Flashcards in Exam 2 Study Guide 6 Deck (28):
How is the SC organized?
by region (cervical, thoracic, lumbar, sacral, cauda equina)
How are SC segments identified?
by same designation as their corresponding spinal nerves
1 segment = 2 vertebrae and the disc between them
What are SC segments named for?
vertebral level where they exit the vertebral canal
What structures comprise the spinal region?
all neural structures contained within the vertebrae
- spinal cord
- dorsal roots
- ventral roots
- spinal nerves (brief)
What structures comprise the spinal cord?
- grey matter
- white matter
- rexed lamina
- blood supply
CSF located here
organization of motor axons exiting the spinal cord
ventral rootlets form a ventral root
dorsal root contains
sensory axons that bring info to the SC and enter it via rootlets
large diameter sensory fibers (function)
proprioception and touch info
Where are large diameter sensory fibers found?
small diameter fibers (function)
pain and temperature
Where are small diameter sensory fibers found?
Dorsal horn processes:
Lateral horn processe:
Ventral horn processes:
Most of the gray matter of the SC is composed of
Where are lateral horns found?
What is a spinal nerve?
joining of a dorsal and ventral root in the IV foramen
carry all sensory and motor of a single spinal segment
What are Rexed's laminae?
functionally and structurally distinct areas of spinal cord gray matter
tract: Contralateral fractionation of movement, particularly of hand movements
tract: Control of neck, shoulder and trunk muscles
tract: Facilitates contralateral upper limb extensors
tract: Facilitates postural muscles and gross limb movements
tract: Adjusts activity in neck and upper back muscles
tract: Ipsilaterally facilitates LMN’s to extensors, inhibits LMN’s to flexors
tract: Enhances the activity of interneurons and LMN’s in SC
recurrent inhibition causes inhibition of these groups