Smallest artery is?

Appeared in: BSF Staff Nurse - 2021

Explanation

Arterioles are the terminal branches of the arterial system, acting as the final link before the capillary beds.
They are defined by their small diameter (approximately 30 micrometers) and a relatively thick muscular wall.
This muscular structure allows them to constrict and dilate, making them the primary sites of peripheral vascular resistance and key regulators of blood pressure.

Option B: Venules are part of the venous system, not the arterial system. They are the smallest veins that collect blood from capillaries.
Option C: A vein is a general term for a large vessel that carries blood toward the heart. It is significantly larger than an arteriole.
Option D: An artery is a broad category of blood vessels that carry blood away from the heart. Arterioles are a specific type of artery.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and physiology of the vascular system, specifically the hierarchy of blood vessels as background academic context rather than a clinical decision trigger.
The muscular tone of arterioles is the primary determinant of Total Peripheral Resistance (TPR), a critical component of blood pressure regulation (Blood Pressure = Cardiac Output × TPR).
Many antihypertensive medications, such as calcium channel blockers and ACE inhibitors, work by causing vasodilation (relaxation) of arterioles, which lowers peripheral resistance and, consequently, blood pressure.
What if? If the question asked for the smallest blood vessel overall, the answer would be capillaries. Capillaries (5-10 μm) are smaller than arterioles but are primarily sites of nutrient and gas exchange, not resistance control.

How to Approach the Question

First, identify the key terms in the question: 'smallest' and 'artery'.
Recall the hierarchical structure of the circulatory system, specifically the path blood takes away from the heart.
The sequence is: Aorta → Large Arteries → Small Arteries → Arterioles → Capillaries.
Eliminate options that belong to the venous system (vessels returning blood to the heart), which are 'Venules' and 'Vein'.
Compare the remaining options, 'Artery' and 'Arterioles'. 'Artery' is a general category, whereas 'Arterioles' are specifically the smallest vessels within that category.
Select 'Arterioles' as the most precise and correct answer.

Concept Tested & Keywords

Concept Tested: Anatomy and physiology of the vascular system, specifically the hierarchy of blood vessels.
Stem keywords: Smallest artery
Lead-in keywords: is
Negative lead-in flag: false

Qu_P7zlo7Qo6hQhWH3lIvi

E6 Physiology Ganong 27e Vol 2 Part 1 p. 117-119

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 3 p. 51-53

Practise the full BSF Staff Nurse - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.