Deck VII

Question 1

What characterizes trochlear nerve palsy?

Answer 1

Vertical diplopia.

Question 2

In fragile X syndrome, increased number of trinucleotide repeats leads to gene inactivation of the FMR1 gene via what mechanism?

Answer 2

Hypermethylation of cytosine bases.

Question 3

Thiamine is a cofactor for which enzymes involved in glucose metabolism?

Answer 3

Pyruvate dehydrogenase, a-ketoglutarate dehydrogenase, transketolase.

Question 4

An increase in what product after thiamine infusion is diagnostic for thiamine deficiency?

Answer 4

Erythrocyte transketolase levels.

Question 5

Activity of what product can be measured to diagnose thiamine deficiency?

Answer 5

Erythrocyte transketolase levels.

Question 6

What is a major cause of suicide that access to is considered a major risk factor for completed suicide?

Answer 6

Access to firearms.

Question 7

What symptoms are characteristic of opioid withdrawal?

Answer 7

Abdominal pain, nausea, vomiting, diarrhea, piloerection, lacrimation, diaphoresis.

Question 8

When are MAO-Is indicated for treatment of depression?

Answer 8

Atypical depression.

Question 9

What symptoms characterize atypical depression?

Answer 9

Mood reactivity, leaden fatigue, rejection sensitivity, increased sleep, increased appetite.

Question 10

In the condition ‘nursemaid’s’ elbow, what structures are damaged?

Answer 10

Radial head subluxation, causing weakness/ paralysis of forearm extensor compartment muscles and wrist drop.

Question 11

What is the mechanism of action of ethosuxamide?

Answer 11

Blocks T type Ca2+ channels that trigger/ sustain rhythmic bursts in thalamic neurons; ethosuxamide decreases calcium current in thalamic neurons.

Question 12

In blunt aortic trauma, where is injury to the aorta most common?

Answer 12

Aortic isthmus which is tethered to the ligamentum arterosum (i.e. at top of descending segment)

Question 13

Describe the murmur heard in a patient with aortic regurgitation.

Answer 13

Murmur best heard on the left sternal border when the patient sits up and leans forward at end expiration; early diastolic, high pitched and blowing decrescendo murmur (severe AR can be holodiastolic and present with absence of the A2 heart sound)

Question 14

What vessels serve as the venous drainage of the heart?

Answer 14

Coronary sinus.

Question 15

Which tissue extracts the most oxygen from blood?

Answer 15

The heart

Question 16

In a patient with tetralogy of fallot, squatting during an episode of severe cyanosis and dyspnea (tet spell) helps to:

Answer 16

Increase systemic vascular resistance (increased SVR compared to pul. Vascular resistance permits a greater fraction of total cardiac output to pass through the lungs, thus improving arterial oxygenation.

Question 17

A patient on physical exam with a cardiac murmur, bounding femoral pulses, and carotid pulsations accompanied by head bobbing indicates what condition:

Answer 17

Aortic regurgitation.

Question 18

Name three precipitating factors for isolated episodes of atrial fibrillation.

Answer 18

Binge alcohol consumption, increased cardiac sympathetic tone, pericarditis.

Question 19

What EKG findings are characteristic of a-fib?

Answer 19

Irregularly irregular QRS complexes and absent P waves. P waves are always absent in a-fib because coordinated atrial contractions do not occur.

Question 20

The cardiac action potential is associated with increased and decreased membrane permeability to which ions respectively?

Answer 20

Increased permeability: Na, Ca; Decreased permeability: K

Question 21

A chronic AV shunt causes what types of changes to cardiac output, total peripheral resistance, and venous return?

Answer 21

Increases cardac output (increased sympathetic stimulation); decreased TPR; increased venous return.

Question 22

Elevated activity of which enzyme predisposes a patient with atherosclerotic lesions to plaque rupture and myocardial infarction?

Answer 22

Metalloproteinases (degrade collagen of the plaque’s fibrous cap)

Question 23

Pulmonary Capillary Wedge Pressure (PCWP) most accurately measures what pressure?

Answer 23

Left atrium end diastolic pressure

Question 24

Name two drugs that are selective vasodilators of coronary arteries.

Answer 24

Adenosine, dipyridamole.

Question 25

What is the mechanism of action of adenosine and dipyridamole on coronary arteries?

Answer 25

Vasodilation of coronary arterioles in NON ischemic regions, thus diverting blood flow from ischemic regions. This is called ‘coronary steal’.

Question 26

What is pulsus paradoxus?

Answer 26

A decrease in systolic blood pressure of greater than 10mmHg with inspiration

Question 27

Name four conditions that may cause pulsus paradoxus.

Answer 27

Acute cardiac tamponade, constrictive pericarditis, severe obstructive lung disease, restrictive cardiomyopathy.

Question 28

On auscultation, what is the best indicator of severity of mitral stenosis?

Answer 28

Length of time between S2 (specifically the A2 component caused by aortic valve closure) and the opening snap. Shorter interval indicates more severe stenosis.

Question 29

What compensation mechanism is used to initially attenuate clinically apparent edema in patients with right heart failure?

Answer 29

Increased tissue lymphatic drainage.

Question 30

What characteristic defect is associated with a wide, fixed splitting of S2 that does not vary with respiration?

Answer 30

Atrial septal defect (creates left to right shunt)