Vestibular + proprioception

Question 1

true/false-membranous labyrinth floats in endolymph and is filled with perilymph.

Answer 1

false, it’s floating in perilymph and filled with endolymph.

Question 2

how are perilymph and endolymph secreted and drained?

Answer 2

peri is secreted by arterioles in periosteum and drained via perilymphatic duct in cochlea aqueduct in temporal bone. endo is secreted by tissues in cochlear duct and drained by endolymphatic duct in vestibular aqueduct in temporal bone.

Question 3

whats the cause of Meniere’s disease and Labyrinthitis?

Answer 3

excess pressure in peri and endolymph.

Question 4

what are the otholith organs and where are they located?

Answer 4

they are utricle and saccule and located in vestibule.

Question 5

what types of movements do utricle and saccule detect?

Answer 5

linear. utricle in horizontal/transverse plane, saccule in sagittal. hair cells located on horizontal floor and medial wall respectively.

Question 6

what are the receptive tissue patches in otolith organs called?

Answer 6

maculae utriculi and sacculi

Question 7

true/false, otolith organs are responsive to changes in endolymoh direction.

Answer 7

false, they respond to gravity

Question 8

true/false, the ampulae in semicircular canals contain maculae as their neuroepithelium

Answer 8

false, macula is for otolith, semicircular canals have crista.

Question 9

whats gives the heavy weight of otholith organs?

Answer 9

the calcium carbonate otoliths scattered on otolithic membrane.

Question 10

what are the types of sensory hair cells in vestibular system?

Answer 10

flask shaped, and cylinder shaped.

Question 11

where are the cell bodies of the vestibular sensory neurons located?

Answer 11

in the vestibular ganglion within internal auditory meatus.

Question 12

where are the sensory receptors for proprioception located?

Answer 12

muscle spindle and golgi tendon organs

Question 13

axon type for proprioception of golgi and muscle spindle?

Answer 13

golgi-1b,

spindle 1a

Question 14

types of intrafusal muscles?

Answer 14

nuclear chain fibres and nuclear bag fibres

Question 15

types of afferents to intrafusal fibres?

Answer 15

annulospiral endings-primary type 1a axons, flower-spray endings-type 2a

Question 16

in the spinal cord the type 1a axons from annulospiral ending synapse with……which provide motor input to extrafusal.

Answer 16

alpha motor neurons

Question 17

what is friedreich’s ataxia associated with ?

Answer 17

the atrophy of spinocerebellar pathways and hypoplasia of sc and DRG.

Question 18

from what parts of body does the dorsal spinocerebellar tract get info and where does it synapse?

Answer 18

trunk and lower limbs below T6. synapses in clarke’s nucleus which is present from c8-L2, within lamina 7.

Question 19

what info does anterior spinocerebellar tract carry and where does it synapse?

Answer 19

muscle tension from lower limb and trunk below L3, also attempted movement, synapses in lamina 5-7

Question 20

what info does the cuneocerebellar tract carry and where does it synapse?

Answer 20

muscle stretch and tension from upper limb and trunk, above c8, synapse in lateral cuneate nucleus -exist above T6.

Question 21

what info does rostral spinocerebellar carry and where does it synapse?

Answer 21

muscle tension of upper limb and trunk, above C8, synapses in lamina 7.