The Arrector pili muscle is situated at the:

Appeared in: DSSSB October 2024

Explanation

The arrector pili are microscopic bands of smooth muscle fibers found in the dermis layer of the skin.
These muscles connect the base of a hair follicle to the underlying dermal tissue.
Their location within the skin is fundamental to their function, which is to make hair stand on end (piloerection or 'goosebumps').
This action is an involuntary response controlled by the sympathetic nervous system, often triggered by cold or fear.

Option B: The nose is an organ covered by skin, but the arrector pili muscle is a component of the skin tissue itself, not a structure specific to the nose.
Option C: Similar to the nose, the external ear is covered with skin that contains arrector pili muscles, but 'skin' is the correct and more general anatomical answer for the muscle's location.
Option D: The tongue is a muscular organ covered by a mucous membrane, not skin. It lacks hair follicles and, consequently, does not have arrector pili muscles.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy of the integumentary system, specifically the location of the arrector pili muscle as background academic context rather than a clinical decision trigger.
Piloerection ('goosebumps') is a visible sign of sympathetic nervous system activation, which nurses can observe during patient assessment in response to cold, fear, or other strong emotions.
While largely a vestigial reflex in humans, observing its presence or absence can provide minor clues about a patient's autonomic nervous system function.
What if? If a patient suffers from a third-degree burn, the damage extends through the dermis, destroying hair follicles and the associated arrector pili muscles. In the scarred area, the piloerection reflex would be permanently lost.

How to Approach the Question

Identify the key anatomical structure in the question: 'Arrector pili muscle'.
Recall the function of this muscle. It is responsible for causing 'goosebumps' by making hair stand on end.
Logically connect the function to the location. Since the muscle acts on hair, it must be located where hair follicles are found.
Remember that hair follicles are embedded within the skin.
Evaluate the options. 'Nose' and 'Ear' are body parts covered by skin, making them too specific and less accurate than 'Skin' itself. 'Tongue' does not have hair follicles.
Conclude that 'Skin' is the most accurate and fundamental answer describing the tissue where the arrector pili muscle is situated.

Concept Tested & Keywords

Concept Tested: Anatomy of the integumentary system, specifically the location of the arrector pili muscle.
Stem keywords: Arrector pili muscle, situated at
Lead-in keywords: BEST, MOST RELEVANT CLUE
Negative lead-in flag: false

QIqk1V57wadNqQ7s6o-vM7

E6 Anatomy Applied Ashalatha 4e p. 230-232

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1834-1836

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 4 p. 49-51

Practise the full DSSSB October 2024

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