part 4 Flashcards
somatosensory system
dominant sensory sytem (70%)
Fast input
self to supporting surface
relation of one limb/segment to another
components of somatosensory system
muscle spindle fibers (muscle length, rate of change)
Golgi tendons organs (monitor tension)
joint receptors (mechanorecptors)
cutaneous receptors
neural pathway
spinal cord- Dorsal horn
contralateral ( sides from L-R)
brainstem
thalamus
Parietal cortex (superior lower body, inferior upper body)
how do golgi receptors in tendons encode tension
same way as hair cells
Low spikes= low tension (low force)
high spikes= high tension (high force)
joint receptors
range of motion in joints percieved through integrated receptors in ligaments and joint capsules
Pacini receptors
dynamic sensitive to movement of joint capsule and ligaments during ROM
Ruffini receptors
static sensitive to position
visual system
10% info
reports information: self to supporting surface and head position
components of visual system
eyes, visual tract, thalamic nuclei, visual cortex
vertical eye movements are generated and controlled by
mid-brain
horizontal eye movements are generated and controlled by
pons
Extraocular muscles
6 total
superior and inferior oblique
superior, inferior, medial and lateral rectus
what muscles rotate eye in orbit
superior and inferior oblique
what muscles are innervated by CN III
superior inferior and, medial recti and inferior oblique
what is CN III
oculomotor nerve
whaat muscles are innervated by CN IV
superior oblique
what is CN IV
trochlear nerve
what muscles are innervated by CN VI
lateral rectus
agonist
yoked pairs between eyes to generate conjugate eye movements
what is CN VI
abducens
Oculomotor nerve
CN III
- dorsal midbrain
2 divisions:
superior: superior rectus
inferior: inferior, medial recti and inferior oblique
Trochlear nerve
close to dorsomedial face of midbrain
enters the superior obrital fissure: superior oblique
abducens nerve
CN VI
enters superior orbital fisure: ipsilateral lateral rectus
medial longitudinal fasciculus (MLF)
located in dorsal midbrain
carries ocular motor and vestibular signals between medulla (abduces nucleus) and midbrain (ocular motor nucleus)
- lateral gaze
