Vestibular System Flashcards
The vestibular system informs the brain about ______________, _______ ___________, and _________ _________________.
motion, head position, and spatial orientation
Why is vestibular information important?
It is critical for regulating motor function, stabilizing gaze, head and posture.
What are the 2 otolith organs?
1.) utricle
2.) saccule
What detect linear accelerations of the head and static head position relative to the gravitational axis?
utricle and saccule (otolith organs)
What detect rotational accelerations of the head?
semicircular canals
otolith organs= ___________ accelerations
linear
semicircular canals= _______________ acceleration
rotational
The utricle is located _________________ and detects ________________ orientation.
horizontally ; horizontal
The saccule is oriented ___________________ and detects _______________orientation.
vertically; vertical
Both otolith organs make up the ___________.
macula
What are arrays of vestibular hair cells called?
macula
Hair cells are covered by the________________________ ________________ , a gelatinous matrix with ___________ on top.
otolithic membrane
crystals
What are the three sections of the semicircular canal?
1.) Superior
2.) Posterior
3.) Horizontal
Order of layers of the hair cell:
TOP
* calcium crystals
* gelatinous matrix (otolithic membrane)
* supporting cells
* nerve fiber
BOTTOM
What is the expansion of the canals that contain the cristae?
ampulla
What is an epithelium containing sensory hair cells called?
cristae
On top of the hair cells there’s a gelatinous mass where the tips of the hair cells reside, called the ____________ .
cupula
The semicircular canals are filled with ____________ (like the cochlea).
endolymph
What is the largest CN sensory nucleus in the midbrain?
vestibular nucleus
How many subdivisions is the vestibular nucleus divided into? Where are these mostly located?
4
medulla
What are the subdivisions of the vestibular nucleus called?
- lateral vestibular nucleus
- superior vestibular nucleus
- medial vestibular nucleus
- inferior vestibular nucleus
Bipolar cells from the vestibular ganglia stemming from the ________, _______________, and ________________________ innervate different regions of the brainstem.
utricle, the saccule, and the semicircular canals
What are the parts of the vestibular cortex?
- Frontal eye fields
- 2v, 3a
- Posterior Parietal cortex 7, VIP, MIP, MST
- The parieto-insular-vestibular area (PIVC)
Neurons from the vestibular nuclei extend efferents to:
BONUS: what are the reasons or impacts of those pathways?
- The spinal cord: equilibratory reflexes (posture)
- Trochlear (CN IV), abducens (CN VI), and oculomotor nuclei (CN III): vestibulo‐ocular reflex
- The cerebellum: balance and posture
- The thalamus and vestibular cortex
What is the function of the frontal eye fields cortex?
Control eye movements and receive vestibular motion information
What is the function of the 2v and 3a cortex?
Somatosensory areas that map body location and movement signals.
What is the function of the Posterior Parietal cortex 7, VIP, MIP, MST cortex?
Involved with motion perception and responds to both visual and vestibular motion cues.
What is the function of the PIVC?
Responds to body and head motion information
What is the pathway of the vestibular system?
otolith -> gel matrix -> hair cells -> electrical signals -> vestibular nerves
What is the diagnosis of someone having excess Ca rocks/crystals?
vertigo (will have stronger and more signals expressed)
