Hypoglossal Nerve | Structure and Physiology

The video tutorial provides an in-depth look at the hypoglossal nerve, also known as cranial nerve 12. It explains its role as a motor nerve responsible for innervating tongue and some throat muscles. The anatomy of the nerve, including its upper and lower motor neuron components, is discussed, along with its pathway through the hypoglossal canal. The tutorial also covers the implications of lesions on the nerve, detailing how they can cause tongue deviation and how to differentiate between upper and lower motor neuron lesions.

Which cranial nerve is responsible for innervating the tongue muscles?

• Cranial nerve 5

• Cranial nerve 7

• Cranial nerve 10

• Cranial nerve 12

What is the primary function of the hypoglossal nerve?

• Sensory innervation of the face

• Motor innervation of the tongue

• Sensory innervation of the tongue

• Motor innervation of the face

Where does the upper motor neuron of the hypoglossal nerve originate?

• Thalamus

• Cerebellum

• Precentral gyrus

• Medulla oblongata

Through which canal does the hypoglossal nerve exit the cranium?

• Jugular foramen

• Optic canal

• Hypoglossal canal

• Foramen ovale

Which muscles are innervated by the hypoglossal nerve besides the tongue muscles?

• Sternocleidomastoid and trapezius

• Thyrohyoid and geniohyoid

• Masseter and temporalis

• Orbicularis oris and buccinator

What is a sign of a lower motor neuron lesion in the hypoglossal nerve?

• Bilateral tongue deviation

• Ipsilateral tongue deviation

• Contralateral tongue deviation

• No tongue deviation

What happens to the tongue if there is an upper motor neuron lesion in the hypoglossal nerve?

• Ipsilateral deviation

• Bilateral deviation

• Contralateral deviation

• No deviation