Usmle - What I Learned 2

Front 1

Pathophys of Fedriech's Ataxia

Back 1

-AR condition due to expanding trinucleotide repeat on Chr 9
-Degeneration of spinocerebellar tract and dorsal root ganglion
-Results in:
(1) Progressive ataxia in 5-15 y/o pts
(2) Hypertrophic cardiomyopathy --> arrythmias and CHF (most common cause of death)
(3) Skeletal abnormalities kyphoscoliosis, pes cavus, and hammertoes
(4) Diabetes mellitus

Front 2

Which artery is most likely to get damaged in a femoral neck fracture

Back 2

Medial circumflex

Front 3

Order of enzymes involved in base excision repair

Back 3

Glycoslyase
Endonuclease
Lyase
Polymerase
Ligase

Front 4

How does strep viridans bind to heart valves?

Back 4

Binds to fibrin-platelet aggregates. Therefore it must adhere to damaged sites on heart valves

Front 5

Characterize the structure of tRNA:

(1) length
(2) acceptor stem
(3) 3' tail
(4) D arm
(5) Anticodon arm
(6) T arm

Back 5

(1) 74-90 nts
(2) base pairing between 3' and 5' ends w/ CCA seq hanging off 3' end
(3) CCA tail is where amino acid binds
(4) Has dihydrouracil residues
(5) Binds mRNA
(6) Has T-psi-C sequence necessary for binding ribosomes

Front 6

Mucosal IgA is produced by which type of vaccines: Killed or Live-attenuated

Back 6

Live attenuated!
Mucosal IgA provides more effective immunity. Live attenuated vaccines colonize mucosal cells resulting in IgA production

Front 7

Blood gases after aclimating to high altitudes

Back 7

Hypoxemia + respiratory alkalosis (due to inc respiratory rate) + decrease bicarb (due to renal comp)

Front 8

Opiod analgesics effect on GI

Back 8

Contraction of smooth muscle --> constipation and closure of sphincters (rarely results in biliary colic due to contraction of Sphincter of Oddi)

Front 9

Two diseases caused by C. perferingens

Back 9

(1) Gas gangerene
(2) LATE-onset watery diarrhea from food poisoning (cells must colonize GI and product toxin before diarrhea occurs)

Front 10

Anatomy related to
(1) Indirect inguinal hernias
(2) Direct inguinal hernias
(3) Femoral hernias

Back 10

(1) Indirect inguinal --> male infant. enters inguinal ring LATERAL to inferior epigastric vessels. Caused by PERSISTENT PROCESSUS VAGINALIS & FAILURE of INTERNAL RING to close

(2) Direct inguinal hernia --> older males. Bulges through hasselbech's triangle (MEDIAL to epigrastric vessels). Due to weakness of TRANSVERSUS FASCIA

(3) Femoral hernai --> Women. protrudes through femoral ring, MEDIAL to femoral vessels and inferior to inguinal ligaments

Front 11

Child squats to recover from cyanosis, indicates what

Back 11

Squatting makes a R->L shunt into L->R shunt thus reducing hypoxemia

Front 12

Heart sounds heard best in left lateral decubitus position

Back 12

S3, S4 and mitral stenosis

Front 13

S3 arises from

Back 13

Can be physiological in young people, but path in older. Due to blood rushing into a partially filled ventricle or a very stiff ventricle

Expiration and left lateral decubitus increase S3 sound by bringing heart closer to the chest wall

Front 14

ABDCE of melanoma

Back 14

Asymmetry
Border irregularities
Color variations
Diameter > 6mm
Evolving size, shape or color

Often mets to the brain

Front 15

Concentric hypertrophy results from volume overload or pressure overload?

Back 15

Pressure overload

Front 16

Pathophys of ankylosing spondylitis

Back 16

(1) Inflammation of tendon insertion sites results:
(a) Pain at joints
(b) Decreased chest expansion during respiration

(2) Aortitis --> aortic insufficiency
(3) Uveitis

Front 17

Decreased chest wall compliance would do what to PO2 and PCO2

Back 17

Decrease PO2 and increase PCO2

Front 18

What signal controls the amount of Fe release from enterocytes into circulation and which cells produce that signal

Back 18

(1) Hepcidin
(2) Hepatic parenchyma produce hepcidin

Front 19

Causes of pancytopenia due to aplastic crisis

Back 19

Radiation
Benzene / arsenic exposure
Chloramphenicol
Infection

Front 20

Stimulus for eNOS (produces NO) by endothelial cells

Back 20

Ach
Bradykinin
Shear stress

Front 21

Amino acid precursors of
(1) NO
(2) Urea

Back 21

(1) Arg + O2 --> NO + citrulline
(2) Arg + Asp --> Urea

Front 22

Amino acid precursors of
(1) Heme
(2) Creatine

Back 22

(1) Gly + Succinyl-CoA --> heme
(2) Gly + Arg + SAM --> Creatine

Front 23

AA precursors of
(1) GABA
(2) Glutathione
(3) Pyrimidines
(4) Purines

Back 23

(1) Glu --> GABA
(2) Glu --> Glutathione
(3) Glu + Asp --> Pyrimidine
(4) Glu + Arg + Gly --> Purine

Front 24

AA precursors of
(1) Histamine
(2) DOPA

Back 24

(1) Histidine --> Histamine
(2) Phe --> Tyr --> DOPA

Front 25

AA precursors of
(1) Serotonin
(2) T3/T4
(3) Niacin

Back 25

(1) Tyr --> Serotonin
(2) Tyr --> T3/T4
(3) Trp --> Niacin