Question

What are the contents of umbilical cord?

• A. 2 arteries, 2 veins
• B. 1 artery, 2 veins
• C. 2 arteries, 1 vein
• D. 1 artery, 1 vein

Hint:

Umbilical cord has two arteries and one vein. Remember: AAV = Artery, Artery, Vein.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the normal vascular contents of a mature human umbilical cord at term.
This is a high-yield topic in both embryology and obstetrics.
Step 2: Detailed Explanation:

Early Fetal Development: Initially, during the early stages of embryogenesis, there are two umbilical arteries and two umbilical veins (right and left).

Natural Regression: As development proceeds, the right umbilical vein normally undergoes total regression and disappears around the end of the second month (8 weeks).

Components at Term: By the time of birth, the normal umbilical cord contains exactly three vessels: two umbilical arteries and one (the left) umbilical vein.

Functional Roles of the Vessels:

Umbilical Vein (1): It carries oxygenated, nutrient-rich blood from the placenta to the fetus. This is the only vessel in the cord carrying high oxygen content.

Umbilical Arteries (2): They carry deoxygenated blood and metabolic waste products from the fetus back to the placenta for excretion and re-oxygenation.

Surrounding Structures: These vessels are embedded in a specialized mucoid connective tissue called Wharton’s jelly, which prevents vessel compression and kinking.

Clinical Significance: A "Single Umbilical Artery" (two-vessel cord) is an anomaly found in about 1% of pregnancies and can be associated with fetal renal or cardiac defects.


Step 3: Final Answer:
A mature umbilical cord normally consists of two umbilical arteries and one umbilical vein.