The umbilical cord contains \ \ \ \ \ \ \ - RRB Nsg. Superintendent-20 July 2019 (Shift-2)

RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Applied Physiology

Easy

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-2)

Explanation

The umbilical cord is the lifeline between the fetus and the placenta, containing blood vessels that facilitate nutrient and gas exchange.
A normal umbilical cord at term consists of three vessels: two umbilical arteries and one umbilical vein.
The two umbilical arteries carry deoxygenated blood and metabolic waste products away from the fetus to the placenta for disposal.
The single umbilical vein carries oxygenated and nutrient-rich blood from the placenta to the fetus.
A common mnemonic to remember this structure is AVA (Artery-Vein-Artery).

Option A: This option is incorrect. While there are two arteries, there is only one umbilical vein at term. Early in development, two veins are present, but the right one degenerates.
Option B: This option incorrectly states there is one artery and two veins. The correct configuration is the reverse: two arteries and one vein.
Option D: This option describes a two-vessel cord (one artery, one vein), which is an anomaly known as a Single Umbilical Artery (SUA). While it occurs, it is not the normal composition.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy of the umbilical cord as background academic context rather than a clinical decision trigger.
A single umbilical artery (SUA), also known as a two-vessel cord, is the most common congenital anomaly of the cord, occurring in about 1% of singleton pregnancies. It can sometimes be associated with other fetal anomalies, particularly of the cardiac and renal systems.
During newborn assessment, nurses count the vessels in the umbilical cord stump to screen for potential underlying anomalies. The presence of only two vessels warrants documentation and may prompt further evaluation of the newborn.
What if? If a two-vessel cord (one artery, one vein) is identified on a prenatal ultrasound, the standard of care is to perform a detailed fetal anatomy survey to rule out associated congenital anomalies. However, in the absence of other findings, an isolated SUA often has a good prognosis.

How to Approach the Question

This is a factual recall question testing knowledge of basic fetal anatomy.
First, identify the core subject: the composition of the umbilical cord.
Recall the number and types of blood vessels present in a normal umbilical cord.
Remember the mnemonic 'AVA' (Artery-Vein-Artery) to quickly recall that there are two arteries and one vein.
Evaluate the options based on this knowledge. Option A has too many veins. Option B reverses the numbers. Option D describes an abnormal two-vessel cord. Option C correctly identifies two arteries and one vein.
Confirm the selection by remembering the function: arteries carry waste away from the fetus, and the vein brings nutrients to the fetus.

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