After birth of a healthy neonate, the ductus arteriosus becomes the?

Appeared in: UPUMS Nsg.Officer-2024

Explanation

The ductus arteriosus is a fetal blood vessel that connects the pulmonary artery to the descending aorta, shunting blood away from the non-functional lungs.
After birth, increased oxygen tension in the blood causes the smooth muscle in the wall of the ductus arteriosus to constrict.
This functional closure is followed by anatomical closure, where the vessel fibroses and becomes the ligamentum arteriosum, a solid cord of tissue.

Option A: The venous ligament (ligamentum venosum) is the remnant of the ductus venosus, not the ductus arteriosus.
Option B: The vesical ligaments (medial umbilical ligaments) are the remnants of the umbilical arteries.
Option D: The ligamentum teres is the remnant of the umbilical vein.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Postnatal changes in fetal circulatory structures as background academic context rather than a clinical decision trigger.
Knowledge of fetal-to-neonatal circulatory changes is fundamental for nurses to identify congenital heart defects.
Failure of the ductus arteriosus to close after birth results in a condition called Patent Ductus Arteriosus (PDA). This allows oxygen-rich blood from the aorta to mix with oxygen-poor blood in the pulmonary artery, potentially leading to pulmonary hypertension and heart failure.
Nurses monitor for signs of PDA, such as a continuous machine-like murmur, bounding pulses, and signs of respiratory distress, especially in premature infants.

How to Approach the Question

Identify the key term in the question: 'ductus arteriosus'.
The question asks for the postnatal remnant of this fetal structure.
Recall the major fetal circulatory structures and their adult counterparts. A useful mnemonic is that the names often correspond (e.g., 'arteriosus' becomes 'arteriosum').
Evaluate each option based on your knowledge of fetal circulation:
Venous ligament comes from the ductus venosus.
Vesical ligament comes from the umbilical arteries.

Concept Tested & Keywords

QRj76YDbPHgfMZFQQ1d1cs

E6 Anatomy Grays 43e Vol 1 Part 2 pp. 59-61, 60-62

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 523-525

Practise the full UPUMS Nsg.Officer-2024

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