Compensatory Eye Movements John Simpson Functional Classification of
- Slides: 39
Compensatory Eye Movements John Simpson
Functional Classification of Eye Movements that stabilize the eye when the head moves Vestibulo-ocular Uses vestibular input to hold images stable on the retina during brief or rapid head movement Optokinetic Uses visual input to hold images stable on the retina during sustained or slow head movement Movements that keep the fovea on a visual target Saccade Brings new objects of interest onto the fovea Smooth Pursuit Holds the image of a moving target on the fovea Vergence Adjusts the eyes for different viewing distances in depth
Cupula and otoliths move sensory receptors Cristae Maculae
Angular Acceleration Angular Velocity Angular Position Cupula Deflection
Canal afferents respond to cupula motion
Canal afferents code velocity • Spontaneous activity allows for bidirectional signaling • S-curve is common • Different cells have different ranges and different dynamics • Population code
Cupula and otoliths move sensory receptors Cristae Maculae
Classes of eye movements • Reflexive – gaze stabilization – VOR • Stabilize for head movements – Optokinetic • Stabilize for image motion • Voluntary – gaze shifting – Saccades • Acquire stationary target – Smooth pursuit • Acquire moving target – Vergence • Acquire target in depth
VOR With and Without Vision
r. VOR gain varies with frequency • Almost perfect > 1 Hz • Low gain for low frequencies (0. 1 Hz) • Sensory mechanisms can compensate (optokinetic reflex)
Optokinetic reflex • Optokinetic nystagmus • Neural pathway (AOS) convergent with VOR
Oculomotor muscles and nerves • Oculomotor nerve (III) – Medial rectus – Superior/Inferior recti – Inferior oblique • Trochlear nerve (IV) – Superior oblique • Abducens nerve (VI) – Lateral rectus
The 3 -Neuron Arc Primary Effects of Canals on Eye Muscles Canal Excites Inhibits Horizontal Ipsi MR, Contra LR Ipsi LR, Contra MR Anterior Ipsi SR, Contra IO Ipsi IR, Contra SO Posterior Ipsi SO, Contra IR Ipsi IO, Contra SR
Secondary Effects of Canals on Eye Muscles
19. 3 Organization of the cranial nerve nuclei that govern eye movements.
19. 7 Synaptic circuitry responsible for horizontal movements of the eyes to the right.
Translational VOR • Compensates for change in head position with respect to gravity • Compensates for linear motion as opposed to rotational motion
- Simpson's diversity index example
- Various axial movements
- Nerve supply to superior oblique
- Two type of physical fitness
- Doll's eye
- Orthomode transducer tutorial
- Dispensatory measures
- Compensatory response theory
- Karakteristik teori keperawatan
- Compensatory education policies
- Compensatory skills
- The function of the compensating curve is
- Wholly compensatory system examples
- Scdnt
- Mpkp jiwa
- Remedial vs compensatory approach occupational therapy
- Compensatory exercises
- Compensatory mechanism of heart failure
- Model konseptual keperawatan keluarga
- Compensating and balancing extractions
- Heart cross section
- Theories of distributive justice
- Compensatory justice examples
- Hammurabi mesopotamia
- Birds eye view angle
- Eye for an eye code
- Anemic eyes pictures vs normal
- Hammurabi's code activity
- An eye for an eye a tooth for a tooth sister act
- Explain the image
- An eye for an eye meaning
- Behold he is coming
- Cyanopsin color
- Classification of space maintainers
- Non functional plasma enzymes
- Plasma enzymes
- Functional and non functional
- Functional classification of neurotransmitters
- Classification of functional styles
- Structural and functional classification of joints