Lecture 17 - The Vestibular System Flashcards
What kind of information does the vestibular system
- Which way is up
- Where you are going
How many receptor organs are in the Vestibular Labyrinth?
Five
What are linear acceleration detected by?
- Utricle
- Saccule
What are angular acceleration measured by?
Semicircular canals
What do certain cells in the epithelium produce?
Endolymph
What is the role for endolymph
Extracellular fluid that bathes the apical surface
- Is rich in K+ but poor in Na+ & Ca2+
What is the structure of Hair cells in the vestibular system?
- Five clusters of hair cells
- Stereocilia at the apical ends
- Kinocilium at one end of the stereoscilia
What is the role the tip link that connects to steroeocilia?
- Connects to an ion channel
- Causes it to open
What do the hair cells act as?
Mechanoelectrical transducers
What happens when the hair bindle deflects towards the kinocilium?
- Causes depolarisation
- Enhances transmitter release
What happens whrn the hair bundle deflects away from the kinocilium?
- Causes hyperpolarisation
- Reduces transmitter release
Where do the hair cells of the vestibular system recieve inputs from?
The brain stem
What is the otolithic membrane?
A sheet that covers the entire macula
The otolithic membrane […] the movement of the head.
Lags behind
What does horizontal acceleration do to the utricle?
- One group of hair cells will activate
- Oppositely oriented hair cells will be suppressed
