Lec 14 Nervous System 2 - Spinal Cord

Question 1

what is the conus medullaris?

Answer 1

a cone shaped terminal part of spinal cord. L1 - L2

Question 2

what is the cauda equine?

Answer 2

“Horse’s Tail”

composed of nerve fibers or axons

Question 3

what is the filum terminale?

Answer 3

from tip of conus medullaris; a connective tissue that extends to the sacrum.

composed of pia mater

Question 4

define meninges

Answer 4

connective tissue covering the brain and spinal cord

Question 5

what are the different layers of meninges?

Answer 5

dura mater
arachnoid
pia mater

Question 6

what is the dura mater?

Answer 6

the outermost layer

Question 7

what is the arachnoid?

Answer 7

a flimsy, very thin layer.

Question 8

what is the pia mater?

Answer 8

connective tissue that touches spinal cord and brain

Question 9

where is the cerebrospinal fluid located? what is it produced by?

Answer 9

located in subarachnoid space, produced in ventricles of the brain aka choroid plexus

Question 10

where is the subarachnoid space located?

Answer 10

deep to arachnoid, between arachnoid and pia mater

Question 11

where is the epidural space located?

Answer 11

external to dura mater

Question 12

where is subdural space located, what does it contain?

Answer 12

internal to dura mater, nothing is found here.

Question 13

at which vertebral level could the spinal tap procedure be safely done?

Answer 13

L3-L4 or L4-L5 because the spinal cord ends at L1 - L2

Question 14

what anatomical landmark would you use to located the correct level to do a spinal tap?

Answer 14

iliac crest

Question 15

List in order the structures your needle would have to pierce to reach the subarachnoid space.

Answer 15

1. skin
2. subcutaneous tissue
3. ligaments
4. dura mater
5. arachnoid mater - CSF fluid

Question 16

what is the white matter of the spinal cord made of?

Answer 16

composed of fibers

CNS

Question 17

what does the gray matter of the spinal cord contain?

Answer 17

cell bodies of neurons (ventral horns)

Question 18

what does the dorsal root contain

Answer 18

sensory nerve fibers

Question 19

what does the dorsal root ganglion contain

Answer 19

sensory cell fibers

Question 20

what does the ventral root contain

Answer 20

motor fibers

Question 21

at each segment we find a pair of nerves. what are components of a spinal nerve?

Answer 21

both ventral ramus and dorsal ramus

Question 22

how many synapses are necessary in a withdrawal reflex?

Answer 22

2

Question 23

what are components of a withdrawal reflex?

Answer 23

1. receptor
2. sensory neuron
3. interneuron
4. motor neuron
5. effector (muscle)

Question 24

how many synapses are necessary for a stretch reflex arc?

Answer 24

1

Question 25

what are components of a stretch reflex arc?

Answer 25

1. receptor
2. sensory neuron
3. motor neuron
4. effector (muscle)