Topic 10 - Ears Flashcards
3 parts of vestibular labyrinth
- Semicircular canals
- Otolith organs
- Vestibular nerve
Roll
Side to side bending
Pitch
Nodding head “yes” movement
Yaw
Shaking head “no” movement
What do semicircular canals respond to
Angular acceleration
What do the otolith organs respond to
Linear acceleration of the head and static orientation
Utricle - horizontal linear
Saccule - vertical linear
2 parts of otolith organs
Utricle
Saccule
Ascending tract for vestibular system
Vestibulothalamic pathway
Going to thalamus
Descending tracts for vestibular system
Lateral vestibulospinal tract
Medial vestibulospinal tract
Vestibulotectal tract
Lateral vestibulospinal tract
Vestibular labyrinth - vestibular nuclei - lateral vestibular nuclei - lumbosacral region
Stabilizes muscles in lower limbs
- excites extensors, inhibits flexors
Reflex control of posture
Medial vestibulospinal tract
Vestibular labyrinth - vestibular nuclei - medial vestibular nuclei - cervical region
Stabilizes muscles in neck
Reflex control of head
Vestibulotectal tract
Vestibular labyrinth - vestibular nuclei - superior vestibular nuclei - superior colliculus
Involved in stabilizing visual gaze while your head is moving
(Vestibuloocular reflex)
Anticipatory postural response
FEEDFORWARD / PREPROGRAMMED response to counteract forgeable perturbation
Short latency
Can be triggered by a stimulus
Occur before the actual voluntary movement begins
Compensatory postural response
Learned response triggered by FEEDBACK mechanisms to counteract perturbation
Short latency
Amp of response = amp of perturbation
3 kind of cells invoked in central pattern generators
- Rhythmic or fatigable cells
- Inhibitory cells
- Modifying cells
