Anatomy LE 6: Auditory and Vestibular Pathways

What happens to sound waves when they enter the external ear?

They strike the tympanic membrane, causing vibration

What is the function of the ossicles in the middle ear?

To transmit vibrations to the cochlea

What happens to the vibrations of the stapes in the oval window?

They are vibrated with increased strength and decreased amplitude

What is the function of the perilymph in the scala vestibuli?

To create pressure waves that displace the basilar membrane Signup and view all the answers

How do the frequencies of sound waves affect the basilar membrane?

Short waves displace the membrane near the oval window, while longer waves displace it nearer to the helicotrema Signup and view all the answers

What is the role of the hair cells in the spiral organ?

To bend and release neurotransmitters, stimulating action potentials Signup and view all the answers

What happens to the pressure waves in the perilymph of the scala tympani?

They are dissipated by the secondary tympanic membrane Signup and view all the answers

What is the primary function of the vestibular nuclei?

Control of balance and eye movements Signup and view all the answers

Where do primary vestibulocerebellar fibers project to?

Flocculonodular lobe and uvula Signup and view all the answers

What is the characteristic of secondary vestibulocerebellar fibers?

They arise from vestibular nuclei Signup and view all the answers

What is the composition of the inferior cerebellar peduncle?

Restiform body and juxtarestiform body Signup and view all the answers

Which part of the inferior cerebellar peduncle is purely afferent?

Restiform body Signup and view all the answers

What is the function of the juxtarestiform body?

Both afferent and efferent Signup and view all the answers

Where do secondary vestibulocerebellar fibers cross over?

At the vermis of the cerebellum Signup and view all the answers

Which acoustic stria arises from the dorsal cochlear nucleus?

Dorsal Acoustic Stria Signup and view all the answers

Which nuclei receive projections from the ventral acoustic stria?

Trapezoid body and superior olivary nuclei Signup and view all the answers

Where do the projections from the inferior colliculus terminate?

Medial geniculate body Signup and view all the answers

What is the final sensory relay station in the auditory pathway?

Medial geniculate body Signup and view all the answers

Where do the auditory radiations terminate?

Primary auditory cortex Signup and view all the answers

What is the location of the primary auditory cortex?

Heschl's gyrus/ anterior transverse temporal gyrus/ BA 41 Signup and view all the answers

At which point do the acoustic striae cross to the other side?

Dorsal pontine tegmentum Signup and view all the answers

What is the direction of the slow component in nystagmus?

Opposite the irrigated ear Signup and view all the answers

In a unilateral vestibular lesion, which side will the eyes, head, and body turn towards?

The affected side Signup and view all the answers

What is vertigo?

The illusion or sensation of whirling Signup and view all the answers

What characterizes nystagmus?

A slow movement of the eyes in one direction followed by rapid return to the opposite side Signup and view all the answers

What is the result of a unilateral vestibular lesion?

Unsteadiness and postural deviation to the affected side Signup and view all the answers

What is the direction of the fast component in nystagmus?

Away from the irrigated ear Signup and view all the answers

What is the difference between vertigo and dizziness?

Vertigo refers to the illusion or sensation of whirling, while dizziness is a feeling of lightheadedness Signup and view all the answers

What is responsible for detecting angular motion?

Cristae ampullares Signup and view all the answers

What is the sensation felt when you are in a vehicle moving back and forth?

Horizontal movement Signup and view all the answers

What happens when the right horizontal duct is stimulated?

The left horizontal duct is inhibited Signup and view all the answers

What is the location of the cristae ampullaris?

Ampulla Signup and view all the answers

What is the sensation felt when you are in an elevator moving up and down?

Vertical movement Signup and view all the answers

What is the effect of stimulating the right anterior duct?

The left posterior duct is inhibited Signup and view all the answers

What structure senses vertical movement?

Macula sacculi Signup and view all the answers

What is the function of the cristae ampullares in the ampulla?

Detecting angular motion Signup and view all the answers

What happens to the left horizontal duct when the right horizontal duct is stimulated?

It is inhibited Signup and view all the answers

What is the location of the macula utriculi?