Skin over the angle of mandible and parotid area is supplied by –
**Core Concept**
The skin over the angle of mandible and parotid area is supplied by branches of the facial nerve (cranial nerve VII) through the great auricular nerve, which is a branch of the cervical plexus (C2-C3 spinal nerves). This area is a unique example of mixed innervation, where the skin receives sensory fibers from the cervical plexus and the underlying parotid gland receives parasympathetic fibers from the facial nerve.
**Why the Correct Answer is Right**
The great auricular nerve, which arises from the cervical plexus, provides sensory innervation to the skin over the angle of mandible and parotid area. This nerve carries postganglionic fibers from the C2 and C3 spinal nerves, which synapse in the cervical plexus. The resulting sensory fibers then travel to the skin, providing sensation to this area. The facial nerve, which also supplies this area, provides motor innervation to the muscles of facial expression and parasympathetic innervation to the salivary glands, including the parotid gland.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not specify the correct nerve or plexus involved in the innervation of the skin over the angle of mandible and parotid area.
**Option B:** This option is incorrect as it refers to a nerve that supplies the auricle and external auditory meatus, not the skin over the angle of mandible and parotid area.
**Option C:** This option is incorrect as it refers to a nerve that supplies the muscles of facial expression, not the skin over the angle of mandible and parotid area.
**Clinical Pearl / High-Yield Fact**
The great auricular nerve is an example of a mixed nerve, which carries both sensory and motor fibers. This mixed innervation is a key feature of this nerve and is essential for understanding the clinical presentation of lesions affecting this nerve.
**Correct Answer: D. The great auricular nerve.**