SPINAL CORD & INJURIESDr. Ayisha Qureshi

1. In the space provided write the names of the Ascending & Descending Tracts of the Spinal Cord.

ASCENDING TRACTS DESCENDING TRACTS1. Anterolateral system(Anterior & Lateral

Spinothalamic Tract)(pain, temperature, crude touch, itch and tickle)

2. Dorsal Column Medial Lemniscus system(touch, 2-point discrimination, proprioception, pressure and vibration)

3. Spinocerebellar (anterior & posterior)(proprioception, position and posture, movement of voluntary muscles)

4. Spino-olivary(proprioception)

5. Spinotectal(spinovisual reflexes)

6. Spinoreticular(consciousness & awareness)

1. Corticospinal Tract (anterior & Lateral)(voluntary motor movements)

2. Vestibulospinal Tract (anterior & Lateral)(Regulate the anti-gravity muscles and are responsible for maintaining posture and balance)

3. Reticulospinal Tract(Regulates posture and muscle tone)

4. Tectospinal Tract(control of head & eye movements, in response to visual & auditory stimuli)

5. Rubrospinal Tract(Controls voluntary movements of the distal group of muscles)

6. Olivospinal Tract(reflex movements arising from proprioceptors)

7. Label the ascending & descending tracts in the sketch below. Also label the anterior horn, posterior horn and the lateral horn. What are the contents of each horn?

8. Complete the information required for the Tracts listed:

Tract Origin Termination Function Crossover/ Uncrossed

Descending/ Ascending

LATERAL CORTICOSPINAL

Cerebral cortex

Anterior horn of spinal cord

on alpha motor neurons

Voluntary movements of the neck, trunk & upper limb

Crossed Descending

RUBROSPINAL Red nucleus

Anterior horn of spinal cord

on aloha motor neurons Movement

coordinationCrossed (at midbrain) Descending

SPINOTHALAMIC

From Cutaneous receptors & then

enter the Spinal cord

Cerebral cortex

Pain, touch, temperature, light touch, itch & tickle

Crossed Ascending

DCMLFrom

spinal cord

Cerebral Cortex &

cerebellum (only for the

proprioceptive fibers)

Touch, Two-point

discrimination, pressure, vibration&

proprioception

Crossed Ascending

TECTOSPINALSuperior colliculus

Cranial nerve nuclei in

Medulla & alpha motor neurons in spinal cord

Movement of head & neck

in response to visual & auditory reflexes.

Crossed Ascending

ANT. SPINOCEREBELLAR

Spinal cord Cerebellum Proprioception

Some crossed &

some uncrossed.

Descending

VESTIBULOSPINAL VestibularNucleus

Anterior horn of spinal cord

on alpha motor neurons

Maintenance of upright posture & balance

Uncrossed Descending

RETICULOSPINAL Reticular formation

Anterior horn of spinal cord

on gamma motor neurons

Muscle tone, posture

Some crossed,

some uncrossed

Descending

9. Define Upper Motor Neurons: are motor neurons arise from the cerebral cortex and the brainstem and synapse on the lower motor neurons (either directly or via local interneurons).

10. Using the diagrams, show the location of the various diseases mentioned below:

SYRINGOMYELIA It is a chronic disease of the spinal cord usually affecting the cervical part; it is characterized by the presence of fluid-filled cavities and gliosis in the spinal cord. There is destruction of gray matter of the anterior and posterior horns of the spinal cord but the fibers crossing in the anterior gray commissure may also be destroyed

TABES DOSALIS It is a slowly progressive nervous disorder caused due to the degeneration of posterior (sensory) nerve roots. It usually occurs in syphilis.Posterior nerve roots are affected proximal to theposterior root ganglia. Ganglia are not affected. However, fibers in the Dorsal Column are also affected.

COMPLETE TRANSECTION OF THE SPINAL CORDComplete Transection can occur due to bullet injury, an accident causing dislocation of spinal cord or occlusion of blood vessels. The effects occur in three stages:1. Stage of spinal shock.2. Stage of reflex activity.3. Stage of reflex failure.