True statement about parotid gland -a) Duct opens opposite to upper 2nd molar toothb) Duct pierces masseterc) Develops from ectodermd) Develops from mesoderme) Secretomotor fibres come from facial nerve

**Core Concept**
The parotid gland is a major salivary gland located near the ear, and its development, anatomy, and innervation are key aspects to understand. The parotid gland is one of the three major salivary glands in the human body, responsible for producing a significant portion of the saliva that helps in digestion.

**Why the Correct Answer is Right**
The parotid gland develops from the ectoderm, specifically from the endoderm of the first pharyngeal pouch. The parotid gland is innervated by the auriculotemporal nerve, which is a branch of the mandibular division of the trigeminal nerve (cranial nerve V3), but the secretomotor fibers come from the facial nerve (cranial nerve VII). The facial nerve provides parasympathetic innervation to the parotid gland, which stimulates saliva production.

**Why Each Wrong Option is Incorrect**
**Option A:** The duct of the parotid gland, known as the Stensen's duct, opens opposite the second upper molar tooth, not the first or third molar tooth. This makes option A incorrect.

**Option B:** The duct of the parotid gland, Stensen's duct, pierces the buccinator muscle, not the masseter muscle. This makes option B incorrect.

**Option C:** The parotid gland develops from the ectoderm, not the mesoderm. This makes option C incorrect.

**Option D:** The parotid gland develops from the ectoderm, not the mesoderm. This makes option D incorrect.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the parotid gland is a mixed gland, meaning it has both serous and mucous secretions. The serous secretions are responsible for the watery portion of saliva, while the mucous secretions help to lubricate food for swallowing.

**Correct Answer:** E. Secretomotor fibres come from facial nerve