March 30 Flashcards Preview

1 USMLE-rx > March 30 > Flashcards

Flashcards in March 30 Deck (33):
1

Pheochromocytomas arise from _____ cells of the adrenal medulla, which are derived from _____ cells?

Chromaffin
Neural crest

2

Why are PDE-5 inhibitors CI when pt is on nitrates?

PDE-5 inhibitor prevent degradation of cGMP and can cause severe hypotension

PDE-5 normally inhibits cGMP which prevents NO-induced vasodilation
--but blocks its action--increase cGMP =vasodilation which is only increased with nitrates

3

What type of anemia can result from GI bleeding, such as with colon cancer?

Iron-deficiency anemia--microcytic anemia

4

Thalassemia major can be differentiated from iron-deficiency anemia by what, because they both result in microcytic anemia?

Normal iron level with thalassemia major

5

What are the 2 most common manifestations of AD von hippel-Lindau disease?

Hemangioblastomas and renal cell carcinoma

6

Pt with mid-shaft humerus fracture are suspected to have damage to what nerve and loss of what?

Radial nerve-C5-T1
Loss of extension of the wrist--wrist drop

7

What is the cause of the mutation to the CFTR gene on CH. 7 seen with CF?

Causes abnormal protein folding of the CFTR Cl- channel

8

What are the 4 muscles of mastication and which one(s) lower the jaw and which one(s) close the jaw?

Lower--Lateral pterygoid --- Lateral Lowers

Close--Masseter, teMporalis, Medial pterygoid--- M's Munch

9

What are polymyxins used for and what are their side effects?

Used for gram (-) bugs--bind to and destroy cell membrane

Toxicities:
-Numbness of extremities
-Confusion
-Drowsiness
-Nystagmus
-Blurred vision

10

What nerve can become compressed in athletes leading to decreased medial thigh sensation and decreased adduction?

Obturator--L2-L4

11

HbS during sickle cell crisis causes what type of shift in O2 dissociation curve?

Right shift--lower affinity for O2

12

Immunodeficiency that presents with coarse facies, recurrent staph abscesses, eczema and elevated IgE?

Job syndrome--Autosomal dominant hyper-IgE syndrome

Increase IgE and Decreased IFN-g--which leads to less phagocytic activity of macrophages b/c IFN-g is released from Th1 cells and activates macrophages

13

This enzyme is found in all tissues, phosphorylates glucose for conversion into storage glycogen and is inhibited by glucose-6-phosphate?

Hexokinase

14

What muscle is the origin of cremaster muscle?

Internal oblique

15

Where is Broca's area located?

Inferior frontal gyrus

16

Immunodeficiency that presents after 6 months of age, in boys, with lack of B-cell maturation and increased incidence of bacterial infections?

X-linked (Bruton) agammaglobulinemia

Markedly decreased IgG and IgM and low IgA

Absent/scanty lymph nodes and tonsils

17

What runs through the Cardinal ligament?

Uterine artery and vein

18

Niacin (Vit B3) deficiency results in what?

Pellagra
-Diarrhea
-Dementia
-Dermatitis--C3/C4 dermatome circumferential "broad collar" rash
-Hyperpigmentation of sun-exposed limbs

Glossitis can occur with mild deficiency

19

What branchial arches are responsible for generation of muscles that allow for palate elevation?

Branchial arches 3 and 4

3--stylopharyngeus---CN IX--swallow with style
4--Most pharyngeal constrictors; cricothyroid, levator veli palatini--CN X simply swallow

20

What congenital infection is associated with a PDA?

Rubella

21

What is deficient with maple syrup urine disease?

a-ketoacid dehydrogenase

22

What is decreased in hemochromatosis?

Decreased total iron-binding capacity (TIBC) which is an indirect measure of serum transferrin, a protein that binds iron in the blood stream --so you would have an increased saturation of transferrin

23

What neoplasm is associated with Auer rods?

Acute myelogenous leukemia

24

What neoplasm is associated with Down syndrome and t(15;17) translocation and what is the tx for this cancer?

Acute promyelocytic leukemia--responds to all-trans retinoid acid (Vit A)--which causes differentiation of promyelocytes

Commonly presents with DIC and Auer rod inclusions

25

What personality disorder is characterized by unstable mood, impulsivity, suicidality and sense of emptiness?

Borderline personality disorder --Cluster B

26

What is the prodrug of prednisolone and is converted by 11-B-hydroxysteroid dehydrogenase?

Prednisone

27

What is responsible for formation of male external genitalia?

DHT--Dihydrotestosterone

Also responsible for secondary sex characteristics and causes increased size of epididymis and prostate.

5a-reductase converts testosterone to DHT

28

What occurs across the RBC membrane when CO2 levels are elevated in the blood?

Cl- is exchanged for HCO3- so more Cl- enters the cell to compensate for the increased carbonic anhydrase activity

29

What 2 cells utilize the SGLT which acquire glucose through co-transport with Na?

Enterocytes and nephron cells

30

When determining primers for PCR what do you use?

Top 5' start--left
Bottom 5' start--right
------->
5' ATAGTACCG------------GACTAGCAC 3'
3' TATCATGGC-------------CTGATCGTG 5'

31

What type of HSR is serum sickness?

Type III HSR ---immune complexes are formed and deposited in membranes where they fix complement

32

What is seen in the CSF of pt with Guillain-Barre syndrome?

Elevated protein
Normal cell count

33

C. diff produces virulence factors that cause what cellular event to occur in the intestinal epithelial cells?

Apoptosis

Toxin-A binds to the brush border and Toxin- B which causes depolymerization of actin cytoskeleton