SUBMANDIBULAR GLAND
| A | The submandibular gland is seen to wrap around the posterior border of mylohyoid | |
| B |
The facial artery and vein are divided as they course through the deep part of the gland |
|
| C |
The hypoglossal nerve is seen to loop above the submandibular duct |
|
| D |
Damage to the lingual nerve will cause loss of sensation to the posterior third of the tongue |
Which one of the following is the CORRECT statement during operation on the submandibular gland?
| A |
The submandibular gland is seen to wrap around the posterior border of mylohyoid |
|
| B |
The facial artery and vein are divided as they course through the deep part of the gland |
|
| C |
The hypoglossal nerve is seen to loop above the submandibular duct |
|
| D |
Damage to the lingual nerve will cause loss of sensation to the posterior third of the tongue |
Each submandibular gland is divided into superficial and deep lobes by the posterior edge of the mylohyoid muscle and occupies the submandibular triangle.
- Facial artery courses deep to the submandibular gland, within the submandibular triangle, to exit anterior to the masseter muscle en route to the face.
- The hypoglossal nerve and its venae comitantes are inferior to the submandibular duct.
- The lingual nerve courses into the tongue and carries general sensation from the anterior two-thirds of the tongue.
| A |
Inferior alveolar nerve |
|
| B |
Hypoglossal nerve |
|
| C |
Lingual nerve |
|
| D |
Mandibular branch of facial nerve |
Ans. is ‘a’ i.e., Inferior alveolar nerve
Which of the following nerve does not supply submandibular gland
| A |
Lingual nerve |
|
| B |
Chorda tympani |
|
| C |
Sympathetic plexus |
|
| D |
Auriculotemporal nerve |
Their secretions of submandibular gland, like the secretions of other salivary glands, are regulated directly by the parasympathetic nervous system and indirectly by the sympathetic nervous system.
- Parasympathetic innervation to the submandibular glands is provided by the superior salivatory nucleus via the chorda tympani, a branch of the facial nerve that synapses in the submandibular– ganglion after which it follows the Lingual nerve leaving this nerve as it approaches the gland.
- The sympathetic nervous system regulates submandibular secretions through vasoconstriction of the arteries that supply it. Increased sympathetic activity reduces glandular blood flow, thereby decreasing salivary secretions and producing an enzyme rich mucous saliva.
| A |
Digastric |
|
| B |
Geniohyoid |
|
| C |
Mylohyoid |
|
| D |
Stylohyoid |
Ans. C. Mylohyoid
Submandibular gland
- This walnut sized gland lies below the mandible in the anterior part of digastric triangle. It is .1-shaped and consists of a large superficial and a small deep parts, separated by mylohyoid muscle and continuous with each other around the posterior border of mylohyoid muscle.
Superficial part
- It is situated in the anterior part of digastric triangle. The gland is partially closed in a capsule formed by two layers of deep cervical fascia. It has three surfaces : (i) inferior, (ii) lateral, and (iii) medial.
- Inferior surface is covered by skin, platysma, cervical branch of facial nerve, deep fascia, facial vein and submandibular lymph nodes.
- Lateral surface is related to submandibular fossa (on mandible), medial pterygoid (insertion) and facial artery.
- Medial surface is related to mylohyoid, hyoglossus and styloglossus muscles.
Deep part
- It lies on the hyoglossus muscle deep to mylohoid. It is related above to lingual nerve and submandibular ganglion; and below to hypoglossal nerve.
| A |
Inferior alveolar nerve |
|
| B |
Lingual nerve |
|
| C |
Hypoglossal nerve |
|
| D |
Marginal mandibular branch of facial nerve |
- Submandibular duct runs forward between the lingual nerve and hypoglossal nerve.
- Marginal mandibular branch of facial nerve passes posteroinferior to angle of jaw, so it may be injured if incision is too close to angle of jaw.
- Inferior alveolar nerve enters the mandibular canal through the mandibular foramen and exits as mental nerve at the mental foramen to supply the skin over the chin region.
