27/04/2025
The salivary glands are innervated by both the autonomic and somatic nervous systems. Here’s a detailed overview of the nerves that innervate the major salivary glands:
# # # Major Salivary Glands
1. **Parotid Gland**
- **Nerve Supply:**
- **Parasympathetic Innervation:** The glossopharyngeal nerve (cranial nerve IX) provides parasympathetic fibers that originate in the otic ganglion. Preganglionic fibers travel with the lesser petrosal nerve, synapting in the otic ganglion, and postganglionic fibers then travel to innervate the parotid gland.
- **Sympathetic Innervation:** The sympathetic fibers arise from the superior cervical ganglion and travel to the gland via the external carotid artery.
2. **Submandibular Gland**
- **Nerve Supply:**
- **Parasympathetic Innervation:** The facial nerve (cranial nerve VII) gives rise to the chorda tympani, which then joins the lingual nerve. The preganglionic fibers synapse in the submandibular ganglion, and postganglionic fibers innervate the submandibular gland.
- **Sympathetic Innervation:** Like the parotid gland, sympathetic fibers come from the superior cervical ganglion and follow the external carotid artery.
3. **Sublingual Gland**
- **Nerve Supply:**
- **Parasympathetic Innervation:** The same pathway as the submandibular gland (facial nerve via the chorda tympani).
- **Sympathetic Innervation:** Also similar to submandibular, with fibers originating from the superior cervical ganglion.
# # # Minor Salivary Glands
The minor salivary glands, located throughout the oral cavity, are also innervated by autonomic nerves:
- **Parasympathetic Innervation:** Primarily from the facial nerve (via the branches of the lingual nerve, glossopharyngeal, or directly).
- **Sympathetic Innervation:** From the cervical sympathetic ganglia.
# # # Function
- **Parasympathetic Stimulation:** Increases saliva production, stimulating secretion of watery saliva that contains enzymes.
- **Sympathetic Stimulation:** May decrease saliva production, resulting in thicker saliva and reduced secretion.
# # # Summary
Understanding the nerve supply of the salivary glands is crucial for understanding their physiological function, the production of saliva, and the impact of various medical conditions or treatments on salivary secretion.
