Chapter-17: The Spinal cord

Question 1

The overall functions of the spinal cord

Answer 1

• Contains neural circuits that control some of your quickest reactions to environmental changes (reflexes).
• Is the site for integration of neuronal stimulation
• Relays sensory nerve impulses (highway).
• Is continuous with the brain, and together they constitute the central nervous system (CNS).

Question 2

The names of the meninges, their sequence, and functions

Answer 2

Dura mater

• most superficial
• dense, irregular connective

Epidural space
a space between the dura mater and the wall of the vertebral canal.

Arachnoid mater

• is middle layer
• avascular covering
• contain delicate collagen fibers and some elastic fibers, and cells.

Subdural space
-between the dura mater & the arachnoid & contains interstitial fluid

Pia mater

• inner most
• highly vascular
• transparent connective tissue
• adheres to surface of spinal cord and brain
• thin squamous to cuboidal cells
• intelacing bundles of collagen and elastic fibers

Question 3

The structure and function of the white mater (white columns)

Answer 3

• consists of bundles of myelinated axons of sensory neurons, interneurons, and motor neurons
• white because of the fatty substance (myelin)
• acts as an electrical insulation
• messages to pass quickly from place to place.

Question 4

The structure and function of the gray matter (gray horns)

Answer 4

-letter H or a butterfly shape structure surrounded by white matter.

Anterior (ventral) gray horns
-contain clusters of cell bodies of somatic motor neurons that provide nerve impulses for contraction of skeletal muscles.

Posterior (dorsal) gray horns
-contain cell bodies and axons of interneurons as well as axons of incoming sensory neurons

Lateral gray horns
-The lateral horns contain the cell bodies of autonomic motor nuclei that regulate activity of smooth muscle, cardiac muscle, and glands.

Question 5

Roots of the spinal nerve and which one is sensory and motor

Answer 5

Spinal nerve 
post (dorsal) root 
SENSORY
mixed sp nerve
spinal nerve trunk
ramus
post dorsal ramus
deep muscles of skin and post surface of trunj

spinal nerve
anterior (ventral root)
MOTOR
mixed spinal nerve
spinal nerve trunk
ramus
ant (ventral) ramus
upper and lower limb muscles 
muscles of lateral and anterior region of trunk

Question 6

Figure 2: Transverse section through the Spinal Cord.

Answer 6

Figure 2: Transverse section through the Spinal Cord.