U World Questions

Question 1

Blotchy red muscle fibers on Gomori stain are characteristic of

Answer 1

Mitochondrial myopathies
Abnormal mitochondria accumulate under the sarcolemma of muscle fibers –> fibers have an irregular shape and size on cross-section

Question 2

Delayed separation of the umbilical cord;
recurrent cutaneous infections without pus formation;
poor wound healing;
dx?

Answer 2

defect in CD18 - Leukocyte adhesion deficiency

Question 3

HTN classes that reduce mortality in patients with HF

Answer 3

ACE inhibitors
ARBs
Prevent cardiac remodeling

Question 4

Common causes for Candida vaginitis (5)

Answer 4

Antibiotic use
high estrogen levels ie during pregnancy
systemic corticosteroid therapy
uncontrolled DM
immunosuppression ie HIV

Question 5

What vascular beds develop the highest burden of atherosclerosis?

Answer 5

lower abdominal aorta

coronary arteries

Question 6

Excess phenylalanine inhibits:

Answer 6

tyrosinase, required for the downstream production of melanin;
lack of melanin - fair complexion seen in PKU (deficiency of phenylalanine hydroxylase)

Question 7

Intellectual disability by 6 months;
Seizures
Eczema
Light skin/hair

Answer 7

PKU (also musty body odor)
inability to convert phenylalanine to tyrosine
tx with tyrosine in diet, restrict phenylalanine in diet

Question 8

Name the branched chain amino acids:

Answer 8

Leucine
Isoleucine
Valine
elevated in MSUD - deficiency of branched-chain alpha-ketoacid dehydrogenase complex

Question 9

Feeding difficulties
Seizures
Cerebral edema
Sweet odor of urine
Dx?

Answer 9

MSUD

Question 10

The C5-C6 spinal nerves mediate what reflexes?

Answer 10

Biceps and brachioradialis (elbow)

Question 11

C4 Myotome

Answer 11

Shoulder/scapula elevation

Question 12

C5 myotome

Answer 12

Shoulder ABduction

Question 13

C5-C6 myotome

Answer 13

elbow flexion

wrist extension

Question 14

C7 myotome

Answer 14

elbow extension

finger extension

Question 15

C8 myotome

Answer 15

wrist flexion

finger flexion

Question 16

T1 myotome

Answer 16

finger ABduction

Question 17

C7-C8 reflexes

Answer 17

triceps reflex

Question 18

SIADH drug causes:

Answer 18

Carbamazepine
SSRIs
Cyclophosphamide

Question 19

Vasopressin and oxytocin are synthesized within the neurons found in what nuclei?

Answer 19

Paraventricular and supraoptic nuclei;
Neurophysins are involved in the posttranslational processing and stabilization of oxytocin and vasopressin within the neurosecretory vesicles during transport to the posterior pituitary

Question 20

The internal iliac vein (lower rectum) drains to

Answer 20

the caval system

Question 21

The superior rectal vein (upper rectum) drains to

Answer 21

the portal system

Question 22

The venous component of internal hemorrhoids drains into:

Answer 22

the middle and superior rectal veins, which communicate with the internal iliac and inferior mesenteric veins

Question 23

The venous component of external hemorrhoids drains to:

Answer 23

External hemorrhoids drain via the inferior rectal vein into the internal pudendal vein, which communicates with the internal iliac veins

Question 24

Bacterial mRNA can be polycistronic, meaning:

Answer 24

that one mRNA codes for several proteins. Example = lac operon in E. Coli - the transcription and translation of the bacterial proteins is regulated by a single promoter, operator, and set of regulatory proteins;
Eukaryotic mRNA is rarely polycistronic

Question 25

Effect of 2,3 BPG

Answer 25

decreases hemoglobin's affinity for oxygen; | in the presence of lower blood oxygen concentrations, higher 2,3-BPG enable O2 delivery in the peripheral tissues

Question 26

How is 2,3-BPG produced?

Answer 26

Glycolysis pathway Glucose --> Glucose 6P --> Fructose 6P --> Fructose 1,6P --> Glyceraldehyde 3P --> 1,3 BPG Instead of continuing in glycolysis, 1,3 BPG --(mutase in RBCs) --> 2,3 BPG 2,3 BPG can also return to the glycolysis pathway --(phosphatase)--> 3-phosphoglycerate --> 2-phosphoglycerate --> phosphoenolpyruvate --> pyruvate

Question 27

What intermediate step in glycolysis produces ATP?

Answer 27

1,3-BPG --(phosphoglycerate kinase)--> 3-phosphoglycerate

Question 28

Satiety center in the brain

Answer 28

Ventromedial nucleus of the hypothalamus

Question 29

Where do ependymomas arise?

Answer 29

walls of the ventricles can hamper CSF flow and cause hydrocephalus; cells for gland-like structures called "rosettes"

Question 30

Where are medulloblastomas found?

Answer 30

cerebellum, often at the vermis; sheets of small, blue cells; poorly differentiated/poor prognosis

Question 31

Medulloblastomas and what other kind of tumor are found in the cerebellum?

Answer 31

Pilocytic astrocytoma - most common brain tumor in childhood; contain pilocytic astrocytes and rosenthal fibers

Question 32

Indapamide | Class and MOA

Answer 32

Thiazide diuretic Blocks Na/Cl symporters in the distal tubules can cause hypokalemia

Question 33

K+ sparing diuretics (3)

Answer 33

Amiloride Triamterene Spironolactone Block the epithelial sodium channel or aldosterone receptor

Question 34

How can beta-blockers cause hyperkalemia?

Answer 34

Interfere with beta-2-mediated intracellular potassium uptake

Question 35

How can ACE inhibitors cause hyperkalemia?

Answer 35

Inhibition of angiotensin II formation with subsequent decrease in aldosterone secretion

Question 36

How can cardiac glycosides (ie digoxin) cause hyperkalemia?

Answer 36

Inhibition of the Na/K pump

Question 37

How can ARBs cause hyperkalemia?

Answer 37

Block the AT1 receptor, thus decreasing aldosterone secretion

Question 38

How can NSAIDs cause hyperkalemia?

Answer 38

Impaired local prostaglandin synthesis reduces renin and aldosterone secretion

Question 39

MOA Shiga-like toxin

Answer 39

``` Halts protein synthesis by disabling the 60s ribisomal subunit, leading to intestinal epithelial cell death and diarrhea; AB toxin (active A and binding B) encoded by a plasmid transmitted by a bacteriophage ```

Question 40

MOA Tocilizumab

Answer 40

monoclonal antibody to IL-6 | treatment of giant cell arteritis, for which IL-6 is an important marker of disease severity

Question 41

Which Prostaglandins are pro-inflammatory, and cause bronchoconstriction?

Answer 41

TXA2 PGD2 PGF2alpha

Question 42

Which prostaglandins are anti-inflammatory and cause bronchodilation and vasodilation?

Answer 42

PGI2 | PGE2

Question 43

What enzyme catalyzes the formation of arachadonic acid from membrane phospholipids?

Answer 43

Phospholipase A2 (corticosteroids inhibit)

Question 44

Prolonged, untreated obstructive sleep apnea can cause:

Answer 44

pulmonary HTN and RHF

Question 45

Sodium nitroprusside | Use

Answer 45

Management of acute heart failure due to severe hypertension | IV vasodilators

Question 46

Right sided colon cancers are more likely to ______ while left-sided colon cancers are more likely to ______.

Answer 46

Right-sided colon cancers, ie ascending colon, are more likely to: bleed, grow as large bulky masses Left-sided colon cancers are more likely to: infiltrate the wall of the colon, be smaller, cause obstruction

Question 47

What are the protective factors against epithelial ovarian carcinoma?

Answer 47

oral contraceptive use; multiparity, breastfeeding tubal-ligation or salpingo-oophorectomy all reduce the # of times the epithelium of the ovary has to get repaired

Question 48

Warfarin inhibits

Answer 48

epoxide reductase, which converts vitamin K to reduced vitamin K

Question 49

Failure of PT to correct with vitamin K treatment indicates:

Answer 49

liver disease (reflecting factor VII deficiency)

Question 50

Superior sulcus tumors are aka

Answer 50

Pancoast tumors lung apex cause shoulder pain due to compression of the brachial plexus

Question 51

Integrins bind to what ECM components?

Answer 51

Fibronectin Collagen Laminin

Question 52

"HALT" - diseases that involve target cells

Answer 52

HbC disease Asplenia Liver disease Thalassemia

Question 53

Bleeding time is a test of

Answer 53

platelet function

Question 54

Platelets contain (4 main things)

Answer 54

vWF thromboxane A2 fibrinogen COX

Question 55

Autoaintibodies to GpIIb-IIIa | Dx?

Answer 55

Immune thrombocytopenic purpura (ITP)

Question 56

Deficiency of metalloprotease ADAMS-TS13 | Dx?

Answer 56

Thrombotic thrombocytopenic purpura --> microangiopathic hemolytic anemia

Question 57

Hemolysis Uremia Thrombocytopenia Dx?

Answer 57

HUS

Question 58

``` Hemolysis Uremia Thrombocytopenia Neurologic symptoms Fever ```

Answer 58

Thrombotic thrombocytopenic purpura --> microangiopathic hemolytic anemia "Nasty Fever Torched His Kidneys"

Question 59

How is von WIllebrand disease a mixed platelet and coagulation disorder?

Answer 59

vWF is needed to stabilize factor VIII; also binds GpIb to subendothelial collagen Tx: DDAVP (desmopressin) - forces release of vWF from storage cells

Question 60

"STOP Making Thrombi" - causes of DIC

Answer 60

``` Sepsis Trauma OB complications Pancreatitis Malignancy Transfusion ```

Question 61

Clopidogrel Ticlopidine Ticagrelor Prasugrel

Answer 61

ADP receptor inhibitors | ADP binds ADP receptor --> induces GpIIb-IIIa on the surface of platelets

Question 62

Abciximab Tirofiban Eptifibatide

Answer 62

Direct GpIIb-IIIa inhibitors; | use in NON-ST elevation MI

Question 63

Maximum life span of platelet

Answer 63

8-10 days

Question 64

NSAIDs inhibit

Answer 64

Thromboxane A2

Question 65

MOA Enoxaparin

Answer 65

LMWH - inhibits factor Xa