Vestibular Function Flashcards
What is the VESTIBULAR SYSTEM?
sensory system essential in control of posture and balance; series of fluid-filled membranous tubes (labyrinths) embedded in temporal bone
What does the vestibular apparatus consist of?
3 semi-circular canals, the utricle to which the canals connect and the saccule
How are the canals oriented?
At right angles to each other
What are ampulla?
Swellings at bases of the canals which contain sensory hair cells
What is the matricle?
Sensory component of utricle and saccule containing sensory hair cells
What are the OTOLITH ORGANS?
The utricle and saccule
Function of the otolith organs?
They detect linear acceleration and encode info about the position of the head in space
What does the utricle specifically detect?
Back/front tilt
What does the saccule specifically detect?
Vertical movement
Function of the semi-circular canals?
Rotational acceleration
What are the swellings at the base of the semi-circular canals called?
the ampulla
What is found inside the ampulla?
sensory receptors called cristae
What do the cristae consist of?
Flexible gelatinous structure called the cupula, which stretches across the width of the ampulla and responds to movement of endolymph fluid within the canals
What is embedded within the gelatinous cupula?
the cilia of hair cells which synapse directly with the sensory neurons of the vestibular nerve (CNVIII)
What do the hair cells of the cupula detect?
Rotational acceleration
