Submandibular gland is:
**Core Concept**
The submandibular gland is a major salivary gland that plays a crucial role in the production and secretion of saliva. It is a mixed gland, consisting of both serous and mucous cells, and is located under the mandible (lower jawbone).
**Why the Correct Answer is Right**
The submandibular gland is a major salivary gland that produces a significant portion of the total saliva in the mouth. The gland is divided into two lobes: the larger superficial lobe and the smaller deep lobe. The superficial lobe is located above the mylohyoid muscle, while the deep lobe is located below the muscle. The submandibular gland secretes a mixture of serous and mucous saliva, which helps to facilitate food digestion and swallowing. The gland's secretions are rich in enzymes such as amylase, which breaks down carbohydrates into simple sugars.
**Why Each Wrong Option is Incorrect**
**Option A:** The parotid gland is another major salivary gland, but it is located in the preauricular region, not under the mandible.
**Option B:** The sublingual gland is a minor salivary gland located under the tongue, but it is not as large or prominent as the submandibular gland.
**Option C:** The submandibular gland is not a branch of the facial nerve, although it does receive parasympathetic innervation from the facial nerve via the submandibular ganglion.
**Clinical Pearl / High-Yield Fact**
The submandibular gland is often affected by sialolithiasis, a condition characterized by the formation of stones (sialoliths) in the gland's ducts, which can cause pain and swelling in the region.
**Correct Answer: C. Submandibular gland is a mixed gland, consisting of both serous and mucous cells.**