Anatomy of the spinal cord

Question 1

Spinal cord location

Answer 1

Spinal cavity within the vertebrae
starts at the foramen magnum
ends at the inferior border of the 1st lumbar vertebra

Question 2

Spinal cord surroundings

Answer 2

sits within a fibrous sac made of meninges, inside the spinal cavity

Question 3

Non-neural structures associated with the spinal cord (3)

Answer 3

• meningeal sac filled with cerebrospinal fluid (CSF)
• conus medularis, tapered cone-like end
• filum terminale

Question 4

Meningeal sac

Answer 4

• what the spinal cord is extended in
• filled with CSF
• provides a liquid cushion around the spinal cord to protect it from injury

Question 5

Conus medularis

Answer 5

tapered cone-like end of the spinal cord

Question 6

Filum terminale

Answer 6

• extends from the conus medularis to the end of the spinal cavity
• anchors the spinal cord
• made of fibrous, non-neural tissue

Question 7

8 pairs of ______ spinal nerves

Answer 7

cervical

Question 8

12 pairs of _____ spinal nerves

Answer 8

throacic

Question 9

5 pairs of _____ spinal nerves (upper)

Answer 9

lumbar

Question 10

5 pairs of _____ spinal nerves (lower)

Answer 10

sacral

Question 11

1 pair of _____ spinal nerves

Answer 11

coccygeal

Question 12

Cauda Equina

Answer 12

large collection of nerves inferior to the end of the spinal cord. these nerves have to grow more to exit the spinal cord at the right vertebra

Question 13

Spinal nerves are named by the vertebra they exit below, with the one exception being…

Answer 13

the first cervical spinal nerve exits between the skull and the first cervical vertebra. there are 8 cervical spinal nerves but only 7 cervical vertebrae

Question 14

2 spinal cord indentations

Answer 14

• posterior median sulcus

- anterior median fissure

Question 15

‘H’ shaped mass is made of

Answer 15

grey matter (cell bodies)

Question 16

Surrounding the grey matter is

Answer 16

white matter (bundle of axons that run the length of the spinal cord)

Question 17

CNS features of the spinal cord

Answer 17

• grey matter
• white matter
• dorsal horn
• dorsal column
• ventral horn
• lateral horn
• lateral column

Question 18

PNS features of the spinal cord

Answer 18

• nerve roots (axons)
• ganglions (cell bodies)
• dorsal nerve roots
• dorsal root ganglions
• ventral nerve rootS

Question 19

Information flow:

Dorsal side of spinal cord

Answer 19

sensory (afferent)

Question 20

Information flow:

Dorsal nerve roots

Answer 20

axons conduct information from PNS into CNS

Question 21

Information flow:

Ventral side of spinal cord

Answer 21

motor (efferent)

Question 22

Information flow:

Ventral nerve root

Answer 22

axons conduct information from CNS into PNS

Question 23

Flow of afferent information:

into the spinal cord (3 steps)

Answer 23

• cell bodies of sensory neurons are in dorsal root ganglion
• input zone in body associates with receptors for sensory stimulus
• output zone enters the spinal cord through dorsal roots

Question 24

Spinal nerve branches:

Dorsal ramus

Answer 24

carries efferent information to the back and afferent information from the back

Question 25

Spinal nerve branches:

Ventral ramus

Answer 25

carries efferent information to the front and afferent information from the front

Question 26

Spinal nerve branches:

Rami communicans

Answer 26

sympathetic, only at T1 - L2

only carries information to and from the sympathetic ganglion

Question 27

Structure of a peripheral nerve (6 features)

Answer 27

• individual axons may be myelinated (shown) or unmyelinated (not shown)
• axons are covered with endoneurium
• endoneurium-covered axons are bundled together to form a fascicle
• fascicles are covered in perineurium
• fascicles bundle with each other and with blood vessels to form a nerve
• nerves are covered by epineurium