Usmle Step 1 Flashcards - Endocrinology

Front 1

Where are the Islets of Langerhans most numerous?

Back 1

Tail of the pancreas

Front 2

Effect of insulin on the kidney?

Back 2

Increase Na+ reabsorption

Front 3

Cells that DON'T need insulin for glucose uptake?

Back 3

Brain
RBC
Intestine
Cornea
Kidney
Liver

Front 4

Cells that use GLUT1 transporter?

Back 4

Brain and RBCs

Front 5

Cells that use GLUT2 transporter?

Back 5

Beta islet cells
Liver
Kidney
Small intestine

Front 6

Embryological origin of anterior and posterior pituitary?

Back 6

Anterior: oral ectoderm (Rathke's pouch)

Posterior: neuroectoderm

Front 7

Where do neurophysins work?

Back 7

They carry proteins of hormones from the hypothalamus to posterior pituitary.

Front 8

Embryological origin of adrenal cortex and medulla?

Back 8

Adrenal cortex: mesoderm

Adrenal medulla: neural crest

Front 9

The same alpha subunit is shared by which hormones?

Back 9

TSH
LH
FSH
hCG

Front 10

Somatostatin mainly inhibits what 2 hormones from the pituitary?

Back 10

GH and TSH

Front 11

Cause of apparent mineralocorticoid excess?

Back 11

Deficiency or inhibition of 11-beta-HSD2 (normally degrades cortisol to cortisone)
--> cortisol is able to bind to MR and act like aldosterone

Front 12

2 compounds that osteoblasts produce?

Back 12

M-CSF and RANK-L

Production of both is increased by PTH.

Front 13

Cause and effect of low Mg on the endocrine system?

Back 13

Causes: diarrhea, AGs, diuretics, alcohol

Effect: low Mg decreases PTH secretion

Front 14

Effect of PTH on osteoblasts and osteoclasts?

Back 14

Directly stimulates osteoblasts (which indirectly stimulates osteoclasts).

Also directly stimulates osteoclasts.

--> Enhances bone matrix degradation

Front 15

Causes of low phosphate?

Back 15

Low Vitamin D
Insulin (phosphorylated glucose)
Primary hyper-PTH
PTHrP
Metabolic/resp alkalosis (activate PFK)
Vitamin D-resistant rickets

Front 16

What increases in the urine with PTH stimulation?

Back 16

Urine (PO4)3-

Urinary cAMP

Front 17

Breakdown of total body Ca?

Back 17

40% bound to albumin
Some bound to phosphate
13% bound to citrate
47% free/ionized

Front 18

Effect of high and low levels of SHBG in men vs women?

Back 18

Men: high levels --> lower free testosterone --> gynecomastia

Women: low levels --> higher free testosterone --> hirsutism

Front 19

Testosterone in blood?

Back 19

1-2% free
30-50% bound to albumin
40-50% bound to SHBG

Front 20

Where is most T3 formed?

Back 20

In the blood

Front 21

3 causes of decreased TBG levels?

Back 21

Hepatic failure
Anabolic steroid use
Nephrotic syndrome

Front 22

Hormone with nuclear receptors?

Back 22

T3/T4

Front 23

Hormones that use receptor-associated tyrosine kinase (JAK/STAT pathway)?

Back 23

GH and prolactin

Front 24

Hormones that use intrinsic tyrosine kinase (MAP kinase pathway)?

Back 24

Insulin, IGF-1, FGF, PDGF

^^ Growth factors

Front 25

Hormones that work through IP3 pathway?

Back 25

GnRH, Oxytocin, ADH (V1), TRH

"GOAT"

Front 26

Hormones that work through cGMP pathway?

Back 26

ANP, NO (EDRF)

Front 27

Hormones that work through cAMP pathway?

Back 27

FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2), MSH, PTH
+ calcitonin, GHRH, glucagon

"FLAT CHAMP" + CGG

Front 28

Risks for Waterhouse-Friderichsen syndrome?

Back 28

Neisseria meningitidis septicemia
DIC (or anti-coagulation)
Endotoxic shock (or hypotension)

Front 29

Primary vs secondary Addison's disease?

Back 29

Primary: due to adrenal atrophy or destruction by disease (aldosterone AND cortisol deficiency)

Secondary: decreased ACTH production (low cortisol, normal aldosterone)

Front 30

Polyglandular autoimmune syndrome (PAS) type I?

Back 30

Addison's
Primary hypo-PTH
Mucocutaneous candidiasis

Autosomal recessive, in kids

Front 31

Polyglandular autoimmune syndrome (PAS) type II?

Back 31

Addison's
Hashimoto's
Type I DM

Autosomal dominant, in adults, associated with HLA DR3/4.

Front 32

What condition is opsoclonus-myoclonus syndrome is associated with?

Back 32

Neuroblastoma

Affects 2-3% of pts

Front 33

Pheochromocytomas are associated with what other conditions?

Back 33

Neurofibromatosis
MEN IIa
MEN IIb

Front 34

Symptoms (5 P's) of pheochromocytoma?

Back 34

Perspiration
Pain (headache)
Palpitations
Pressure (HTN)
Pallor

Front 35

Breakdown of NE by MAO produces what? COMT?

Back 35

NE
--> MAO --> VMA
--> COMT --> normetanephrine

Front 36

Secondary causes of hyperaldosteronism?

Back 36

Renal artery stenosis
Chronic renal failure
CHF
Cirrhosis
Nephrotic syndrome

Front 37

Change in lab values with hyperthyroidism?

Back 37

Increased glu, Ca, lymphocytes

Decreased cholesterol

Front 38

Bone pain with cystic bone spaces filled with brown fibrous tissue?

Back 38

Osteitis fibrosa cystica

Front 39

What is Chvostek's sign?

Back 39

Tapping of facial nerve causes contraction of facial muscles

Front 40

Occlusion of brachial artery with BP cuff causes carpal spasm. Sign?

Back 40

Trousseau's sign

Sign of hypocalcemia

Front 41

Cause and findings in pseudohypo-PTH (Albright's hereditary osteodystrophy)?

Back 41

Cause: autosomal dominant kidney unresponsiveness to PTH

Findings: hypocalcemia, short 4th/5th digits, short stature

Front 42

Histology of thyroid gland in Hashimoto's?

Back 42

Hurthle cells with lymphocytic infiltrate with germinal centers

Front 43

Endemic vs sporadic cretinism?

Back 43

Endemic: iodide deficiency

Sporadic: defect in T4 formation or thyroid developemental failure

Front 44

Findings in cretinism (5 P's)?

Back 44

Pot-bellied
Pale
Puffy-faced
Protruding umbilicus
Protuberant tongue

Front 45

Subacute painful vs painless thyroiditis?

Back 45

Painful: de Quervain's (follows flu-like illness)

Painless: lymphocytic, autoimmune/post-partum

Front 46

Findings in de Quervain's thyroiditis?

Back 46

Elevated ESR
Jaw pain
Early inflammation
Very tender thyroid

Front 47

Jod-Basedow phenomenon?

Back 47

Thyrotoxicosis if a patient with iodine deficiency goiter is made iodine replete

Front 48

Medullary thyroid cancer histology?

Back 48

Sheets of cells in amyloid stroma

Front 49

4 findings in diabetic retinopathy?

Back 49

Hemorrhage
Exudates
Microaneurysms
Vessel proliferation (VEGF)

Front 50

Histology of type 1 vs type 2 DM?

Back 50

Type 1: islet leukocytic infiltrate (insulitis)

Type 2: islet amyloid deposit

Front 51

Aldosterone level in SIADH?

Back 51

LOW (body tries to maintain near-normal volume)

Front 52

Causes of central DI?

Back 52

Pituitary tumor
Trauma
Surgery
Histiocytosis X

Front 53

Treatments for nephrogenic DI?

Back 53

Hydrochlorothiazide
Indomethacin
Amiloride

Front 54

Common presentation of MEN I?

Back 54

Kidney stones and stomach ulcers

Front 55

Inheritance of MEN syndromes?

Back 55

All are autosomal dominant

Front 56

Where is tumor located in Zollinger-Ellison syndrome?

Back 56

Pancreas or duodenum

Front 57

Rule of 1/3s for carcinoid syndrome?

Back 57

1/3 metastasize
1/3 present with 2nd malignancy
1/3 multiple

Front 58

Complications of DKA?

Back 58

Life threatening mucormycosis/Rhizopus
Cerebral edema
Cardiac arrhythmias
Heart failure

Front 59

Drug to control uterine hemorrhage?

Back 59

Oxytocin

Front 60

Specific toxicities of Propylthiouracil vs Methimazole?

Back 60

PTU: hepatotoxic

Methimazole: teratogenic

Both can cause skin rash, agranulocytosis, and aplastic anemia.

Front 61

Rapid, intermediate, and long acting insulins?

Back 61

Rapid: Lispro, Aspart, and Regular

Intermediate: NPH

Long: Glargine, Detemir

Front 62

Which diabetic drug can cause pancreatitis?

Back 62

Exenatide (GLP-1 analog)

Front 63

Action of Pramlintide (amylin mimetic)?

Back 63

Decrease glucagon release

Front 64

Mechanism of Acarbose and Miglitol?

Back 64

Alpha-glucosidase inhibitors

(inhibit intestinal brush border enzymes that hydrolyze sugars --> decreased glucose absorption)

Front 65

Diabetic agents that bind PPAR-gamma?

Back 65

Glitazones/thiazolidinediones:
- Pioglitazone
- Rosiglitazone

Front 66

1st vs 2nd generation sulfonylureas?

Back 66

1st gen: Tolbutamide, Chlorpropamide

2nd gen: Glyburide, Glimepiride, Glipizide

Front 67

AE of 1st vs 2nd generation sulfonylureas?

Back 67

1st gen: disulfiram-like effects

2nd gen: hypoglycemia

Front 68

17-OH-progesterone levels in each congenital adrenal hyperplasia?

Back 68

Increased in: 21-hydroxylase and 11-beta-hydroxylase deficiency

Decreased in: 17-alpha-hydroxylase deficiency

Front 69

11-deoxycorticosterone (DOC) is a precursor to what and is elevated in what condition?

Back 69

Precursor to aldosterone. It has mineralocorticoid activity.

Elevated in 11-beta-hydroxylase deficiency.

Front 70

17-hydroxy-corticoids refer to what?

Back 70

11-deoxycortisol (precursor to cortisol) and cortisol