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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.