**Question:** Spinal part of accessory nerve supplies -

A. Shoulder joint muscles
B. Cervical sympathetic ganglia
C. Diaphragm
D. Oropharyngeal muscles

**Core Concept:** The accessory nerve is a mixed nerve that originates in the cervical spinal cord and contains both motor and sensory fibers. It has two parts: the cervical spinal part and the cranial part.

**Why the Correct Answer is Right:**
The correct answer, D, refers to the oropharyngeal muscles that the spinal part of the accessory nerve innervates. These muscles include the sternocleidomastoid, trapezius, and omohyoid muscles, which are essential for swallowing, head and neck movements, and maintaining the normal anatomy of the pharynx.

**Why Each Wrong Option is Incorrect:**
A) The cervical sympathetic ganglia belong to the cranial part of the accessory nerve, not the spinal part.
B) The cervical sympathetic ganglia are part of the sympathetic nervous system, not related to the accessory nerve or its spinal part.
C) The diaphragm is innervated by the phrenic nerve, not the spinal part of the accessory nerve.

**Clinical Pearl:** Understanding the anatomy and function of the accessory nerve and its spinal part is crucial for a medical student or doctor, as knowledge of the spinal part's innervation helps to comprehend the pathophysiology of conditions like Horner's syndrome, which involves damage to the accessory nerve or its spinal part. This knowledge is essential for accurate diagnosis and appropriate treatment of such conditions.