CNS - Spinal Cord

Question 1

What are the 3 functions of the spinal cord

Answer 1

Connect PNS to regions inferior to head with brain, white matter deals with sensory and motor pathways, inner gray matter is a reflex center

Question 2

What are the protective features surrounding the spinal cord

Answer 2

Bone, meninges, and CSF

Question 3

What is the difference in the meninges of the spinal cord compared to the brain

Answer 3

Has epidural space (fat filled space around dura mater)

Question 4

Where is anesthetic inserted in an epidural and why

Answer 4

Into the epidural space so that the dura mater doesn’t have to be punctured

Question 5

What is white matter of the spinal cord

Answer 5

Myelinated and unmyelinated axons create columns go transport sensory info towards brain and motor info away

Question 6

What are the white columns of the spinal cord

Answer 6

Posterior funiculus, anterior funiculus, and lateral funiculus

Question 7

What are the major tracts of the spinal cord

Answer 7

Ascending tracts (sensory interneuron axons) and descending tracts (motor interneuron axons)

Question 8

What is the gray matter of the spinal cord

Answer 8

Neuronal cell bodies, dendrites, and glial cells separated into horns

Question 9

What are the horns of the spinal cord

Answer 9

Ventral (anterior) horn (motor neurons leave here), dorsal (posterior) horn (sensory neurons enter here), and lateral horns (visceral motor neurons/ANS) only found below cervical regions

Question 10

What are the 4 classes of neurons in the PNS

Answer 10

Somatic sensory, visceral sensory, somatic motor, and visceral motor

Question 11

Where are somatic and visceral sensory neurons located in the spinal cord and where do they go

Answer 11

Cell bodies in dorsal root ganglia close to spinal cord, travel from dorsal root to dorsal horns

Question 12

How do somatic motor neurons travel in the spinal cord

Answer 12

Cell bodies in ventral horns exit through ventral root

Question 13

How do visceral motor neurons travel in the spinal cord

Answer 13

Cell bodies in lateral horns exit through ventral root

Question 14

What types of neurons do spinal nerves of the PNS contain

Answer 14

Both sensors and motor neurons

Question 15

What is the reflex arc

Answer 15

Automatic and rapid motor responses that don’t require input from the brain (but info is still sent there to allow for override of reflex)

Question 16

What are the type of reflex arcs

Answer 16

Monosynaptic (axon terminals of sensory neurons synapse directly with motor neuron within spinal cord - e.g. patellar reflex), and polysynaptic reflex (axon terminals of sensory neurons connected via 1+ interneurons to motor neuron)

Question 17

What is the pneumonic to remember which root contains which kind of neurons in the spinal cord

Answer 17

PS (posterior sensory) and AM (anterior motor)