nervous system: CNS spinal cord

Question 1

structure overview

Answer 1

-foramen magnum to level of lumbar vertebrae L1/L2 (conus medullaris)
-nerves continue down from spinal cord through vertebral foramina as cauda equina (horse’s tail)
(exit at intervertebral foramina)
-filum terminal
*CT=extension of pia mater -anchors conus medullaris of spinal cord to coccyx
*location where CSF samples taken

Question 2

Cross-sectional structure

Answer 2

• anterior median fissure and posterior median sulcus
• Central canal
• gray matter
• white matter

Question 3

-anterior median fissure and posterior median sulcus

Answer 3

separate cord into right and left halves

Question 4

central canal

Answer 4

contains CSF

Question 5

gray matter

Answer 5

cell bodies and dendrites of motor neurons, interneurons,

• H-shaped
• cross bar= gray commissure
• horns:
  1. dorsal horn=sensory
  2. lateral horn=motor
  3. ventral horn=motor

Question 6

white matter

Answer 6

myelinated axons =ascending (sensory) and descending (motor) tracts
forms columns:
1. dorsal column
2. lateral column
3. ventral column

Question 7

functions

Answer 7

-carries sensory and motor impulses
-produce reflexes
(fast, predictable, automatic responses to changes in the environment)
eg. withdrawal reflex