldosteronism caused by?
Primary hyperaldo = Conn syndrome = adrenal problem.
Secondary hyperaldo = overactivity of the RAA system (such as one kidney receiving low blood flow and flooding the system with renin)
T/F: Conn syndrome is associated with high plasma renin.
F. Renin is low, kidneys know they are getting enough blood and that there is HTN. Renin is high in secondary hyperaldosteronism.
Tx for Conn syndrome:
1. Remove tumor
2. Spironolactone or epleronone (K+ sparing)
Hypertension / salt retention, low potassium, met. alkalosis... first thing that should come to mind:
What effect should a rise in serum potassium have on aldosterone?
Should stimulate it, want to dump the K+
Hormone affected in Addison disease:
Aldosterone and cortisol
Most common cause of Addison disease:
T/F: The medulla of the adrenal gland is affected in Addison disease:
F. All three layers of the cortex get hit, but the medulla is untouched.
What is secondary adrenal insufficiency?
Secondary adrenal insufficiency occurs at the level of the pituitary.
In which case of adrenal insufficiency -- primary or secondary -- would you see skin hyperpigmentation and why?
Primary = problem with the gland = pituitary making loads of ACTH = POMC activation and MSH made = skin hyperpigmentation. Secondary = pitutary failure, no ACTH, no skin pigmentation.
What is tertiary adrenal insufficiency, and what usually causes it?
Tertiary adrenal insufficiency = HTH thinking there is still cortisol when there is not, ie in cases of steroid w/d that are too abrupt. HTH will make no CRH, so the pituitary will make no ACTH, so you get no cortisol / aldo. Need to taper.
Metabolic abnormalities in Addison disease:
Hyponatremic volume contraction, hyperkalemia, acidosis.
In secondary adrenal insufficency, do you see hyperkalemia?
No! There is no ACTH, but your adrenals still make aldosterone, so salt / H2O / K+ balance is normal.
With what three syndromes are pheochromocytomas associated?
Medical treatment of a pheo prior to surgical removal?
a-block first: Phenoxybenzamine or phentolamine, then follow with b-block. Don't want to b-block first, you leave Epi unopposed in the body to hit a1 receptors and cause through the roof HTN.
Pheochromocytomas can secrete epo. Three other tumors that do this:
Renal cell CA
Most common tumor of adrenal medulla in adults? Kids?
Pheo in adults, adrenal neuroblastoma in kids.
Which oncogene is implcated in adrenal neuroblastoma?
T/F: A pheo can calcify
T. Rule of 10's:
10% calcified, malignant, bilateral, extra-adrenal, and 10% in kids.
HLA associated with Hashimoto thyroiditis (2):
Endocrine disease that is a risk for B cell lymphoma:
Severe fetal hypothyroidism, 5 Ps in addition to the mental retardation and FTT:
HLA type associated with de Quervain's thyroiditis:
What is Reidel's thyroiditis? What do you see in there histologically?
Replacement of the thyroid with fibrous tissue. See macrophages and eosinophils in fibrous base.
Name for what happens when you give someone with a goiter or excess thyroid tissue who is iodine deficient a ton of iodine suddenly:
Three things that can cause Jod-Basedow:
Ppl w/ Graves who are iodine deficient getting iodine suddenly
Which anti-thyroid agent is preferred in pregnancy?
PTU. Methymazole causes fetal cutis aplasia.
Both PTU and methimazole cause this problem with WBCs:
T/F: PTU, the preferred anti-thyroid drug in pregnancy, crosses the placenta:
Tx for thyroid storm:
b-block aggressively, PTU
Autoimmune thyroid disease with thyroid stimulating Ab? With thyroid destruction?
HLA subtypes associated with Graves disease:
Most common thyroid cancer:
Thyroid cancers with RET mutations:
Thyroid cancer with Ras mutation:
Thyroid cancer that likes to spread hematogenously:
Sheets of cells in an amyloid base, hyperthyroidism:
Medullary thyroid CA
Disease in which you see an increased resin radioactive T3 uptake:
Graves. TBG is all occupied by endogenous thyroid hormone, give people a radiolabeled one and everything you give them will bind your test resin.
This teratoma has functional thyroid tissue:
Struma ovarii teratoma
Treatment for acromegaly:
Resect pituitary if you can
Octreotide or other somatostatin analogue
Three ways of diagnosing acromegaly:
1. High serum IGF-1
2. Fail to suppress GH with oral glucose
3. Mass on MRI
What is Sheehan's syndrome?
Postpartum bleeding drops BP so much that the pituitary gets damaged, can be any hormone affected. Most commonly presents with failure to lactate.
GH excess is called _____ in adults but is called _____ in children.
Common presentation of MEN 1:
Renal stones (hyper PT)
Ulcers in the stomach (ZE or another pancreatic endocrine tumor)
MEN 1 tumors:
MEN 2A and 2B tumors:
Medullary thyroid cancer & pheo in both.
2A = parathyroid
2B = mucosal neuromas, marfanoid habitus
MEN associated with 11q13
MEN syndromes associated with a problem on chromosome 10:
MEN 2 (RET)
What form of inheritance do all the MEN syndromes share?
Glucocorticoid medication that is virtually the same molecule as cortisol:
This drug is used in the treatment of aldosterone deficiency. Why?
This drug has the highest mineralocorticoid effect of all the glucocorticoids.
How do the glucocorticoids work to decrease the production of leukotrienes and prostaglandins?
They block phospholipase A2 and inhibit COX-2.
T/F: Empty sella syndrome is most often sub-clinical.
T, usually there is some pituitary tissue glued to the sella somewhere. Can present with any deficiency.
These hormones share a common alpha sub-unit:
TSH, LH, FSH, b-HCG
This hormone increases blood glucose level and decreases protein synthesis:
These two cancers are associated with RET gene mutations:
Medullary thyroid cancer
Four clinical uses for somatostatin:
Inhibits GH, TSH, ACTH
Decreases sphlancnic circ. (can help control bleeding)
Tones down GI endocrine excess
Can be used for refractory diarrhea
Thyroid cancer associated with RAS or PAX8-PPAR gamma:
Thyroid cancer associated with RET or NTRK1:
Papillary thyroid CA
Thyroid cancer associated with BRAF:
Starting molecule for steroid synthesis:
Cholesterol is converted to pregnolone, first step of steroid synthesis, by this enzyme. What drug inhibits this enzyme?
Ketoconazole inhibits desmolase
From pregnenolone, in order to make aldosterone, you need to first make this molecule. What is the enzyme?
To get to mineralocorticoids, you make progesterone with 3b-OH dehydrogenase.
What is the one arm of the steroid synthesis path that does not require 17a-hydroxylase?
Synthesis of mineralocorticoids, eg aldosterone.
What is the one arm of the steroid synthesis path that does not require 21-hydroxylase?
Synthesis of sex hormones.
Precursor molecule to the synthesis of sex hormones:
DHEA, which is made into androstenedione.
What is the main difference between 21-hydroxylase and 11b-hydroxylase deficiency?
The paths are really very close together. 11b-hydroxylase acts a little later in the path, so you get one extra product backing up. This product is 11-deoxycorticosterone, which causes HTN. Both syndromes = high sex hormones, 11b also has HTN.
Mnemonic involving 1's for adrenal steroid synthesis:
1 in the first digit = HTN
1 in the second digit = masculinization