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Flashcards in endo Deck (68):
1

islet of langerhans organization

alpha -> glucagon = peripheral. beta -> insulin = central (insulin inside). delta -> somatostatin = interspersed

2

zona glomerulosa

control: renin-angiotensin system. product: aldosterone

3

zona fasciculata

control: ACTH, CRH. products: cortisol, sex hormones

4

zona reticularis

control: ACTH, CRH. products: sex hormones

5

adrenal medulla

chromaffin cells. control: preganglionic sympathetic fivers. product: catecholamines (epi, NE). pheochromocytoma: most common adult tumor. neuroblastoma: most common in kids - rarely -> HTN.

6

CRH

fxn: inc. ACTH, MSH, beta-endorphin. dec. w/exogenous steroid use

7

DA

fxn: dec. prolactin. DA antagonists can -> galactorrhea due to hyperprolactinemia

8

GHRH

fxn: inc. GH. analog (tesamorelin) used to Tx HIV-associated lipodystrophy

9

GnRH

fxn: inc. FSH, LH. regulated by prolactin. tonic GnRH suppresses HPA axis. pulsatile GnRH -> puberty, fertility

10

somatostatin

fxn: dec. GH, TSH. analogs used to Tx acromegaly

11

TRH

fxn: inc. TSH, prolactin

12

17alpha-hydroxylase deficiency

inc. mineralocorticoids, dec. cortisol, sec. sex hormones, inc. BP, dec. K, dec. androstenedione. presentation: XY: pseudo-hermaphroditism. XX: lack secondary sex development

13

21-hydroxylase deficiency

dec. mineralocorticoids, dec. cortisol, inc. sex hormones, dec. BP, inc. K, inc. renin, inc. 17-hydroxy-progesterone. most common. presents in infancy w/salt wasting or childhood w/precocious puberty. females = virilized.

14

11beta-hydroxylase deficiency

dec. aldosterone, inc. 11-deoxycorticosterone (inc. BP), dec. cortisol, inc. sex hormones, inc. BP, dec. K, dec. renin. XX: virilization

15

effect of inc. pH on ionized Ca

inc. affinity for albumin -> inc. % bound -> hypocalcemia

16

effects of vit D

= cholecalciferol. -> inc. absorption of dietary Ca and PO4 + inc. bone resorption -> inc. available Ca and PO4.

17

effects of PTH

inc. bone resorption of Ca and PO4. inc. kidney reabsorption of Ca in distal convoluted tubule. dec. reabsorption of PO4 in proximal convoluted tubule. inc. 1,25-(OH)2D3 (calcitriol) production by stimulating kidney 1alpha-hydroxylase in proximal convoluted tubule. stimulates osteoblasts to produce RANK-L to stimulate osteoclasts. PTH: Phosphate Trashing Hormone.

18

PTH regulators

+: dec. serum Ca, inc. serum PO4, dec. serum Mg. -: very low serum Mg.

19

vit D regulators

+: PTH, low [Ca], dec. PO4. -: 1,25-(OH)2D3

20

cAMP hormones

FLAT ChAMP: FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2-receptor), MSH, PTH, calcitonin, GHRH, glucagon

21

cGMP hormones

vasodilators: ANP, BNP, NO (EDRF)

22

IP3 hormones

GOAT HAG: GnRH, Oxytocin, ADH (V1-receptor), TRH, Histamine (H1-receptor), Angiotensin II, Gastrin

23

intracellular receptor hormones

VETTT CAP: Vit D, Estrogen, Testosterone, T3/T4, Cortisol, Aldosterone, Progesterone

24

intrinsic tyrosine kinase hormones

MAP kinase pathway: think grown factors: insulin, IGF-1, FGF, PDGF, EGF

25

receptor-associated tyrosine kinase

JAK/STAT pathway: think acidophils and cytokines: PIGGlET: Prolactin, Immunomodulators (e.g. cytokines IL-2, IIL-6, IFN), GH, G-CSF, Erythropoietin, Thrombopoietin

26

sex hormone binding globulin

inc. solubility of lipophilic steroid hormones. in men, inc. SHBG -> dec. free testosterone -> gynecomastia. in women, dec. SHBG -> inc. free testosterone -> hirsuitism. OCPs, pregnancy -> inc. SHBG, free estrogen remains unchanged.

27

T3 fxns

4Bs: Brain maturation, Bone grown, Beta-adrenergic effects, Basal metabolism.

28

wolf-chaikoff effect

excess iodine temporarily inhibits thyroid peroxidase -> dec. iodine organification -> dec. T3/T4 production

29

peroxidase

enzyme responsible for oxidation and organification of iodide + coupling of monoiodotyrosine (MIT) and di-iodotyrosine (DIT). inhibited by PTU (also inhibits 5'-deiodinase) and methimazole (peroxidase only)

30

neuroblastoma

originates from neural crest cells. homer-wright rosettes. occurs anywhere along sympathetic chain. typical presentation: firm, irregular mass, can cross midline (unlike wilms). opsoclonus/myoclonus syndrome (dancing eyes, dancing feet). homovanillic acid and VMA are inc. in urine. bombesin and neuron-specific enolase +. HTN uncommon. overexpression of N-myc.

31

pheochromocytoma rule of 10s

10% malignant, 10% b/l, 10% extra-adrenal (bladder wall), 10% calcify, 10% kids

32

pheo Tx

irreversible alpha-antagonists (e.g. phenoxybenzamine, to avoid causing HTN crisis) followed by beta-clockers prior to tumor resection.

33

lipids, myxedema in hypo/hyperthyroid

hypo: myxedema = facial/periorbital -> deep voice. hypercholesterolemia 2/2 dec. LDL receptor expression. hyper: myxedema = pretibial, periorbital. hypocholesterolemia + hyperglycemia

34

hasimotos

HLA-DR5. inc. risk of NH lymphoma (presents w/enlarging thyroid). Abs = markers, not mediators. histo: hurthle cells (pink cytoplasm), lymphoid aggregate w/germinal centers.

35

cretinism

6Ps: Pot-bellied, Pale, Puffy-faces, Protruding umbilicus, Protuberant tongue, Poor brain development.

36

riedel thyroiditis

thyroid replaced by fibrous tissue -> hypothyroid. fibrosis may extend to local structures (e.g. airway), mimicking anaplastic CA (but in a younger person). manifestation of IgG4-related systemic dz (e.g. autoimmune pancreatitis, retroperitoneal fibrosis, noninfectious aortitis). findings: fixed, rock-like, painless goiter

37

graves histo

hyperplasia, scalloping of the colloid

38

papillary CA

most common, excellent prognosis. "orphan annie eyes" cells (empty-appearing nuclei), psammoma bodies, nuclear grooves. lymphatic invasion = common. inc. risk w/RET and BRAF mutations + childhood irradiation

39

follicular CA

hematogenous spread. good prognosis. invades capsule (onlike follicular). uniform follicles. FNA isn't helpful for Dx: need excision.

40

medullary CA

from parafollicular C cells. produces calcitonin, sheets of cells in amyloid stroma. hematogenous spread common. associated w/MEN 2a/b (RET mutuations), warranting prophylactic thyroidectomy

41

peudohypoparathyroidism

albright hereditary osteodystrophy: AD. unresponsiveness of kidney to PTH. hypocalcemia, shortened 4th/5th digits, short stature. defect in Gs protein

42

familial hypocalciuric hypercalcemia

defective Ca-sensing receptor on parathyroid cells. PTH cannot be suppressed by inc. Ca level -> mild hypercalcemia w/normal to inc. PTH levels

43

osteitis fibrosa cystica

cystic bone spaces filled w/brown fibrous tissue = "brown tumor" consisting of deposited hemosiderin from hemorrhages -> bone pain.

44

hyperparathyroid Sx

stones, bones, groans, psychiatric overtones: renal stones from hypercalcemia, hypercalciuria, weakness/constipation = groans. depression/seizures.

45

Tx for nephrogenic DI

HCTZ, indomethacin, amiloride, hydration

46

causes/Tx for SIADH

causes: ectopic ADH, CNS disorders/head trauma, pulm dz, drugs (cyclophosphamide). Tx: fluid restriction, IV hypertonic saline, conivaptan, tolvaptan, demeclocycline

47

histo of DM

T1: islet leukocytic infiltrate. T2: islet amyloid polypeptide (IAPP) deposits

48

glucagonoma

p/w dermatitis (necrolytic migratory erythema), DM, DVT, and depression

49

carcinoid syndrome

1/3 metastasize, 1/3 p/w 2ndary malignancy, 1/3 = multiple. neuroendocrine tumor = most common small intestine malignancy. no Sx if tumor is only in GI b/c of liver metabolism. Sx: recurrent diarrhea, cutaneous flushing, asthmatic wheezing, R-sided valve dz. inc. 5-HIAA in urine, niacin deficiency (pellagra). Tx: resection, somatostatin analog

50

somatostatinoma

-> achlorhydria (gastrin inhibition), cholelithiasis + steatorrhea (CCK inhibition)

51

VIPoma

excessive vasoactive intestinal peptide -> watery diarrhea, hypokalemia, achlorhydria

52

MEN1

AD. 3 Ps: parathyroid tumors, pituitary tumors (prolactin or GH), pancreatic endocrine tumors (SE syndrome, insulinomas, VIPomas, glucagonomas (rare)). associated w/MEN1 gene mutation (menin, = tumor suppressor)

53

MEN2A

AD. 2 Ps: parathyroid hyperplasia, pheochromocytoma. inc. risk of medullary thyroid CA. associated w/marfanoid habitus. RET gene mutation (receptor tyrosine kinase)

54

MEN2B

1P: pheochromocytoma. inc. risk of medullary thyroid CA. oral/intestinal ganglioneuromatosis (mucosal neuromas). associated w/marfanoid habitus. RET mutation.

55

sulfonylureas

1st gen: chlorpropamine, tolbutamide. 2nd gen: glimepiride, pglipizide, glyburide

56

sulfonylurea MoA

close K channel in beta-cell membrane -> cell depolarization -> insulin release via inc. Ca influx: stimulates insulin release.

57

glitazones/thiazolidinediones

inc. insulin sensitivity in peripheral tissue. binds to PPAR-gamma nuclear transcription regulator. side effects: wt. gain, edema, hepatotoxicity, HF, inc. risk of fractures

58

GLP-1 analogs

= exenatide, liraglutide. inc. insulin, dec. glucagon release. side effects: N/V/pancreatitis

59

DPP-4 inhibitors

= linagliptin, saxagliptin, sitagliptin. inc. insulin, dec. glucagon release. side effects: mild UTIs/URIs

60

amylin analogs

= pramlintide. dec. gastric emptying, dec. glucagon. can be used in T1. side effects: hypoglycemia, nausea, diarrhea.

61

SGLT-2 inhibitors

= canagliflozin. block reabsorption of glucose in PCT. side effects: glucosuria, UTIs, yeast infections

62

alpha-glucosidase inhibitors

= acarbose, miglitol. inhibit intestinal brush border alpha-glucosidases. delayed carb hydrolysis and glucose absorption -> dec. postprandial hyperglycemia. side effects: GI upset.

63

PTU/methimizole

block thyroid peroxidase, inhibiting oxidation of iodide and organification (coupling) of iodine -> inhibition of thyroid hormone synthesis. PTU also blocks 5'-deiodinase -> peripheral conversion of T4 -> T3. no methimizole in pregnancy. side effects: skin rash, agranulocytosis, aplastic anemia, hepatotoxicity (PTU). methimizole = possible teratogen

64

ADH-antagonists

conivaptan, tolvaptan. use: SIADH, block ADH at V2 receptor

65

octreotide

= somatostatin analog. Tx: acromegaly, carcinoid syndrome, gastrinoma, glucagonoma, esophageal varices.

66

demeclocycline

MoA: ADH antagonists (in tetracycline family). Tx: SIADH. toxicity: nephrogenic DI, photosensitivity, abnormalities of bone + teeth

67

glucocorticoids MoA

metabolic, catabolic, anti-inflammatory, immunosuppressive effects. inhibits phospholipase A2 and NF-kappaB.

68

cinacalcet

MoA: sensitizes Ca-sensing receptor (CaSR) in parathyroid gland to circulating Ca -> dec. PTH. Tx: hypercalcemia due to primary or secondary hyperPTH. toxicity: hypoCa