1. Spinal cord - reflexes
Dr. Altdorfer
tract

2. Kahler

3. Ascending (right) and Descending (left) Tracts of the Spinal Cord3

5. The most mobile parts of the spinal cord are the most vulnerable for injury and degeneration.
In the cervical region the cervical enlargement almost completely fill the vertebral canal: the smallest displacement of the vertebrae will result in damages of the spinal cord..
The lumbar region is loaded with almost the complete weight of the trunk – leading to frequent degenerative disorders (disc herniation, spondilosis).
Cervical myopathy is compression of the spinal cord
The cord get squeezed
And this causes numbness and /or weakness
in the arms and legs

6. Disc herniation
Radiculopathy:the location of the symptoms helps determine diagnosis
Symptoms of spinal nerve injury. Pain or sensory loss of the given dermatome, weaker or missing reflexes and paresis of the muscles innervated by the spinal nerve affected. The most commonly injured segments are: L4, L5, S1

7. Dermatomes

8. Clinically important monosynaptic reflexes
Effector-Muscle
Segment
Bicepsreflex
M. biceps brachii
C5-C6
Tricepsreflex
M. triceps brachii
C6-C7
Patellareflex
M. quadriceps femoris
L2-L4
Achillesreflex
M. triceps surae S1
Masseterreflex
M. masseter
Brainstem
(pons-mesencephalon)

9. In case of complete transsection of the spinal cord, there is a complete sensory loss under the damage, on both side, and complete paresis including all the muscles! If the site of the damage is above C4 segment the patient could die (phrenic n!).

10. Brown-Séquard Syndrome
In case of hemisection of the spinal cord (Brown-Séquard syndrome)
-heat, pain and basic touch information is lost under the damage on the opposite side
-epicritical sensitivity is lost under the damage on the same side.

11. Spinal reflexes
Stretch reflex (or monosynaptic, proprioceptive, myotatic)
Withdrawal reflex (or polisynaptic, nociceptive, flexor…)
Autonomous reflex (or vegetative)
Receptor
Sensory neuron
(Interneuron)
Effector neuron
Effector organ

12. Spinal reflexes
Stretch reflex (or monosynaptic, proprioceptive, myotatic)
Withdrawal reflex (or polisynaptic, nociceptive)
Autonomous reflex (or vegetative)
Receptor
Sensory neuron
(Interneuron)
Effector neuron
Effector organ

13. Nociceptive reflex arc
Synonyms: flexor reflex, withdrawal reflex, polysynaptic spinal reflex
Ancient reflex that protects the body from potentially damaging, noxious stimuli.

14. Nociceptive reflex arc
Nociceptors of the skin and mucous membranes →
A delta and/or C fibres →
DRG (ganglion) →
spinal cord: dorsal horn → interneuron
numerous collaterals: excitacion of motoneurons of flexors and inhibition of extensor on the side of stimulus and stimulation of extensors together with inhibition of flexors on the contralateral side (flexor reflex with crossed extensor response).

15. Spinal reflexes
Stretch reflex (or monosynaptic, proprioceptive, myotatic)
Withdrawal reflex (or polisynaptic, nociceptive)
Autonomous reflex (or vegetative)
Receptor
Sensory neuron
(Interneuron)
Effector neuron
Effector organ