Midterm Exam Anatomy Flashcards
Causes of Vestibular Disorders
- Head Trauma
- Otitis Media
- Bacterial Labyrinthitis
- Ototoxic Medications
- Ischemia
- Vestibualr Schwanomma
- Endolymphm Hydrops (menieres)
Know 5 from above
Dizziness is ___ complaint of people over ___ years
Dizziness is the #1 complaint for people over 70 years
85% of true vertigo is dysfucntion of what?
85%. of true vertigo is dysfunction of the inner ear
What % of people over the age of 70 experience BPPV
50%
What is the leading cause of TBI’s & Fractures
Falls are the leading cause of brain injury (TBI’s) and fractures
What is the 6th leading cause of death in the elderly
Falls are the 6th leading cause of death in the elderly
what is true vertigo?
True vertigo is when the room/enviorment is spinning or you/self is spinning
What is the likely point of origin for true vertigo
True vertigo is likely peripheral (inner ear)
Maintaining balance is dependent on what?
Balance is dependent on sensory information gathered from visual, somatosensory & Vestibular receptors in the body
What the stages of the balance process tranmission?
- Sensory information from the visual, somatosesnory & vestibualr is picked up by their receptors
- It is then sent to the brainstem
- Brainstem integrates info
- sent to the Cortex for perception & Processing.
What streamlines the balance processs?
The Cerebellum & Cerebral Cortex streamline the process by coordinating incoming impulses & adding info from thinking & memory
Balance
__________ information is constantly changing as a fucntion of movement.
Visual & Somatosensory
Balance
_____ is always the same
Vestibular (gravity) is always the same.
Define Peripheral
Inner ear (labyrinth & 8th nerve up to the point it enters the braistem
Define Central
CNS
(brainstem to cortex)
Vision Denied
Eyes closed/covered
Patient is without visual target
Vision Allowed
Eyes open/uncovered
Patient is with visual target, able to fixate
Name the two sensory structures within the Peripheral Vestibular system
Semicircular canal - Cristae Ampullaris
Otolithic Organs (utricle & saccule) - Maculae
SCC detect ____ _____ of the head/body
SCC detect angular acceleration of the head/body
corresponding movement
Pitch
Shake head yes
Shake Head yes
Pitch
Yaw
Shake head no
Shake head no
Yaw
Roll
Tilt head to the side
tilt head to the side
Roll
what does it mean when i say SCC Function in a complimentary ‘push - pull’ fashion with opposite ear
- Two ears work together in balance detection
- When one ear is excitatory teh opposite is inhibitory
- turn head right - right SCC = excited. at the same time left SCC = inhibited
what are the Otolithic Organs
Utricle & Saccule
Detects linear acceleration in the horizontal plane & tilt
moving forward in a car or side to side
Utricle
Detects linear acceleration in the vertical plane
going up or down in an elevator
Saccule
Plays a role in sensing gravity and head orientation.
Name the parts of the cochlea
- outer wall = Bony labyrinth
- Membranous labyrinth - suspended in endolymph
- Utricle & Saccule - otoconia
- Vestibaulr hair cells
- SCC (3)
- Vestibular hair cells
- Cristae in ampulla
- on top of cristae = cupula.
The outer wall of the labyrinth is called what?
The bony labyrinth and is filled with perilymph
Bony Labyrinth filled with what?
Perilymph
Inside the bony labyrinth is what?
Inside the bony labyrinth & suspended in perilymph is membranous labyrinth
The membranous labyrinth is filled with what?
Membranous labyrinth filled with endolymph
Membranous labyrinth is suspened in what?
Membranous Labyrinth suspended in perilymph
Name the 5 sensory organs housed within the membranous labyrinth
- Utricle macula
- Saccule Macula
- Three Cristae Ampullaris
Plays a large role in postural control and primarily senses changes in orientation with respect to gravity
The utricle plays a large role in postural control and primarily senses changes in orientation with respect to gravity.
important for maintaining balance and keeping the body in the correct posture
The utricle is important for maintaining balance and keeping the body in the correct posture
What is the utricles function
- The utricle is important for maintaining balance and keeping the body in the correct posture
- Detects linear acceleration in the horizontal plane
What is Saccules function
- It is connected though the vestibular aqueduct & no open communcation with utricle & SCC
- Detects linear acceleration in the vertical plane
What is the macula
- On macula is located in utricle and saccule
- consists of a layer of calcium carbonate crystals aka otoconia
what consists of a layer of calcium carbonate crystals aka otoconia
Macula
Anatomy of the utricle & saccule
- Macula (layer of otoconia)
- Otoconia
- Below otoconia- gelatinous membrane
- Vestibaular hair cells - stereocillia extend into the GM
- Otoconia shift due to head movement
Posterior canal shares a plane with ____
Posterior canal shares a plane with the contralateral anterior canal
Anterior canal is paired with ______
Anterior canal is paired with posterior canal of opposite ear
Horizontal canal shares a plane with____
Horizontal canals share plane
Left Anterior with ______
Left Anterior with right posterior
left posterior with ___
Left posterior with right anterior
left horizontal with ___
left horizontal with right horizontal.
What are the sensory cells in the SCC
cristae or cristae ampullaris
The sensory cell in the Otolithic Organs
maculae
what is the cristae and where is it housed?
- Cristae is the SCC sensory cell
- Housed within the ampulla (widening of the bony & membrance of canal)
Sitting atop the cristae is what
Sitting atop the cristae is membrane called cupula
Is the cupula sensitive to motion or gravity?
Cupula is exquisitely sensitive motion
The vestibular hair cells in the inner ear are stimulated when
The vestibular hair cells in the inner ear are stimulated when they bend in response to motion or changes in head position
Each vestibular hair cells has one ____ and several _____
Each vestibular hair cells has on kinocilium and several stereocilia
Movement that causes the stereocilia to flow towards the kinocilium =
Movement that causes the stereocilia to flow towards the kinocilium = depolarization & increases in electrical charge
When the stereocilia bend toward the kinocilium, the ion channels
When the stereocilia bend toward the kinocilium, the ion channels open, allowing positively charged ions (such as potassium) to flow into the cell. depolarizing the hair cells increasing activity
Movement that causes stereocilia to flow away from the kinocilium
Movement that causes stereocilia to flow away from the kinocilium = hyperpolarization & decreases in electrical potential
The stereocilia bend away from the kinocilium, the ion channels
if the stereocilia bend away from the kinocilium, the ion channels close, hyperpolarization occurs decreasing the electrical activity of the hair cell.
What canal
Endolymph movement towards the ampulla = Excitation
Endolymph movement away from the ampulla = Inhibitory
Horizontal
Name orientation of hair cells in the horizontal canal.
Name orientation of hair cells in the anterior canal.
Name orientation of hair cells in the Posterior canal.
Name canal
Endolymph movement towards the ampulla = Inhibitory
Endolymph movement away from the ampulla = Excitation
Anterior or Posterior
Name canal
Endolymph movement towards the ampulla = Inhibitory
Endolymph movement away from the ampulla = Excitation
Anterior or Posterior
____ Endolymph flow towards ampulla = Excitatory
______ Endolymph flow towards ampulla = Inhibitory
Horizontal Canal Endolymph flow towards ampulla = Excitatory
Anterior & Posterior Endolymph flow towards ampulla = Inhibitory
Vestibular Hair cells are oriented towards the striola in the ____
Vestibular Hair cells are oriented towards the striola in the utricle
Vestibular Hair cells are oriented away from the striola in the ____
Vestibular Hair cells are oriented away from the striola in the saccule
CN 8 Divisions
Utricle, anterior part of saccule, horizontal & anterior canals.
Superior Division
CN 8 Divisions
Posterior part of saccule, and posterior canal.
Inferior Division
CN 8 Divisions
Superior Division
Utricle, anterior part of saccule, horizontal & anterior canals.
CN 8 Divisions
Inferior Division
Posterior part of saccule, and posterior canal.
Superior Rectus CN
Cranial nerve 3, Elevates - raises eyes
LR6SO4 all the rest are 3
Inferior Rectus CN
Cranial Nerve 3, Depression - pulls down
Medial Rectus, CN
Cranial Nerve 3 Adducts - pulls towards nose
Lateral rectus CN
Cranial Nerve 6, Abducts - moves the eye away from the midline
Superior Oblique, CN
Cranial Nerve 4
- Intorsion (inward rotation) → The top of the eye rotates toward the nose.
- Down & Away
Inferior Oblique, CN
Cranial Nerve 3
- Extorsion (outward rotation) → The top of the eye rotates away from the nose.
- Up & Away
Name the eye Muscules for cranial nerve 3
- Medial Rectus
- Inferior Rectus
- Superior Rectus
- Inferior Oblique
Name the eye muscles for cranial nerve 6
Lateral Rectus
- moves eye away from midline
Name the eye muscle for cranial nerve 4
Superior Oblique
- intorsion; top of eye rotates towards nose
