Equilibrium and Hearing

These flashcards encompass key concepts related to equilibrium and hearing, covering the anatomy and functions of the ear, sound detection processes, and the neural pathways involved in auditory processing.

What are the three regions of the ear involved in balance and hearing?

External Ear, Middle Ear, Internal Ear.

What is the function of the auricle?

It is the fleshy outer structure of the external ear.

What do ceruminous glands produce?

Waxy, antimicrobial cerumen (earwax).

What is the tympanic membrane?

The eardrum that separates the external ear from the middle ear.

What are the auditory ossicles?

Malleus, Incus, and Stapes that transmit sound.

What is the function of the auditory tube (Eustachian tube)?

It connects the tympanic cavity to the nasopharynx and equalizes air pressure.

What type of waves travel as sound waves through air?

Pressure waves.

What does frequency measure in sound waves?

The number of waves per second, measured in Hertz.

What frequency generates a lower pitch?

Lower frequency.

What is amplitude in sound waves?

The size of the waves which influences volume.

What does lower amplitude signify?

Waves with less energy and lower volume.

What connects the malleus and stapes?

The incus.

What covers the oval window?

The stapes.

What muscles protect the eardrum and ossicles from loud noises?

Tensor Tympani and Stapedius.

What is the bony labyrinth?

It contains structures involved in equilibrium and hearing.

What fluid is contained within the membranous labyrinth?

Endolymph.

What separates the bony labyrinth from the membranous labyrinth?

Perilymph.

What are the three types of semicircular canals?

Anterior, Posterior, and Lateral.

What is the ampulla?

The beginning of each semicircular duct that contains hair cells.

What types of processes do hair cells have?

Kinocilium and Stereocilia.

What are otoliths?

Calcium carbonate crystals that cover the maculae.

What does the cochlea contain?

Hair cells (receptors) used for hearing.

What structure lies on the basilar membrane?

The spiral organ (of Corti).

What does the basilar membrane's stiffness and width affect?

How it distorts in response to different frequency sounds.

What is the vestibular complex responsible for?

Equilibrium sensations.

How does endolymph flow affect hair cells?

It opens or closes mechanically-gated K+ channels in stereocilia.

What does vertical and horizontal movement detection in the utricle and saccule depend on?

Movement of the processes of the maculae.

What do sensory neurons in the vestibular ganglia form?

The vestibular nerve.

Where do CN VIII synapses occur?

Within the vestibular nuclei in the brainstem.

What is the first step in sound detection by the ear?

Sound waves enter the external acoustic meatus.

What does the tympanic membrane do when sound waves hit it?

Vibrates and transmits the vibration to the auditory ossicles.

What structure sends pressure waves through perilymph?

Oval window.

What causes movement of the hair cells against the tectorial membrane?

Distortion of the basilar membrane.

Where do impulses from hair cells travel to the brain?

Via the cochlear nerve (a branch of CN VIII).

What is a characteristic pathway for auditory processing in the brain?

Cochlear branch of CN VIII → Cochlear nuclei → Inferior colliculi → Thalamus → Auditory cortex.