An umbilical cord contains?

Appeared in: Uttarakhand CHO - 2021

Explanation

A full-term umbilical cord is composed of two umbilical arteries and one umbilical vein.
The umbilical arteries are responsible for carrying deoxygenated blood and waste products away from the fetus to the placenta.
The single umbilical vein carries oxygenated and nutrient-rich blood from the placenta to the fetus.
This arrangement can be easily remembered with the mnemonic 'AVA' (Artery-Vein-Artery).
As seen in the image, the two arteries are smaller with thicker walls, while the single vein is larger with a thinner wall.

Option A: This describes a single umbilical artery (SUA), which is an anatomical variation, not the normal structure. It is associated with an increased risk of congenital anomalies.
Option B: In early embryonic development, there are two umbilical veins. However, the right umbilical vein typically regresses, leaving only the single left umbilical vein at term.
Option C: This is not the correct anatomical structure for a human umbilical cord. It represents an incorrect count of both arteries and veins.

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 crucial nursing responsibility in the delivery room is to inspect the cut end of the umbilical cord to confirm the presence of three vessels (two arteries and one vein).
The absence of one umbilical artery, a condition known as Single Umbilical Artery (SUA), must be documented and reported as it can be associated with cardiac, renal, and gastrointestinal defects, as well as chromosomal abnormalities.
What if? If a nurse identifies only two vessels (one artery, one vein), the standard of care requires notifying the pediatrician or neonatal team for further assessment of the newborn for potential congenital anomalies.

How to Approach the Question

This is a factual recall question testing knowledge of basic fetal anatomy.
First, identify the key subject of the question: the composition of the umbilical cord.
Recall the standard anatomical structure of the umbilical cord in a term fetus.
Use the mnemonic 'AVA' (Artery-Vein-Artery) to remember that there are two arteries and one vein.
Visually confirm this structure if an image is provided, noting the different appearances of the arteries (smaller, thicker walls) and the vein (larger, thinner wall).
Evaluate the options and select the one that matches the 'two arteries and one vein' structure.

Concept Tested & Keywords

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E6 Histology Inderbir 11e p. 5-7

E6 Obstetrics Williams p. 71-95

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 778-780

Practise the full Uttarakhand CHO - 2021

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