The vestigial bony part of the human skeleton is :

IGNOU PB Bsc Entrance-2023

Applied Anatomy

Easy

Appeared in: IGNOU PB Bsc Entrance-2023

Explanation

A vestigial structure is an anatomical feature that has lost most or all of its original ancestral function through evolution.
The coccyx, commonly known as the tailbone, is the terminal part of the vertebral column in humans.
It is considered a vestigial bony part because it is the evolutionary remnant of a tail, a feature that is no longer present or functional in humans.
Anatomical texts describe the coccygeal vertebrae as 'rudimentary', reinforcing their vestigial nature.

Option A: The cranium is the part of the skull that encloses the brain. Its primary function of protecting this vital organ is essential for survival and is not diminished or lost.
Option B: The cervical vertebrae are the seven bones of the neck. They are crucial for supporting the head, allowing for a wide range of motion, and protecting the spinal cord as it exits the skull.
Option D: The clavicle, or collarbone, is a vital component of the shoulder girdle. It connects the arm to the body and acts as a strut to keep the shoulder joint away from the trunk, allowing for maximum arm mobility.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vestigial structures in the human skeleton as background academic context rather than a clinical decision trigger.
A common clinical issue related to the coccyx is coccydynia, which is pain in the tailbone region, often triggered by a fall or prolonged sitting on hard surfaces. Nurses should be aware of this when assessing patients with back or gluteal pain.
Despite being vestigial in its primary role, the coccyx serves as an important attachment site for muscles and ligaments of the pelvic floor. Its integrity is important for pelvic support.
What if? If a patient who recently gave birth complains of persistent lower back and perineal pain, a nurse should consider the possibility of coccygeal trauma during delivery, as the coccyx can be displaced or fractured.

How to Approach the Question

This is a factual recall question that tests your knowledge of human anatomy.
First, identify and define the key term in the question: 'vestigial'. This refers to a body part that has lost its original function through evolution.
Next, evaluate each option based on this definition.
Consider the function of the Cranium (protects brain), Cervical vertebrae (support head), and Clavicle (supports shoulder). These are all essential, active functions.
Consider the function of the Coccyx. It is known as the 'tailbone', which implies it is a remnant of a tail that humans no longer possess.
By comparing the clear, essential functions of the other options with the evolutionary remnant status of the coccyx, you can identify it as the correct answer.

Concept Tested & Keywords

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E6 Anatomy Grays 43e Vol 2 Part 2 p. 20-22

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