sem 2 neuroclin 1

• - C5
• - monosynaptic

• -C6
• - monosynaptic

• -C7
• -monosynaptic

• - L4
• - monosynaptic

• -S1
• -monosynaptic

- innervate EXTRAfusal muscle fibers

• - innervate INTRAfusal muscle fibers
• - regulates sensitivity of muscle spindle so sensitivity can be maintained throughout contraction
• - under supraspinal control
• - can regulate muscle tone

- sensory axons in muscle spindles of proprioception

- sensory axons of proprioception in golgi tendon organs

• -1a sensory neuron synapses directly on alpha MN in spinal cord (monosynaptic)
• -accompanied by reciprocal inhibition of anatgonist muscles (poly synaptic)
• -aka deep tendon reflex, stretch reflex

• -1b sensory neuron synapses on interneuron in spinal cord which INHIBITS alpha MN
• - responds to muscle tension to prevent tears by inhibition of alpha MN
• - inhibitors polysynaptic

• -polysynaptic, excitatory tht involves many levels of the spinal cord
• -C or 1 delta axonal input
• - withdrawl response from nociceptive stimuli
• - crossed extensor reflex often accompanies

• - often in combo with withdrawl reflex
• - complex, polysynaptic
• - activation of extensor muscles and inhibition of flexors on opposite side of nociceptive stimuli
• - upper and lower limbs exhibit
• - "step on a nail, nail leg withdrawls, non-nail leg stiffens to take on extra load

• - NO SYNAPSES, TRAVELS AWAY FROM SPINAL CORD (antidromically)
• - thought to spread vasodilation

• -series of involuntary muscular contractions due to sudden stratching
• - result of UMN lesions

-PCA and posterior choroidal branches from the PCA

• -CN VII (ventral cell group)- supply muscles of the lower quadrant of the face
• -CNXII- genioglossus muscle
• -CN XI- trapezius and SCM

• - origin-pons
• -decussation- none
• -termination- lamina 8
• - function- action on gamma MN, increase muscle tone and enhance antigravity reflexes

• -origin: red nucleus of midbrain
• - decussation: midbrain
• - terminate- lamina V-VIII (cervical cord)
• - innervate flexor muscles (functionally parallel to CST)

• origin: LV nucleus of medulla
• decussation: none
• terminate: lamina VII and VIII
• function: alpha and gamma MN that innervate extensor muscles, maintain posture, modulated by Cb

• - inferior Cb peduncle
• - ST tract
• - sympathestic fibers
• - nucleus ambiguous
• -nucleus solitarius

• - middle Cb peduncle
• -vestibular nuclei
• -spinal V nucleus and tract
• -ST tract
• - descending sympathetic fibers

- superior Cb peduncle and Cb

-CN III, IV and V (V1, V2, V3)

• - proximal arm and leg weakness
• - often include trunk and proximal limbs

problems with visual processing

• - afferents from muscle spindles/joint receptors
• -enter ant. Cb as mossy fibers via peduncles
• -corollary motor fibers also enter from rubrospinal tract
• -DCN computes and decides
• - globoform and emboliform nuclei send modify signal to reticulospinal and rubospinal tracts for motor output (signal does not enter cortex)

• -afferent sensory from cortex(world) and corollary motor (intention) also enters posterior lobe of Cb
• - DCN computes
• - dentate sends info to VL to cortex to modulate corticospinal= precesion and sequence

• -afferent from vestibular apparatus enter flocculonodular lobe
• - DCN computes
• - Fastigial nucleus sends modulation to change position of eye and trunk in response to head movement

- medial deviation of an eye

-optic nerve-tract-chiasm-LGN-redaition- visual cortex (17) in occipital lobe

• - part of the medial temporo occipital lobe associated with face recognition
• - damage results in posopagnosia- inability to recognize faces

- M ganglion in the parietal lobe= 'where p/w'

- P ganglion in the temporal lobe= 'what p/w'

-retinol ganglion cells- SCN- paraventricular nucleus- spinal cord- sympathetic trunk- superior cervical ganglion- pineal gland

• -alpha (eyes closed) to theta (N1)
• - loss of most muscle tone and awareness of external environment
• - myoclonus and hypnogonic hallucinations

• - K-complexes and sleep spindles
• -occupies most (45-55%) of total sleep in adults
• - total loss of awareness of external environment

• - delta wave (min 20%)
• - may have night terrors, bed wetting, sleep walking and sleep talking

• - Beta wave sleep (beta waves also seen during awake)
• - muscular atonia and dreaming
• -20-25% total sleep

• - small irregular pupil that does not constrict to light, but does for accomodation
• - commonly caused by neurosyphilis

• light in affected eye will not cause constriction in either eye
• - afferent CN III disfunction
• - light in unaffected eye will cause constriction in both

• - aka "tonic pupil"
• - caused by degeneration of the ciliary ggl and postganglionic parasympathetic fibers
• - light reaction shows prolonged and sluggish constriction
• - near reaction occurs, but pupil remainns constricted and dilates slowly