VA-BC Vascular Anatomy & Physiology 3 — Questions and Answers
Question 1: Which of the following describes the vasa vasorum?
- Valves within large veins
- Small vessels supplying the walls of large blood vessels (Correct answer)
- Capillary beds in skeletal muscle
- Lymphatic channels alongside arteries
Correct answer: Small vessels supplying the walls of large blood vessels
The vasa vasorum are small blood vessels that supply oxygen and nutrients to the walls of larger blood vessels, particularly in the tunica adventitia and outer media.
Question 2: When a patient's arm is placed in a dependent position, venous pressure in the antecubital fossa increases primarily due to:
- Increased cardiac output
- Hydrostatic pressure from the column of blood (Correct answer)
- Sympathetic vasoconstriction
- Decreased oncotic pressure
Correct answer: Hydrostatic pressure from the column of blood
Placing the arm in a dependent position adds hydrostatic pressure (the weight of the blood column) to venous pressure, making veins more engorged and visible.
Question 3: Which nerve runs in close proximity to the basilic vein in the medial upper arm, making deep basilic vein access potentially risky?
- Radial nerve
- Ulnar nerve
- Median nerve (Correct answer)
- Musculocutaneous nerve
Correct answer: Median nerve
The median nerve runs near the basilic vein in the upper arm, and inadvertent puncture or compression can cause paresthesia or nerve injury.
Question 4: The thoracic duct drains lymph into which vascular structure?
- Right subclavian vein
- Left subclavian vein at the junction with the left internal jugular vein (Correct answer)
- Left axillary vein
- Superior vena cava directly
Correct answer: Left subclavian vein at the junction with the left internal jugular vein
The thoracic duct empties into the venous system at the junction of the left subclavian and left internal jugular veins, returning lymph to circulation.
Question 5: Poiseuille's Law states that blood flow through a vessel is most sensitive to changes in:
- Blood viscosity
- Vessel length
- Vessel radius (Correct answer)
- Driving pressure
Correct answer: Vessel radius
Poiseuille's Law shows flow is proportional to the fourth power of the radius, making small changes in radius have a dramatic effect on flow rate.
Question 6: Which structure separates the subclavian vein from the subclavian artery in the thoracic outlet?
- First rib
- Anterior scalene muscle (Correct answer)
- Middle scalene muscle
- Clavicle
Correct answer: Anterior scalene muscle
The anterior scalene muscle lies between the subclavian vein (anterior) and the subclavian artery (posterior), an important landmark for central venous access.
Question 7: Venous capacitance refers to the ability of veins to:
- Generate high pressure to return blood to the heart
- Store large volumes of blood with minimal pressure change (Correct answer)
- Constrict rapidly in response to hemorrhage
- Deliver oxygen directly to surrounding tissues
Correct answer: Store large volumes of blood with minimal pressure change
Veins are highly compliant (capacitance vessels) and can hold up to 70% of total blood volume with little increase in pressure due to their thin, distensible walls.
VA-BC Vascular Anatomy & Physiology 3
Which of the following describes the vasa vasorum?