The Nervous System 3 - bpums.ac.ir

The Nervous System 3The Nervous System 3

Dr. AlmasiAutumn 1388
















S i l Whi MSpinal White MatterSensory Nerve Tracts

(Ascending or Afferent)(Ascending or Afferent)Motor Nerve Tracts

(Descending or Efferent)




S N i lSensory Nerve impulses

DestinationRouteReceptor

To parietal lobe of Cerebrum

N1: to spinal cord by post. rootN2: decussation on entering spinal cord then in antlateral spinothalamic tract to N3: Thalamus

Pain, touch, temperatureCerebrumspinothalamic tract to N3: Thalamus

To parietal lobe of Cerebrum

N1: to medulla in posterior funiculusN2: decussation in medulla, transmition to N3: ThalamusTouch, proprioceptors

NNo decussation, to Cerebellum in posterior spinocerebella

N1: to spinal cordN2: to CerebellumProprioceptors

pr tract


Voluntary Muscle Movement (from the Brain to the Muscles)

• The upper motor neuroneThe upper motor neuronePrecentral sulcus area (Betz Cells)/Int. capsul/brain

stem/ spinal cord (Lat Corticospinal tracts)/ Lowerstem/ spinal cord (Lat. Corticospinal tracts)/ Lower motor neuron (Ant. horn of gray matter)

• The lower motor neuronThe lower motor neuronAnt. horn of gray matter (Ant. Root)/ +Sensory

fibers(Mixed Spinal Nerve)/ Intervertebral foramen/fibers(Mixed Spinal Nerve)/ Intervertebral foramen/ [motor end-plate + muscle fiber]: Motor unit, acethylcholine


Involuntary Muscle MovementInvoluntary Muscle Movement

• Lower Motor NeuronLower Motor Neuron• Spinal Reflexes

S h R fl• Stretch Reflexes• Autonomic Reflexes






Documents

The Nervous System 3 - bpums.ac.ir