Lab Exercise 17

Question 1

What are the functions of the spinal cord?

Answer 1

carries sensory information to the brain and motor output to nerves, mediates spinal reflexes

Question 2

What do spinal reflexes do?

Answer 2

process sensory input and convey motor output to the spinal nerves

Question 3

What protects the spinal cord?

Answer 3

bony vertebrae, adipose tissue, spinal meninges, cerebrospinal fluid

Question 4

What does adipose tissue do in relation to the spinal cord?

Answer 4

cushions the spinal cord and is found within the space between the vertebrae and the meninges

Question 5

What is the space between the vertebrae and the meninges called?

Answer 5

epidural space

Question 6

What are meninges?

Answer 6

connective tissue membranes that cover the spinal cord and are continuous with the cranial meninges that protect the brain

Question 7

What is the dura mater?

Answer 7

the outer meninx; a tough, single-layered membrane that is deep to the epidural space and superficial to the spider web-like arachnoid mater

Question 8

What is in the pia mater?

Answer 8

the inner meninx that is delicate and hugs the spinal cord

Question 9

What are denticulate ligaments?

Answer 9

lateral extensions of pia mater that fuse with arachnoid mater and secure the spinal cord

Question 10

What is the subarachnoid space?

Answer 10

a space between the pia and arachnoid mater that contains cerebrospinal fluid, which also cushions the spinal cord

Question 11

How many pairs of spinal nerves are attached to the spinal cord?

Answer 11

31 pairs

Question 12

What is the cervical enlargement?

Answer 12

a bulge located at levels C3 or C4 through T1; designates the location of nuclei, for the upper extremities

Question 13

What is the inferior lumbar enlargement?

Answer 13

located at levels T9 through T12 and contains nuclei for the lower extremities

Question 14

What is the conus medullaris?

Answer 14

Where the spinal cord ends inferiorly between vertebral levels L1 and L2

Question 15

What is the cauda equina?

Answer 15

nerve roots (group of axons) arising from the inferior portion of the spinal cord continue inferiorly as a group called the cauda equina

Question 16

What is the filum terminale?

Answer 16

an extension of the pia mater that continues past the conus medullaris and connects the inferior end of the spinal cord to the coccyx

Question 17

What is the anterior median fissure?

Answer 17

a wide, deep groove on the anterior surface of the spinal cord

Question 18

What is the posterior median sulcus?

Answer 18

a narrow groove on the posterior surface

Question 19

What do anterior (ventral) gray horns contain?

Answer 19

somatic motor neuron cell bodies

Question 20

What do lateral gray horns contain?

Answer 20

cell bodies of autonomic motor neurons

Question 21

What do posterior (dorsal) gray horns contain?

Answer 21

neuron cell bodies that receive impulses from sensory neurons

Question 21

What is the gray commissure?

Answer 21

a narrow bridge of gray matter that connects the right and left sides of gray matter in the middle of the spinal cord

Question 22

What is the central canal?

Answer 22

located in the center of the gray commissure and contains cerebrospinal fluid

Question 23

What are the anterior, lateral, and posterior white columns?

Answer 23

columns or funiculi made up of white, myelinated fibers that are either sensory or motor fibers

Question 24

What are spinal nerves formed from?

Answer 24

a posterior (dorsal) root and an anterior (ventral) root

Question 25

What are roots?

Answer 25

collections of axons that are going to and leaving the spinal cord

Question 26

What does the posterior (dorsal) root do?

Answer 26

carries sensory fibers

Question 27

What do the anterior (ventral) root and lateral ventral roots do?

Answer 27

carry motor fibers

Question 28

What is the posterior (dorsal) root ganglion?

Answer 28

a bulge in the posterior root that consists of sensory neuron cell bodies that synapse onto interneuron and/or motor neuron cell bodies in the spinal gray matter