Ears

What is the function of the pinna (auricle)?

Collects sound

What is the external auditory canal also called?

External auditory meatus

Where does the external auditory canal end?

At the tympanic membrane (eardrum)

What do the cilia lining the external auditory canal do?

Aid in transmitting sound waves inward

What is the function of ceruminous glands?

Produce antibacterial earwax

What is the tympanic cavity filled with?

Air

What is the function of the auditory ossicles?

Transfer and amplify sound from the eardrum to the inner ear

Which auditory ossicle is connected to the tympanic membrane?

Malleus

What does the incus do?

Transmits sound vibrations from the malleus to the stapes

What is the role of the stapes?

Transmits sound vibrations from the incus to the inner ear

What does the Eustachian tube connect?

Middle ear to the pharynx

What is the function of the Eustachian tube?

Equalizes pressure during yawning or swallowing

What does the oval window separate?

Middle ear from the inner ear

What fits into the oval window?

Base of the stapes

What is the vestibule?

The central portion of the inner ear

Where is the vestibule located?

Between the cochlea and semicircular canals, next to the stapes

What structures in the vestibule help maintain static equilibrium?

Utricle and saccule

What do the semicircular canals contain?

Cristae

What is the function of the semicircular canals?

Maintain balance and motion (dynamic equilibrium)

How many semicircular canals are there?

Three

What fluids are found in the cochlea?

Endolymph and perilymph

What is the function of cochlear fluids?

Transmit sound vibrations

What structure in the cochlea contains receptors for hearing?

Organ of Corti

What are the receptors in the Organ of Corti?

Hair cells on the basilar membrane

What membrane bends the hair cells in the Organ of Corti?

Tectorial membrane

What fluid pushes the tectorial membrane?

Endolymph

What does the Organ of Corti convert sound vibrations into?

Nerve impulses

Which nerve transmits impulses from the Organ of Corti to the brain?

Cochlear nerve

Where are auditory signals interpreted in the brain?

Auditory cortex in the temporal lobe

What causes the tectorial membrane to move?

Vibrations from sound waves

What fluid do sound vibrations pass through in the cochlear duct?

Endolymph

What happens when hair cells are bent by the tectorial membrane?

An action potential starts in the cochlear nerve

Where is the sound signal first transmitted for auditory reflexes?

Midbrain

Where is the sound signal ultimately

Auditory cortex of the temporal lobe

What can continued stimulation of hair cells lead to?

Adaptation

What structures in the vestibule sense linear acceleration and gravity?

Maculae with otolith

Which plane does the utricle primarily sense movement in?

Horizontal

Which plane does the saccule primarily sense movement in?

Vertical

What do the cristae in the semicircular canals detect?

Angular acceleration

Which semicircular canal plane is activated when you nod "yes"?

Sagittal plane

Which semicircular canal plane is involved when shaking your head "no"?

Horizontal plane

Where is static equilibrium detected?

Vestibule (utricle and saccule)

Where is dynamic equilibrium detected?

Semicircular canals (ampulla)

Through which nerve is equilibrium information sent to the brain?

Vestibular nerve

Which part of the brain processes equilibrium information?

Cerebellum

Which plane senses angular acceleration when tilting the head left or right on the shoulder?

Coronal plane

Where are the receptors for static equilibrium located?

Maculae in the vestibule

What is the function of otoliths in static equilibrium?

They shift with linear movements to bend hair cells and initiate action potentials

What initiates the action potential in static equilibrium?

Bending of hair cells due to the shift in otoliths

How does moving in an elevator affect static equilibrium?

It causes leg muscles to adjust tone as the body adjusts position

Where are the receptors for dynamic equilibrium located?

Crista ampullaris in the semicircular canals

What covers the hair cells in the crista ampullaris?

Cupula (gelatinous cap)

What causes the movement of the cupula in dynamic equilibrium?

Angular head movements and acceleration that move the endolymph

What is the result of the cupula touching hair cells during angular movements?

It initiates an impulse sent to the cerebellum via the vestibular nerve

How does dynamic equilibrium help during activities like dancing or aerobics?

It adjusts muscle tone and eye movement to maintain orientation during active movements