Blood vessel which connects artery and vein?

WCL Staff Nurse - 2019

Applied Anatomy

Easy

Appeared in: WCL Staff Nurse - 2019

Explanation

Capillaries are microscopic blood vessels that form an intricate network connecting arterioles (the smallest arteries) to venules (the smallest veins).
The provided diagram clearly illustrates this relationship, showing the capillary bed situated between the arteriole and the venule.
Their walls are extremely thin—only a single endothelial cell layer thick—which is the key structural feature that facilitates their primary function.
This function is the exchange of gases (oxygen and carbon dioxide), nutrients, and metabolic waste products between the blood and the surrounding body tissues.

Option A: Venules are small veins that collect deoxygenated blood from the capillaries; they do not connect directly to arteries.
Option B: Arterioles are small arteries that deliver oxygenated blood to the capillaries; they do not connect directly to veins.
Option D: In the vascular system, a sinus is a wide venous channel or cavity, such as the dural venous sinuses in the brain. It is not the primary connecting vessel in the microcirculation.

Clinical Relevance

Nursing practice connection: Knowing Microcirculation and vascular anatomy helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Assessing capillary function is a key nursing skill. For example, checking the Capillary Refill Time (CRT) by pressing on a patient's nail bed helps evaluate peripheral perfusion and hydration status.
A normal CRT is typically 2 seconds or less. A prolonged CRT (greater than 2 seconds) can indicate serious issues like dehydration, shock, or peripheral vascular disease, requiring further assessment and intervention.
What if? If a patient has severe peripheral edema, the increased interstitial fluid can compress capillaries, impairing blood flow and nutrient exchange. This increases the risk of skin breakdown and poor wound healing, making meticulous skin care a nursing priority.

How to Approach the Question

First, analyze the question to identify the core concept: it asks for the specific blood vessel that connects an artery and a vein.
Next, carefully examine the provided image. The diagram explicitly labels 'Artery,' 'Arteriole,' 'Capillaries,' 'Venule,' and 'Vein' in sequence, with arrows showing the direction of blood flow.
Observe that the 'Capillaries' are shown as a network linking the 'Arteriole' (which comes from the artery) and the 'Venule' (which leads to the vein). This visually answers the question.
Finally, compare this observation with the given options. The term 'Capillary' is listed as an option.
Select this as the correct answer based on the direct visual evidence from the diagram and your knowledge of circulatory anatomy.

Concept Tested & Keywords

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

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