Hypoglossal nerve Flashcards
1
Q
nuclei of Hypoglossal nerve
A
hypoglossal nucleus
2
Q
location and function of the hypoglossal nucleus
A
- medulla, elongated coloumn of multipoal cells extending in both open and closed parts in the floor of the rhomboid fossa
- somatomotor
3
Q
brain exit of Hypoglossal nerve
A
medial paraolivary sulcus
4
Q
dura penetration of Hypoglossal nerve
A
hypoglossal canal
5
Q
skull exit of Hypoglossal nerve
A
hypoglossal canal
6
Q
pathway of Hypoglossal nerve
A
- nerve spirals behind the vagus nerve
- passes between internal carotid a. & internal jugular vein lying on the carotid sheath
- passes deep to the post. belly of the digastric muscle
- ascending in an arch forming the loop hypoglossal nerve
- nerve reaches the root of tongue slightly above hyoid bone in the lateral lingual sulcus
- before reaching the tongue, some fiber bundles from the 1st and 2nd cervical spinal nerves will adhere to the nerve giving fibers that will innervate some of the supra/infrahyoidal muscles, in the lateral lingual sulcus it ramifies into branches:
7
Q
branches from the hypoglossal supplying:
A
- intrinsic muscles of tongue
- extrinsic muscles of tongue
- supra/infrahyyoidal muscles
8
Q
intrinsic muscles of tongue
A
- sup. longitudinal muscle
- inferior longitudinal muscle
- verticalis muscle
- transversus muscle
9
Q
extrinsic muscle of tongue
A
- genioglossus muscle
- hyoglossus muscle
- styloglossus muscle
10
Q
supra/infrahyoidal muscles (via the c1/c2 cervical segments received from the deep cervical ansa)
A
- geniohyoid muscle
- thyrohyoid
11
Q
where do the other fibers go?
A
other fibers from c1/c2 will continue as the superior root of cervical ansa and will meet the inferior root of the ansa made the ventral rami of c2/c3 forming the deep cervical ansa that will innervate
- omohyoid
- sternothyroid
- sternohyoid
