EDAIC Cardiovascular Physiology and Pharmacology 5

Question 1

Which of the following best describes Poiseuille's law as applied to vascular resistance?

Accepted Answer

Resistance is inversely proportional to the fourth power of radius

Answer

Poiseuille's law states resistance = 8ηL/πr⁴, meaning resistance is inversely proportional to the fourth power of radius—a small change in radius causes a large change in resistance.

Question 2

In a patient receiving norepinephrine infusion, which hemodynamic change is expected?

Accepted Answer

Increased SVR, reflex bradycardia, variable CO

Answer

Norepinephrine predominantly activates alpha-1 receptors, increasing SVR and MAP; reflex vagal bradycardia may occur, and CO may decrease, stay unchanged, or increase depending on baseline status.

Question 3

The plateau of the oxygen-hemoglobin dissociation curve has clinical significance because it means:

Accepted Answer

SaO2 remains high over a wide range of PaO2 values above 60 mmHg

Answer

The flat upper portion of the oxyhemoglobin dissociation curve means SaO2 remains above 90% across a wide PaO2 range (60-100 mmHg), providing a safety margin.

Question 4

Adenosine terminates paroxysmal supraventricular tachycardia by:

Accepted Answer

Transiently blocking AV nodal conduction via A1 receptor activation

Answer

Adenosine activates A1 receptors in the AV node, activating GIRK channels and hyperpolarizing the node, causing transient AV block that interrupts re-entrant circuits.

Question 5

Which statement about the Windkessel effect of the aorta is correct?

Accepted Answer

Aortic compliance buffers systolic pressure and maintains diastolic flow

Answer

The Windkessel effect describes how aortic compliance stores energy during systole and releases it in diastole, maintaining forward flow and reducing pulse pressure.

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC - European Diploma in Anesthesiology and Intensive Care Practice Test

EDAIC Cardiovascular Physiology and Pharmacology 5