Physiology Flashcards
Eustachian Tube
Usually closed
opens for swallowing, yawning and sneezing
Opens to equalize pressures
Vestibule
Medial to oval window
Contains organs of balance (utricle and saccule)
Semicircular canals
Help with equilibrium
Detect angular acceleration
Cochlea
Contains organ of corti
Converts mechanical waves into neural impulses to the 8th cranial nerve
Oval window
In vestibule
Conducts sound through tiny fluid filled channels into cochlea
Round window
Communicates with inner ear and permits propagation of fluid waves through perilymph
Which type of hair cells detect high frequency?
Thin, stiff and narrow at base of cochlea
Which type of hair cells respond to low frequencies?
Thick, wide floppy at the apex (tip) of cochlea
The most inner part of the cochlea
Organ of corti
Receptor organ that generates nerve impulses
Movement of basilar membrane causes cilia to sheer back and forth.
They may either depolarize or hyperpolarize.
Ventral cochlear nucleus
Time-sensitive localization pathway
First place nerve impulses from both ears can be compared
Dorsal cochlear nicleus
Analyzes quality of sound to determine minute differences in frequency.
Otolithic Maculae
Detect linear acceleration
Cristae Ampullaris
Semicircular canals
Detect angular acceleration
Unilateral peripheral vestibular dysfxn =
Severe vertigo
Horizontal nystagmus
Bilateral peripheral vestibular dysfxn =
Oscillopsia (blurring w/ head movement)
No vertigo
Imbalance or gait ataxia