Post on 01-Nov-2021
The Nervous System 3The Nervous System 3
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
S i l Whi MSpinal White MatterSensory Nerve Tracts
(Ascending or Afferent)(Ascending or Afferent)Motor Nerve Tracts
(Descending or Efferent)
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
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
Dr. AlmasiAutumn 1388
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
Dr. AlmasiAutumn 1388
Involuntary Muscle MovementInvoluntary Muscle Movement
• Lower Motor NeuronLower Motor Neuron• Spinal Reflexes
S h R fl• Stretch Reflexes• Autonomic Reflexes
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388
Dr. AlmasiAutumn 1388