TRH stimulates which 2 hormones?
TSH, Prolactin
Dopamine inhibits which hormone?
Prolactin
CRH stimulates which 3 hormones?
ACTH, MSH, beta-endorphin
GHRH stimulates which hormone?
GH, TSH
GnRH stimulates which 2 hormones?
FSH, LH
Prolactin inhibits which hormone?
GnRH
How does prolactin inhibit ovulation in females and spermatogenesis in males?
By inhibiting GnRH synthesis and release
How does prolactin inhibit its own secretion?
Increasing dopamine synthesis and secretion from the hypothalamus
Does TRH inc/dec prolactin secretion?
Inc
Bromocriptine is a _____ agonist that can be used in the treatment of _____.
Dopamine; prolactinoma
Dopamine antagonists (antipsychotics) and _____ stimulate prolactin secretion.
Estrogens (OCPs, pregnancy)
GH stimulates linear growth and muscle mass through _____ secretion.
IGF-1/somatostatin
Does GH inc/dec insulin resistance?
Inc
T/F: GH is release in pulses in response to GHRH and secretion is inc during exercise and sleep.
TRUE
Excess secretion of GH causes _____ in adults or _____ in children.
Acromegaly; gigantism
State whether mineralocorticoids, cortisol, sex hormones inc/dec in 17 alpha-hydroxylase deficiency.
Inc, dec, dec
How does an XY with 17 alpha-hydroxylase deficiency present?
HTN, hypokalemia. Dec DHT leads to pseudohermaphroditism (variable, ambiguous genitalia; undescended testes)
How does an XX with 17 alpha-hydroxylase deficiency present?
HTN, hypokalemia. Externally phenotypic female with normal internal sex organs, lacks secondary sex characteristics
State whether mineralocorticoids, cortisol, sex hormones inc/dec in 21-hydroxylase deficiency.
Dec, dec, inc
How does a patient with 21-hydroxylase deficiency present?
Hypotension, hyperkalemia, inc renin activity, volume depletion. Masculinization, leading to pseudohermaphroditism in females.
State whether mineralocorticoids, cortisol, sex hormones inc/dec in 11 beta-hydroxylase deficiency.
Mineralocorticoids: dec aldosterone, inc deoxycorticosterone; dec; inc
How does a patient with 11 beta-hydroxylase deficiency present?
HTN, masculinization
T/F: All congenital adrenal enzyme deficiencies are characterized by an enlargement of both adrenal glands due to inc ACTH stimulation because of dec cortisol.
TRUE
Name 5 functions of cortisol.
1) Maintains Blood pressure 2) Dec Bone formation 3) Anti-Inflammatory/Immunosuppressive 4) Inc Insulin resistance 5) Inc Gluconeogenesis (*Remember BBIIG mnemonic!)
T/F: Chronic stress induces prolonged cortisol secretion.
TRUE
PTH is made by the _____ cells of the _____.
Chief, parathyroid
Does PTH inc/dec bone resorption of calcium and phosphate?
Inc
Does PTH inc/dec kidney reabsorption of calcium in the distal convoluted tubule?
Inc
Does PTH inc/dec reabsorption of phosphate in the proximal convoluted tubule?
Dec
Does PTH inc/dec 1,25-(OH)2D3 (calcitriol) production by stimulating kidney 1alpha-hydroxylase?
Inc
State whether PTH inc/dec the following: Serum Ca2+, serum (PO4)3-, urine (PO4)3-
Inc, dec, inc
PTH increases the production of M-CSF and RANK-L in _____, stimulating _____.
Osteoblasts; osteoclasts
A dec in serum Ca2+ will inc/dec PTH secretion.
Inc
A dec in serum Mg2+ will inc/dec PTH secretion.
Inc
A large dec in serum Mg2+ will inc/dec PTH secretion.
Dec
What are some common causes of dec Mg2+?
Diarrhea, aminoglycosides, diuretics, alcohol abuse
Vitamin D2/D3 is from sun exposure in skin while vitamin D2/D3 is ingested from plants.
D3; D2
Vitamin D2 and D3 are both converted to 25-OH in the _____ and to 1,25-(OH)2 (active form) in the _____.
Liver; kidney
Vitamin D inc/dec absorption of dietary Ca2+ and (PO4)3- and inc/dec bone resorption of Ca2+ and (PO4)3-
Inc; inc
Inc/dec PTH, inc/dec Ca2+, and inc/dec (PO4)3- cause inc 1,25-(OH)2 production.
Inc, dec, dec
Calcitonin is made by the _____ cells of the _____.
Parafollicular; thyroid
What is calcitonin’s function?
Dec bone resorption of calcium
How is calcitonin regulated?
Inc in serum Ca2+ causes calcitonin secretion
Name the hormones associated with the cAMP signaling pathway.
FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2 receptor), MSH, PTH, calcitonin, GHRH, glucagon (*Remember FLAT ChAMP mnemonic!)
Name the hormones associated with the cGMP signaling pathway.
ANP, NO (EDRF) (*Think vasodilators)
Name the hormones associated with the IP3 signaling pathway.
GnRH, GHRH, Oxytocin, ADH (V1 receptor), TRH, histamine, angiotensin II, gastrin (*Remember GGOAT mnemonic!)
Name the hormones associated with the steroid receptor signaling pathway.
Vitamin D, Estrogen, Testosterone, T3/T4, Cortisol, Aldosterone, Progesterone (*Remember VETTT CAP mnemonic)
Name the hormones associated with the intrinsic tyrosine kinase signaling pathway.
Insulin, IGF-1, FGF, PDGF, EGF (*MAP kinase pathway, think growth factors)
Name the hormones associated with the receptor-associated tyrosine kinase signaling pathway.
Prolactin, Immunomodulators (eg. Cytokines, IL-2, IL-6, IL-8, IFN), GH (*JAK/STAT pathway. Think acidophiles and cytokines. Remember PIG mnemonic!)
Steroid hormones are lipophilic, so they must do what in order to increase their solubility?
Must circulate bound to specific binding globulins
In men, how does an increase in sex hormone-binding globulin clinically present?
Gynecomastia (because free testosterone is lowered)
In women, how does an decrease in sex hormone-binding globulin clinically present?
Hirsutism (because free testosterone is raised)
What are the 4 B’s of thyroid function?
Brain maturation, bone growth, beta-adrenergic effects, and increased basal metabolic rate
_____ binds most T3 and T4 in the blood.
Thyroxine-binding globulin
Thyroxine-binding globulin is inc/dec in pregnancy or OCP use and inc/dec in hepatic failure
Inc, dec
Does T3 or T4 bind receptors with greater affinity?
T3
What is the Wolff-Chaikoff effect?
Excess iodine temporarily inhibits thyroid peroxidase which leads to decreased iodine organification which leads to decreased T3 and T4 production
What is the enzyme responsible for oxidation and organification of iodide as well as coupling of MIT and DIT?
Peroxidase
What is the difference between propylthiouracil and methimazole?
Propylthiouracil inhibits both peroxidase and 5’-deiodinase while methimazole inhibits peroxidase only
