The umbilical cord is present at term by?

Appeared in: NORCET 1 - 2020

Explanation

The normal umbilical cord at term contains three vessels: two arteries and one vein.
The single umbilical vein carries oxygenated, nutrient-rich blood from the placenta to the fetus.
The two umbilical arteries carry deoxygenated blood and waste products away from the fetus to the placenta.
This configuration results from the embryological process where the right umbilical vein degenerates early in gestation, leaving only the left umbilical vein.
A simple mnemonic to remember this is AVA: Artery-Vein-Artery.

Option A: This describes a two-vessel cord, which is an anomaly, not the normal structure.
Option B: This configuration of one artery and two veins is not a recognized normal or abnormal anatomical structure of the human umbilical cord.
Option D: This four-vessel structure is only present in the very early stages of embryonic development.

Visual 1: Diagram - A cross-section of the umbilical cord. This visual should clearly label the two smaller, thick-walled umbilical arteries and the single larger, thin-walled umbilical vein, all embedded in Wharton's jelly.

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.
It is a standard nursing and obstetric practice to inspect the umbilical cord at birth and count the vessels to ensure it is normal.
The identification of a Single Umbilical Artery (SUA), or a two-vessel cord, is clinically significant as it can be associated with an increased risk of congenital anomalies, particularly of the cardiovascular and genitourinary systems. It prompts a more thorough examination of the newborn.
What if? If a newborn is found to have a single umbilical artery, the standard of care would involve a detailed physical examination and often includes renal ultrasonography and sometimes an echocardiogram to screen for hidden anomalies.

How to Approach the Question

This is a factual recall question testing knowledge of basic fetal anatomy.
Identify the core subject: the structure of the umbilical cord at term.
Recall the normal number of arteries and veins.
A helpful mnemonic is 'AVA' for Artery-Vein-Artery, which helps remember there are two arteries and one vein.
Evaluate each option against this anatomical fact.
Eliminate the options that describe abnormal configurations (one artery, one vein) or transient embryonic structures (two arteries, two veins).

Concept Tested & Keywords

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Practise the full NORCET 1 - 2020

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