The plexus that supplies nerves to the skin and muscles of the upper limbs and some of the chest muscles is?

AIIMS Raipur NO - 2017 (Shift-1)

Applied Anatomy

Easy

Appeared in: AIIMS Raipur NO - 2017 (Shift-1)

Explanation

The brachial plexus is a network of nerves formed by the ventral rami of the C5, C6, C7, C8, and T1 spinal nerves.
It provides the entire motor and sensory nerve supply to the upper limb, including the shoulder, arm, forearm, and hand.
As shown in the provided diagram, its branches include major nerves like the median, ulnar, and radial nerves.
It also innervates some chest muscles, such as the pectoralis major and minor.

Option A: The cervical plexus (C1-C4) primarily supplies nerves to the skin and muscles of the head, neck, and the superior part of the shoulders and chest. Its most significant motor branch is the phrenic nerve, which innervates the diaphragm.
Option C: The lumbar plexus (L1-L4) supplies the anterolateral abdominal wall, external genitalia, and parts of the lower limb, specifically the anterior and medial thigh.
Option D: The sacral plexus (L4-S4) supplies the buttocks, perineum, and the posterior aspect of the thigh and most of the leg and foot. It gives rise to the sciatic nerve, the largest nerve in the body.

Visual 1: Diagram of the Brachial Plexus: To visualize the complex network of roots, trunks, divisions, cords, and branches that supply the upper limb.
Visual 2: Infographic comparing the four major spinal plexuses: To show the distinct anatomical locations and areas of innervation for the cervical, brachial, lumbar, and sacral plexuses.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and function of spinal nerve plexuses as background academic context rather than a clinical decision trigger.
Understanding the brachial plexus is crucial for nurses when assessing patients with upper limb trauma, weakness, or sensory loss.
Injury to the brachial plexus can have devastating consequences on a person's ability to perform activities of daily living. Nurses play a key role in the rehabilitation and support of these patients.
What if? If a patient presented with paralysis of the diaphragm (inability to breathe properly) but had normal arm function, the injury would most likely be to the phrenic nerve, originating from the cervical plexus (C3-C5), not the brachial plexus.

How to Approach the Question

First, analyze the question stem to identify the key anatomical region: "upper limbs and some of the chest muscles".
Next, examine the provided image. Identify the structures shown. The image is a clear diagram of the brachial plexus, showing its roots (C5-T1) and branches extending towards the arm.
Correlate the function described in the question with the anatomical structure in the image. The function (supplying the upper limb) matches the structure (brachial plexus).
Evaluate the options provided. 'Brachial plexus' is one of the options.
Recall the functions of the other plexuses. Cervical (neck/diaphragm), Lumbar (anterior lower limb), and Sacral (posterior lower limb) do not supply the upper limbs.
Select 'Brachial plexus' as it is the only option that matches both the described function and the provided visual aid.

Concept Tested & Keywords

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