HAP- Hearing

Hearing

What structures are involved in hearing? 

The structures of the ear all work together to collect and transfer sound vibrations to the auditory nerve. The ear uses mechanoreceptors to accomplish this. 

What are the three main divisions of the ear? 

Outer ear, middle ear, and inner ear. 

What type of receptors does the ear use?

Mechanoreceptors. 

What is the auricle (pinna)? 

The outer ear that collects sound waves.

What is the path of sound waves through the outer ear?

Sound waves are collected by the auricle (outer ear) and are passed through the external auditory canal. The sound waves then vibrate the tympanic membrane (eardrum). 

What is the tympanic membrane? 

The eardrum. It vibrates when sound waves hit it.

What are the ossicles?

A set of 3 tiny, jointed bones in the middle ear: the malleus, incus, and stapes. They are commonly known as the hammer, anvil, and stirrup.

What is the function of the ossicles? 

They amplify the sound waves and send them to the inner ear through a membrane called the oval window.

What are the common names for the malleus, incus, and stapes? 

Malleus = hammer, incus = anvil, stapes = stirrup. 

What is the cochlea? 

A bony, snail-shaped structure in the inner ear containing membranes filled with fluid called perilymph.

What is the Organ of Corti? 

The tiny portion of the cochlea that creates an impulse.

How is an auditory impulse created? 

Sound from the ossicles vibrates the perilymph. The perilymph then vibrates the basilar membrane, which has tiny receptor cells attached to it. The hairs of the receptor cells move against the tectorial membrane, depolarizing the ends of the nerve cells and beginning an action potential.

What happens after an action potential is created in the ear? 

When the action potential is transferred through the auditory nerve, the brain registers these impulses as sounds.

What is the summary statement for hearing? 

Sound is passed in vibrations through the outer ear and amplified by the tympanic membrane and 3 bones called ossicles. When these vibrations reach the cochlea, perilymph moves the hairs of the receptor cells in the Organ of Corti, causing an impulse to be passed through the auditory nerve to the brain.