Labyrinth - AnswersThe cochlea and the vestibular organ combined
Cochlea - AnswersHearing, tinnitus, pressure or pain in the ear
SCCs
How many?
What is at the base of each canal?
What are SCCs filled with?
What do SCCs articulate with?
How do SCCs work? - Answers3 SCCs
Ampulla is at the base of each canal
SCCs are Filled with endolymph
Articulate with the utricle, NOT the saccule
Each side works together, so the R anterior SCC is in the same plane as the L posterior SCC (when R
anterior is excited, L posterior is inhibited). Canals work in functional pairs
Ampulla
What are they? Where are they? What do they contain? - AnswersAt the base of each SCC, contain cilia
that help detect angular acceleration/deceleration
Cilia are embedded in the membrane called the Cupula
Hair cells are aligned from shortest to tallest
What do SCCs detect? - AnswersAngular acceleration/deceleration
,Cilia- what is i? where is it? what does it do? - AnswersEmbedded in the membrane called the cupula,
they help detect angular acceleration/deceleration
Cupula - Answersa gelatinous mass found in the ampulla of the semicircular canals; moves in response
to the flow of the fluid in the canals, the cilia are embedded in this
Kinocilium - AnswersThe tallest hair cell
Moving towards the kinocilium - AnswersExcitatory
Moving away from the kinocilium - AnswersInhibitory
Otolith organs
What are they?
What do they detect?
What plane do they sit in? - AnswersUtricle and Saccule
Detect linear acceleration/deceleration
Otoliths ARE gravity sensitive (SCCs are NOT gravity sensitive)
Utricle sits in the horizontal plane (can detect a car accelerating quickly)
Saccule sits in the vertical plane (can detect elevator motion going up and down)
Hair cells in the Otolith Organs
Where are they?
What is on top of them?
What does this help detect? - AnswersEmbedded in the Otolithic Membrane
Overlying this membrane are the Otoconia
Otoliths sense where the head is in space (tilt in relation to upright and gravity)
Dark Cells - AnswersMaintain homeostasis within the endolymph
,Potassium and Calcium homeostasis
Might help degrade loose otoconia - can help with resolution of BPPV
Meneire's Disease has a reduction of Dark Cells - this is likely why BPPV is more common in this
population
Labyrinthitis - also a loss of Dark Cells - BPPV is also more common in this population
Nystagmus - what is it named by? - AnswersThe direction of the FAST movement of the eyes
The fast phase beats towards the more intact/active side, slow phase beats towards the impaired or
hypoactive side
Postural control
Control by Vestibular Mechanisms vs
Control by Somatosensory Cues - AnswersVestibular mechanism control neck, trunk and hip muscles to
stabilize the head. Vestibular mechanisms control more proximal things. So Vestibular does more hip
strategies
Somatosensory cues are more responsible for activation of distal muscles. Somatosensory does more
ankle strategies
Meds for Vestibular Issues
Types?
Categories?
, Purpose?
Names?
When are they indicated? - AnswersBenzodiazepines:
Diazepam- Valium
Lorazepam- Ativan
Indicated for acute or severe vertigo
Antihistamines:
Meclizine- Antivert
Indicated for chronic vertigo
Antiemetics:
Zofran
Scopolamine
Indicated to reduce emesis
Acute Unilateral Peripheral Vestibulopathy-
Signs and symptoms?
Onset?
How long does it last?
How and why does it go away?
Medication indication?
What speeds up recovery?
Prognosis? - AnswersSpontaneous onset
Continuous vertigo
Vertigo lasts 1 day to 1 week, NOT longer than 1 week