Term
| What are leptin's origins and effects? |
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Definition
Secreted by adipose tissue, directly related to mass
Reflects well fed state, changes over days, not immediately.
Reduces food intake through CNS JAK-STAT pathway
Increases basal metabolic rate
Inhibits insulin secretion and synthesis |
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Term
| What are the functions of cortisol? |
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Definition
| Since cortisol is a glucocorticoid, its aim is to increase the level of glucose in the blood. So, it antagonizes insulin. It promotes gluconeogenesis, lipolysis, and proteinolysis. It also downregulates immune function and bone formation. |
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Term
| What do osteoblasts secrete in response to PTH? |
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Definition
RANK-L, NFkB ligand that along with IL-1 activates reabsorption
M-CSF, critical for osteoclast differentiation |
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Term
| What metabolite in the urine is used to measure PTH mediated bone reabsorption? |
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Definition
| Hydroxyproline, which is generated from the metabolism of collagen, which makes the bone network. |
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Term
| Relationship between PTH and cAMP in the urine? |
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Definition
| Since PTH exerts its effects int the kidney by activating adenylate cyclase at the luminal cell membrane of kidney cells, it results in increased cAMP secretion into the urine. |
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Term
| What are PTHs effects on phosphate, bicarb, Mg, Ca? |
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Definition
Increase reabs. of Mg, Ca at the distal conv tubule.
Inc. secretion of phosphate, and bicarb |
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Term
| What are the effects of ghrelin? |
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Definition
Opposes leptin --> food seeking via PNS vagus and hypothalamus arcuate nucleus
increases cortisol, GH, ACTH, and prolactin |
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Term
| How does vitamin D increase interstitial Ca? |
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Definition
| Basically, vitamin D is converted into activated OH2 vit D in the kidney by the enzyme 1 hydroxylase, which increases Ca absorption because it acts as a hormone, and increases uptake of Ca into interstitial tissue from the gut and from bone. |
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Term
| What is the result of addison's disease? |
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Definition
| In addison's disease, not enough cortisol is produced. And sometimes the production of mineralocorticoids also diminishes. |
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Term
| What clear effect on the skin is a result of addisons? |
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Definition
| Hyperpigmentation is commonly seen in addisons because ACTH is produced in high amounts, but the adrenal gland does not respond to it by producing cortisol, which would negatively feedback on the ACTH normally. Excessive ACTH production in the hypothalamus results in oversecretion of melanocyte stimulating hormone, which causes oversecretion of melanin by melanocytes, leading to hyper pigmentation. |
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Term
| What are the symptoms associated with addisons? |
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Definition
GI probs: diarrhea, constipation
fluid and electrolyte imblance: hyponatremia, hyperkalemia, and hypotension due to volume contraction |
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Term
| What is the diagnostic test used for addisons? |
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Definition
ACTH stimulation test, after which in a normal person cortisol secretion increases. In a patient with adrenal insufficiency, their adrenal glands do not respond to ACTH, and so their cortisol levels do not increase.
Another diagnostic test is by administering metyrapone. This enzyme inhibits cortisol production, which by lack of negative feedback should increase levels of ACTH and 11-deoxycortisone. In patients with adrenal insufficiency, ACTH increases but 11-deoxycortisone doesn't. |
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Term
| How do you differentiate secondary adrenal insuffiency from primary? |
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Definition
| Primary is addisons, meaning something is wrong with the adrenal gland itself. Secondary is due to insufficient levels of ACTH, in which case in the ACTH stimulation test, cortisol would increase. In the metyropone test, no increase in ACTH. Also, there is no hyperpigmentation observed in secondary. |
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Term
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Definition
multiple endocrine neoplasia II
medullary thyroid carcinoma
pheochromocytoma
primary hyperparathyroidism |
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Term
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Definition
multiple endocrine neoplasia III
medullary thyroid carcinoma
pheochromocytoma
Mucosal neuroma
marfanoid body habitus NOT marfan disorder |
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