Which muscle is supplied by 12th cranial nerve?
The hypoglossal nerve is the twelfth cranial nerve, and innervates all the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus which is innervated by the vagus nerve. It is a nerve with a solely motor function.
What does the 12th cranial nerve control?
XII. Your hypoglossal nerve is the 12th cranial nerve which is responsible for the movement of most of the muscles in your tongue. It starts in the medulla oblongata and moves down into the jaw, where it reaches the tongue.
What is nerve XII?
The hypoglossal nerve is one of 12 cranial nerves. It’s also known as the 12th cranial nerve, cranial nerve 12 or CNXII. This nerve starts at the base of your brain. It travels down your neck and branches out, ending at the base and underside of your tongue.
What happens when the hypoglossal nerve is damaged?
The hypoglossal nerve can be damaged at the hypoglossal nucleus (nuclear), above the hypoglossal nucleus (supranuclear), or interrupted at the motor axons (infranuclear). Such damage causes paralysis, fasciculations (as noted by a scalloped appearance of the tongue), and eventual atrophy of the tongue muscles.
How do you assess cranial nerve 12?
The 12th (hypoglossal) cranial nerve is evaluated by asking the patient to extend the tongue and inspecting it for atrophy, fasciculations, and weakness (deviation is toward the side of a lesion).
What are the 12 cranial nerves and their uses?
Overview of the 12 CNs
| CN | Function | Quality |
|---|---|---|
| I—olfactory nerve (smell) | Transmits signals from the olfactory organ (nose) to the brain | Somatosensory and afferent |
| II—optic nerve (vision) | Transmits visual signals from the retina to the brain | Somatosensory and afferent |
Which is a function of the hypoglossal XII nerve?
The hypoglossal nerve (CN XII) is exclusively a motor nerve carrying general somatic efferent fibers (GSE). It innervates all intrinsic and almost all extrinsic muscles of the tongue, as well as one suprahyoid muscle, the geniohyoid muscle.
What is 12th cranial nerve palsy?
Disorders of the 12th cranial nerve (hypoglossal nerve) cause weakness or wasting (atrophy) of the tongue on the affected side. This nerve moves the tongue. Hypoglossal nerve disorders may be caused by tumors, strokes, infections, injuries, or amyotrophic lateral sclerosis.
¿Cómo se clasifican los pares craneales?
¿Cómo se clasifican y distribuyen los pares craneales? Los pares craneales se llaman así porque se cuentan a pares, al existir uno tanto en el lado derecho como en el izquierdo del cerebro. Así, hay doce nervios craneales apuntando hacia el hemisferio derecho y otros doce apuntando hacia el izquierdo, de manera simétrica.
¿Qué ocurre con las lesiones intracraneales?
Las lesiones intracraneales ocurren durante el curso intracraneal del nervio facial (próximo al agujero estilomastoideo). Los músculos de la expresión facial se paralizarán o se debilitarán gravemente.
¿Cuál es la causa de la lesión intracraneal del nervio facial?
La causa más común de una lesión intracraneal del nervio facial es la patología del oído medio, como un tumor o una infección. Si no se puede encontrar una causa definitiva, la enfermedad se denomina parálisis de Bell.
¿Cuáles son los pares craneales del encéfalo?
Partiendo desde áreas que están por encima del tronco del encéfalo están los pares I y II. Partiendo del mesencéfalo (la parte superior del tronco encefálico), están los pares craneales III y IV. Partiendo del puente de Varolio (o puente troncoencefálico), están los nervios craneales V, VI, VII y VIII.