Vestibular System Flashcards
Endolymph is secreted by
Cochlear duct
Endolymphatic duct drains into
Dural sinus
Perilymph drains from _______ and _________
Capillaries and CSF
Perilymphatic duct drains into the
Subarachnoid space, into the dura, and into the CSF
Different regions of the membranous labyrinth
Semicircular canals, utricles, saccules
Different regions of the membranous labyrinth
Semicircular canals, utricles, saccules
Cupula is epithlium of sterocilia that project into
Gelatinous mass
Crista is sensitive to motion of
Endolymph
Crista is sensitive to this acceleration
Angular acceleration
Macula of saccule and utricle are this
Cilia that project into gelatinous matrix. Contain otoliths (calcium carbonate stones)
Movement of otoliths occur due to
Linear acceleration without endolymphati movement
Movement of otoliths occur due to
Linear acceleration without endolymphati movement
Macula detects movement in this plane;
Utricles detects movement in this plane
vertical;
horizontal
Vertigo is caused by this
acoustic neuroma, meniere’s disease, benign paroxysmal positional vertigo–
Loss of equilibrium
Vertigo is caused by this
acoustic neuroma, meniere’s disease, benign paroxysmal positional vertigo–
Loss of equilibrium
Meniere’s Disease is caused by
Escess secretion and decreased drainage of endolymph- the labyrinth becomes dialated. Epithelia and receptor cells get stretched
Symptoms of Meniere’s Disease
Sensorineural hearing loss, tinnitus, vertigo, fullness in the ear
Benign Paroxysmal Positional Vertigo (BPPV) is caused by
Otoliths from the utricle that all into semicircular canals
Conflict of these senses occurs in BPPV
Sensory input between dysfunctional vestiblar and normal somatosensory;
Visual and proprioception senses produce shift in position and body motion
VEstibuar nerve donducts vestibular activity to
Vestibular nuclei in brain stem (posture, eye movements); vestibulo-cerebellum (vestibular reflexes)
Dysfunction of vestibular system will not communicate correctly with
The brainstem
Dysfunction of vestibular system will not communicate correctly with
The brainstem
Vestibulo-Ocular Reflex does this
Adjusts eye movements to rotation of head to fix gaze on a visual object
Nerves in vestibulo-ocular reflex
Abducens VI - horizontal semicircular ducts- turns head to the left;
Oculomotor nuclei III - turns eye to the right
Nystagmus is this
Involuntary saccadic movement when the eyeball is moving
Pahotological vs physiological nystagmus
Physiological- norma part of scanning; pathological- eyes are still flicking unnecessarily. Problem in semicircular canals, utricle, saccule, or vestibulo-cerebellum
Posture is a pathway that descends from
Vestibular nuclei of the brain
This provides precision for posture control
Cerebellum
Vestibulo-sympathic reflex enhances this vascular action
Enhances vasoconstriction- to protect against synocpe during postural changes or emotional stress
To increase MAP due to postural changes, this occurs
increased otolithic activity enhances sympathetic activity to blood vessels in skeletal muscles and kidney
Sacroutrical regions detect this movement when you stand up
Vertical movement- they act to control sympathetic activity– vestibular system works with baroreceptor system
Vestibulo-sympathetic reflex increases this during nausea
vasoconstriction and sweating
Vestibular nuclei controls
RVLM
In addition to skeletal muscle, this organ is affected by the vestibulo-sympathetic reflex
Kidney- very reactive to changes in blood flow
Vestibulo-parasympathetic reflex acts to do this with blood flow
Restores cerebral blood flow after BP drop (orthostatic hypotension)
- MAP: baroreceptor vasoconstriction
- Cerebral blood flow: vasodilation of cerebral vessels
Vestibulo-parasympathetic reflex is activated in this pathway
Solitary nucleus, pterygopalatine (parasympathetic) ganglion–>vasodilation
Visual, tactile, and vestibular input allow for this
First-person perspective
