Identify the fontanel indicated by the arrow.

Appeared in: AIIMS Jodhpur SNO-2023

Explanation

The image displays a superior view of an infant's skull, with the arrow pointing to the anterior fontanel.
This fontanel is characteristically large and diamond-shaped, which is a key visual identifier.
It is located at the junction of the two frontal bones and the two parietal bones, where the coronal and sagittal sutures meet.
Clinically, it is the last major fontanel to close, typically between 12 and 18 months of age.

Option B: The posterior fontanel is located at the back of the skull, is triangular in shape, and is much smaller than the structure shown.
Option C: The temporal (or sphenoidal) fontanel is located on the side of the skull, in the temple region, not on the top.
Option D: The occipital fontanel is another name for the posterior fontanel. The structure shown is the anterior fontanel due to its diamond shape and anterior location.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomical identification of infant skull fontanels as background academic context rather than a clinical decision trigger.
Assessing fontanels is a fundamental part of the neonatal and infant physical examination. It provides vital clues about hydration status and neurological condition.
A sunken or depressed fontanel in an infant is a classic sign of dehydration and requires prompt fluid replacement.
A tense or bulging fontanel when the infant is calm is a red flag for increased intracranial pressure (ICP), which can be caused by meningitis, hydrocephalus, or intracranial hemorrhage, and constitutes a medical emergency.

How to Approach the Question

First, carefully examine the image provided. Note the view of the skull (superior/top-down) and the specific location the arrow is pointing to.
Identify the key anatomical features of the indicated structure. In this case, observe its large size and distinct diamond shape.
Recall the names and characteristics of the different fontanels in an infant's skull: anterior, posterior, sphenoidal (temporal), and mastoid.
Compare the features seen in the image with your knowledge. The diamond shape and anterior location are characteristic of the anterior fontanel.
Evaluate the given options. 'Anterior fontanel' directly matches your identification. 'Posterior' and 'Occipital' refer to the same triangular fontanel at the back. 'Temporal' refers to the fontanel on the side.
Select the option that correctly identifies the structure based on the visual evidence.

Concept Tested & Keywords

QJSTwt0TKf2d0Azvuwgf9v

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1357-1359

E6 Anatomy Applied Ashalatha 4e p. 274-276

Practise the full AIIMS Jodhpur SNO-2023

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