Anatomy of the Spinal Cord

Question 1

Answer 1

Vertebral Canal

• The spinal canal is the space in the vertebral column formed by the vertebrae through which the spinal cord passes

Question 2

Answer 2

Filum terminale

• A fibrous extension of the pia mater, extends even farther into the coccygeal canal to attach to the posterior coccyx
• Proceeds downward from the apex of the conus medullaris

Question 3

Answer 3

Spinal cord conus medullaris

• The cone shaped end of the spinal cord
• Ends at the level of L1 or L2

Question 4

Answer 4

Foramen Magnum

• Level of the origin of the spinal cord

Question 5

Answer 5

Denticulate ligaments

• Saw-toothed shelves of the pia mater
• Secures the spinal cord to the bony wall of the vertebral column all along its length

Question 6

Level of the termination of the spinal cord

Answer 6

• The spinal cord ends at the level L1 or L2

Question 7

Length of the spinal cord

Answer 7

• Approximately a meter long
• Ends at L1 or L2

Question 8

Answer 8

Meninges

• The three membranes (dura mater, arachoid layer, and pia mater) that lines the skull and the vertebral spinal cord
• Encloses the bone and spinal cord

Question 9

Answer 9

Subarachnoid Space

• Space between the arachnoid layer and the pia mater that has threadlike projections and contains the spinal fluid

Question 10

Answer 10

Subdural space

• Space that is between the dura mater and the arachnoid layer

Question 11

Answer 11

Epidural space

• Space between the dura mater and the bones of the vertebral canal

Question 12

Answer 12

Cerebrospinal Fluid (CSF)

• A liquid that fills the ventricles of the brain, the central canal of the spinal cord, and the space between the CNS (brain and spinal cord), and dura mater
• “Cushions”/protects the brain and spinal cord

Question 13

Answer 13

Dura Mater

• “Tough mother”
• The outermost, leathery double membraine layer of the meninges

Question 14

Answer 14

Arachnoid Layer

• Delicate, weblike middle layer of the meninges

Question 15

Answer 15

Pia Mater

• Delicate inner layer of the meninges which is highly vascular

Question 16

Number of spinal nerves

Answer 16

31 pairs

Question 17

Answer 17

Cervical Enlargment

• A thickening in the spinal cord that supplies nerves to the upper limbs
• Corresponds with the attachments of the large nerves which supply the the upper limbs
• Extends from C3 to T2

Question 18

Answer 18

Lumbar enlargment

• A widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs
• From L2 to S3

Question 19

Answer 19

Cauda equina

• “Horse’s tail”
• Spinal nerves that extend down the vertebral canal past the level of the spinal cord (beyong L1 or L2)

Question 20

Location of where a lumbar (spinal) tap would be made

Answer 20

L4/L5

Question 21

Location of where a saddle block/epidural would be made

Answer 21

L3-L5

Question 22

Answer 22

Gray Matter

• The darker tissue of the spinal cord
• A zone or layer of tissue in the central nervous system where the neuron cell bodies, dendrites, and synapses are found
• The core “butterfly” of the spinal cord

Question 23

Characteristiscs of gray matter

Answer 23

1. Butterfly shape
2. Made up of neurons
3. Not myelinated

Question 24

Generalization of the “butterfly”

Answer 24

• The central “butterfly” is gray matter
• Gray matter contrains cell bodies, dendrites, and unmyelinated cells

Question 25

Answer 25

**Posterior Dorsal Horns** * Recieves sensory fivers from the spinal nerves * The two dorsal projections of the gray matter recieves sensory fivers from the spinal cord

Question 26

Answer 26

**Anterior (ventral) horns** * Contains the cell bodies of lower motor neurons * The tips of the ventral horns are boarder and less tapered than those of the dorsal horns

Question 27

Answer 27

**Gray Commissure** * The central area of gray matter connecting the two vertical regions

Question 28

Answer 28

**Central canal** * The gray commissure surrounds the central canal of the spinal cord * The central canal is a cerebrospinal fluid filled spaced that runs longitudinally through the entire length of the spinal cord

Question 29

Answer 29

**Arachnoid Layer** * Delicate, weblike middle layer of the meninges

Question 30

Answer 30

**Pia Mater** * Delicate inner layer of the meninges which is highly vascular

Question 31

Answer 31

**Dura Mater** * "Tough mother" * The outermost, leathery double membraine layer of the meninges

Question 32

Answer 32

**Epidural space** * Space between the dura mater and the bones of the vertebral canal

Question 33

Answer 33

**Subarachnoid Space** * Space between the arachnoid layer and the pia mater that has threadlike projections and contains the spinal fluid

Question 34

Answer 34

**Subdural space** ## Footnote Space that is between the dura mater and the arachnoid layer

Question 35

Answer 35

**Dorsal (Posterior) Root** * The dorsal horns contain interneurons and sensory fibers that enter the cord from the body periphery via the dorsal root

Question 36

Answer 36

**Dorsal (posterior) root ganglion** * Sensory fibers * Lacks motor neurons * The cell bodies of these neurons are found in the enlarged are of the dorsal root (called the dorsal root ganglion)

Question 37

**Tracts**

Answer 37

**Tracts** * Collections of axons in CNS

Question 38

**Nerves**

Answer 38

**Nerves** * Collections of axons in PNS

Question 39

**Ganglia**

Answer 39

**Ganglia** * Collections of neuron cell bodies in PNS

Question 40

**Nucleus (nuclei)**

Answer 40

**Nucleus (nuclei)** * Collections of neuron cell bodies in CNS

Question 41

Answer 41

**Dorsal Root** * The dorsal root is an afferent root, meaning it carries neural signals from the limbs and organs back to the spinal cord and brain * Afferent = sensory

Question 42

Answer 42

**Dorsal Root Ganglion**

Question 43

Answer 43

**Spinal Cord**

Question 44

Answer 44

**Ventral Root**

Question 45

Answer 45

**White Matter**

Question 46

Answer 46

**Gray Matter**

Question 47

Answer 47

**Spinal Ganglion**