Does the lateral vestibular nucleus projects to abducens nucleus?

Vestibular nerve fibers originating in the left horizontal semicircular canal project to the medial and lateral vestibular nuclei (see Figure 14.10). Excitatory fibers from the medial vestibular nucleus cross to the contralateral abducens nucleus, which has two outputs.

What neuron types are located in the abducens nucleus?

Two primary neuron types are located in the abducens nucleus: motorneurons and interneurons. The former directly drive the contraction of the ipsilateral lateral rectus muscle via the abducens nerve (sixth cranial nerve); contraction of this muscle rotates the eye outward (abduction).

What is the function of vestibular nucleus?

The major vestibular nuclei are highly interconnected with many overlapping functions. It plays an essential role in maintaining equilibrium, posture, head position, and clear vision with movement.

What does abducens nucleus do?

The abducens nucleus is the center for conjugate horizontal movements of the eye. About 70% of the abducens nucleus are motor neurons that control the ipsilateral lateral rectus muscle.

What are the 4 vestibular pathways?

there are 4 important vestibular pathways to consider:

• the primary sensory pathway from the vestibular nuclei (particularly the superior and lateral) to the VP nucleus of the thalamus and then to cortex.
• vestibulospinal reflexes.
• the vestibulo-ocular reflex (VOR)
• vestibulo-cerebellar connections.

How does vestibular information reaches the brain?

The vestibular nerve connects with the cochlear nerve to form the auditory nerve, which relays information to the brain about balance. The vestibulo-ocular reflex ensures stable vision by moving the eyes in the opposite direction of the head.

What is Foville syndrome?

Though several clinical variants have emerged over the years, classical Foville syndrome presents with ipsilateral sixth nerve palsy, facial palsy, and contralateral hemiparesis. Reports exist of other features such as facial hypoesthesia, peripheral deafness, Horner syndrome, ataxia, pain, and thermal hypoesthesia.

How does vestibular nuclei work?

The vestibular nuclei function in conjunction with the cerebellum to maintain equilibrium and posture, convey perception of head position and acceleration, and modify muscle tone. The lateral vestibular nucleus receives input from the semicircular canals and utricle.

What is the nucleus Ambiguus?

The nucleus ambiguus is the common nucleus of the efferent fibers for glossopharyngeal (CN IX) and vagus (CN X) nerves. The nucleus ambiguus provides fibers that innervate the somatic muscles of the pharynx, larynx, and soft palate.

What is the vestibular pathway to the brain?

The vestibular receptors lie in the inner ear next to the auditory cochlea. They detect rotational motion (head turns), linear motion (translations), and tilts of the head relative to gravity and transduce these motions into neural signals that can be sent to the brain.

What part of the brain controls the vestibular system?

Deep inside the ear, positioned just under the brain, is the inner ear. While one part of the inner ear enables hearing, another part, called the vestibular system, is designed to send information about the position of the head to the brain’s movement control centre, the cerebellum.

Where is the abducens nucleus located in the face?

This nucleus is located beneath the fourth ventricle in the caudal portion of the pons, medial to the sulcus limitans . The abducens nucleus along with the internal genu of the facial nerve make up the facial colliculus, a hump at the caudal end of the medial eminence on the dorsal aspect of the pons.

Where are the subnuclei located in the vestibular system?

There are 4 subnuclei; they are situated at the floor of the fourth ventricle . corresponding to the lower part of the area acustica in the rhomboid fossa; the caudal end of this nucleus is sometimes termed the descending or spinal vestibular nucleus .

Where are axons of the vestibular root continued?

Some of the axons of the cells of the lateral nucleus, and possibly also of the medial nucleus, are continued upward through the inferior peduncle to the roof nuclei of the opposite side of the cerebellum, to which also other fibers of the vestibular root are prolonged without interruption in the nuclei of the medulla oblongata.

Is the abducens nerve the same as the internuclear axon?

Lesions of the abducens nerve, the abducens nucleus, or the internuclear axons in the medial longitudinal fasciculus have similar yet individually unique features.