MLT GlobeAnatomy: Cardiovascular system – page 2
37 Anatomy MCQs on Cardiovascular system with answers and explanations.
Which feature is found in many veins but not in arteries?
Both vessel types have intima, media and adventitia. Valves, folds of intima, occur in limb veins to prevent backflow.
An artery that is the sole supply to a region, with no effective anastomoses, is termed a(n):
Blocking an end artery (e.g., central retinal artery) causes infarction of its territory because no alternate route exists.
Which vessels are called resistance vessels because they mainly regulate peripheral resistance?
Arterioles have thick smooth muscle relative to lumen and control blood pressure and flow. Large arteries are elastic conduits; veins are capacitance vessels.
Which statement about a normal capillary is correct?
Capillaries are single endothelial tubes about 5–10 µm wide without smooth muscle. Plasma proteins are mostly retained, maintaining oncotic pressure.
The base of the heart, its posterior-superior aspect, is where which structures attach?
The base is formed mainly by the atria where the great vessels enter and leave. The apex points to the left 5th intercostal space.
Where is the sinoatrial (SA) node, the heart's pacemaker, located?
The SA node lies in the right atrial wall near the SVC opening and initiates each heartbeat. The AV node lies near the interatrial septum.
Which of these arteries arises as a single, unpaired branch of the abdominal aorta?
The coeliac trunk, superior and inferior mesenteric arteries are unpaired midline branches. Renal, radial and internal carotid arteries occur on both sides.
Which layer around the heart is fused below to the central tendon of the diaphragm?
The tough fibrous pericardium blends with the central tendon of the diaphragm, anchoring the heart. The serous layers line the pericardial cavity.
Blockage of the "widow-maker" artery involves which branch of the left coronary artery?
The left coronary artery divides into the anterior interventricular (LAD) and circumflex arteries. The posterior interventricular usually comes from the right coronary.
On the right side, the subclavian artery arises from which vessel?
The right subclavian and right common carotid arteries are terminal branches of the brachiocephalic trunk. The left subclavian arises directly from the aortic arch.
Which statement about the axillary artery is correct?
The axillary artery begins at the outer border of the first rib, has three parts, is surrounded by brachial plexus cords and becomes the brachial artery.
Which artery does NOT branch directly from the arch of the aorta?
The aortic arch gives off the brachiocephalic trunk, left common carotid and left subclavian arteries. The right common carotid comes from the brachiocephalic trunk.
What is the main function of the circle of Willis?
The circle joins the internal carotid and vertebrobasilar systems at the base of the brain, so blood can be rerouted if one vessel narrows. It lies on the inferior surface, not the upper surface.
Arteries whose branches connect only at small terminal arterioles, so sudden blockage usually causes infarction, are best exemplified by:
Coronary branches have potential (functionally inadequate) anastomoses, so acute occlusion causes myocardial infarction. The palmar and plantar arches and circle of Willis are actual, effective anastomoses.
The hepatic portal vein is formed by union of the superior mesenteric and splenic veins at which location?
The portal vein forms behind the pancreatic neck at about L1–L2, then ascends behind the first part of the duodenum to the porta hepatis.
The superior sagittal sinus usually drains at the confluence of sinuses into which vessel?
The superior sagittal sinus runs back to the confluence and usually continues as the right transverse sinus. The straight sinus, fed by the inferior sagittal sinus, usually drains to the left.
The fibular (peroneal) artery arises as a branch of which artery?
The fibular artery branches from the posterior tibial artery just below the popliteus and runs along the fibula to supply the lateral leg.