13.2 The Spinal cord

Question 1

What is the name of the protective membrane around the spinal cord

Answer 1

Meninges

Question 2

What are the four regions of the spinal cord

Answer 2

4 regions (cervical, thoracic, lumbar, sacral)

Question 3

State the grooves that divide the spinal cord into left and right.

Answer 3

Posterior median sulcus—posterior side
* Anterior median fissure—deeper, anterior groove

Question 4

What is contained in central canal?

Answer 4

Cerebrospinal fluid

Question 5

Explain the enlargement of the spinal cord

Answer 5

Areas of the spinal cord that supply the limbs have more gray matter and are visibly wider, such as the cervical region which supplies the shoulder and upper limbs, and the lumbosacral region which supplies the pelvis and lower limbs

Question 6

What are the two branches of the spinal nerves?

Answer 6

1. Anterior root (ventral root)—axons of motor
   neurons
2. Posterior root (dorsal root )—axons of sensory neurons

Question 7

Describe the spinal ganglia

Answer 7

It contains cell bodies of sensory neurons that form the posterior root.

Question 8

The spinal nerve divides into

Answer 8

Rami

Question 9

Identify the Rami of the spinal nerves

Answer 9

Posterior ramus supplies skin/muscles of back
* Anterior ramus supplies most of body wall, skin, limbs

Question 10

Identify the specialized membranes surrounding spinal cord

Answer 10

• Dura mater—outermost layer
• Arachnoid mater—middle layer
• Pia mater—innermost layer

Question 11

What is the function of the spinal meninges

Answer 11

protect spinal cord
carry blood supply

Question 12

Describe the dura mater

Answer 12

It is a tough dense collagen fiber that is continuous with the cranial dura mater and fuses with the periosteum of the occipital bone.

Question 13

Describe the spaces in the dura mater

Answer 13

Epidural space
* Between vertebrae and dura mater (superficial to
dura mater)
* Contains loose connective and adipose tissue
– Subdural space = potential space deep to dura mater
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Question 14

Describe the arachnoid mater

Answer 14

it’s in the middle of the meningeal layer and has two components. The arachnoid membrane is web-like with squamous epithelia and the Arachnoid trabeculae is a network of collagen or elastic fibers between the arachnoid membrane.

Question 15

Describe the space in the arachnoid mater

Answer 15

The subarachnoid space contains arachnoid trabeculae, between arachnoid mater and pia mater which is filled with cerebrospinal fluid that carries dissolved gases, nutrients and waste.

Question 16

Describe the pia mater

Answer 16

it is the innermost meningeal layer which is a mesh of collagen and elastic fibers. The blood vessels on the surface of the spinal cord within the subarachnoid space.