Mod5-Obj1: The spinal cord

Question 1

The spinal cord

Answer 1

Structurally and functionally integrated with the brain

Question 2

The spinal cord is composed of

Answer 2

Interneurons

Question 3

The spinal cord receives and directs…

Answer 3

Incoming sensory information to processing centres in the brain

Question 4

The spinal cord receives and relays…

Answer 4

Motor output from the brain

Question 5

The spinal cord initiates…

Answer 5

Spinal reflexes

Question 6

The vertebral column

Answer 6

The spinal cord is encased within the vertebral canal, formed by alignment of multiple vertebral foramen

Question 7

Spinal cord runs through here

Answer 7

Vertebral foramen

Question 8

Spinal nerves exit here

Answer 8

Intervertebral foramen

Question 9

Gross anatomy of the spinal cord

Answer 9

Approximately 42cm long and 14mm wide

-Extends from foramen magnum to L2 in adults and L4 in infants

Question 10

The spinal cord terminates in a cone shaped structure called the

Answer 10

Conus medullaris

Question 11

Filum terminale

Answer 11

Fibrous connective tissue extending from the conus medullar is to anchor the spinal cord to the coccyx

Question 12

Divided into 31 segments

Answer 12

1.) Cervical (C1-C8)
2.) Thoracic (T2-T12)
3.) Lumbar (L1-L5)
Conus medullaris
4.) Sacral (S1-S5)
5.) Coccygeal (CO1)

Question 13

Lumbar, sacral and coccygeal segments of the spinal cord are

Answer 13

“squeezed” into the conus medullaris

Question 14

Spinal nerves

Answer 14

Short nerves

• Contain both sensory & motor axons
• Connect to the spinal cord at one end and branch to form peripheral nerves at the other

Question 15

Spinal nerves attach to the spinal cord by paired nerve roots

Answer 15

Ventral and dorsal roots

Question 16

Ventral root

Answer 16

Contains the axons of motor neurons (issues motor commands to effector glands and muscles)

Question 17

Dorsal root

Answer 17

Contains the axons of sensory neurons (relays input from receptors to the spinal cord)
-Cell bodies of these sensory neurone lie within the dorsal root ganglion

Question 18

Example of dorsal root (way into spinal cord) and the ventral root (way out)

Answer 18

Sensory receptors in the skin move through peripheral nerves into the dorsal root ganglion, into the cell body and axon of sensory neurons. From the dorsal root interneurons connect to the ventral root, thus the axon of motor neuron, moves through spinal nerves, into the neuromuscular junction

Question 19

Cauda equina

Answer 19

While the spinal cord ends at L2, the lumbar, sacral and coccygeal nerve roots, extend inferiorly to reach the point of spinal nerve exit from the vertebral column
-Conus medullaris, cauda equina, filum terminale

Question 20

The spinal cord is protected by the

Answer 20

1. ) Vertebral column
2. ) Spinal meninges
3. ) Cerebrospinal fluid

Question 21

The spinal meninges

Answer 21

Are continuous with the brain meninges (dura, arachnoid and pia mater)

• Contain CSF within the subarachnoid space
• Provide stability and protection for the spinal cord
• Contain blood vessels that delver oxygen&nutrients to cord tissue

Question 22

The spinal meninges location…

Answer 22

The dura and arachnoid mater extend beyond the end of the spinal cord (at L2) to the level of S2

Question 23

A lumbar puncture (spinal tap)

Answer 23

Involves the insertion of a needle into the subarachnoid space beyond L3 (L4&L5)

• does not damage the spinal cord
• Is used to withdraw CSF for fluid for diagnostic testing or to reduce ICP
• May be used to administer medications

Question 24

The spinal meninges are separated from the vertebral column by an

Answer 24

Epidural space
-Filled with adipose tissue and blood vessels
-Site of anaesthetic injection
Are secured to the spinal cord by denticulate ligaments

Question 25

The meninges hierarchy

Answer 25

• Bone (skull or vertebral column)
• Epidural space (spinal cord only)
• Dura mater
• Subdural space (serous fluid&blood vessels)
• Arachnoid mater
• Subarachnoid space (CSD&blood vessels)
• Pia mater
• nervous tissue

Question 26

The spinal cord consists of gray and white matter (opposite to the brain) and is divided into left and right halves by two grooves:

Answer 26

1. ) Anterior (ventral) median fissure

2. ) Posterior (dorsal) median sulcus