Spinal Cord and Meninges

Question 1

What nervous system is the spinal cord a part of?

Answer 1

The central nervous system

Question 2

What is the role of the spinal cord in the central nervous system?

Answer 2

Major reflex centre and conduction pathway between the brain and the body

Question 3

Where does the adult spinal cord begin and end?

Answer 3

Begins: Medulla oblongata
Ends: L1/L2

Question 4

Where does the spinal cord end in children?

Answer 4

L3

Question 5

Compare the spinal cord and vertebral canal in the feotus

Answer 5

Almost equal length

Question 6

What do remaining spinal nerves in adults form?

Answer 6

Vertebral canal grows and cord ends at L1-L2 level in adults

Remaining spinal nerves form cauda equina

Question 7

What is the conus medullarise?

Answer 7

Conical inferior end of spinal cord

Question 8

What is the cauda equina?

Answer 8

Bundle of spinal nerve roots that resembles a horse tail

Question 9

What is the filum terminale?

Answer 9

Continuation of pia matter (internum) that extends from the terminal end of the spinal cord to the tailbone.

Question 10

How can you histologically differentiate grey matter?

Answer 10

H shaped - cell bodies are located here

Question 11

What is white matter made up of?

Answer 11

Axons

Question 12

What are nissl bodies made up from?

Answer 12

Rough endoplasmic reticulum in the cell bodies

Question 13

Where do spinal nerves exit the vertebral canal?

Answer 13

Through intervertebral foramen

Question 14

What do ventral rami form?

Answer 14

Nerve plexuses that supply the brachial plexus and lumbosacral plexus

Question 15

What does the brachial plexus supply?

Answer 15

Upper limb

Question 16

Where does the brachial plexus originate from?

Answer 16

The ventral rami of the C5-T1

Question 17

What does the lumbosacral plexus supply?

Answer 17

Lower limb

Question 18

Where does the lumbosacral plexus originate from?

Answer 18

L1, L2, L3, L4

Question 19

What does the ventral/anterior rami supply?

Answer 19

Anterolateral part of the trunks and limb

Mixed fibres

Question 20

What does the dorsal/posterior rami supply?

Answer 20

The facet joints, deep muscles of the back and the skin of the back.

Question 21

What type of fibres are in a spinal nerve?

Answer 21

Sensory
Motor
Sympathetic

Question 22

What are the meninges?

Answer 22

Three layers of membranes known as meninges protect the brain and spinal cord.

Question 23

What are the meninges made from?

Answer 23

Fibrous tissue

Question 24

What are the three layers of the meninges?

Answer 24

Top, tough layer - dura matter
Middle - archanoid matter
Bottom - pia matter

Question 25

Where can cerebrospinal fluid (CBS) be found?

Answer 25

Between the arachnoid and pia matter subarachnoid space

Question 26

What is the space between the dura matter and vertebral body?

Answer 26

Epidural space - contains fat, the dural sac, spinal nerves, blood vessels and connective tissue

Question 27

What connects the arachnoid and pia matter?

Answer 27

Arachnoid trebeculae - delicate strands of connective tissue

Question 28

Discuss the vascularation of the meninges

Answer 28

Dura mater - vascular Archnoid mater - avascular Pia mater - very vascular, has blood vessels that supplies spinal cord

Question 29

What is the ligament that comes off the pia matter?

Answer 29

Denticulate ligament

Question 30

What is the role of the denticulate ligament?

Answer 30

Stabilize the spinal cord within the vertebral canal/supports the spinal cord in the subarachnoid space

Question 31

Where is the subarachnoid space?

Answer 31

The subarachnoid space is the interval between the arachnoid mater and the pia mater.

Question 32

What is the role of the filium terminali?

Answer 32

The filum terminale helps to anchor the spinal cord in place.

Question 33

What is the dural sac?

Answer 33

Membranous sheath of dura mater that surrounds the spinal cord and the cauda equina.

Question 34

What is the dural sac filled with?

Answer 34

Cerebrospinal fluid and all the cauda equina nerve roots.

Question 35

Where does the dural sac end?

Answer 35

Terminates at S2 vertebral level

Question 36

What is the dural sac attached to?

Answer 36

The tip of the coccyx by filum terminale externum

Question 37

What are the two outflows of the autonomic nervous system?

Answer 37

Sympathetic outflow Parasympathetic outflow

Question 38

What is another name for sympathetic outflow?

Answer 38

Thoracocolumbar outflow

Question 39

What are the root values for thoracolumbar outflow?

Answer 39

T1-L2

Question 40

Where are the cell bodies of the sympathetic outflow located?

Answer 40

Lateral horn of grey matter

Question 41

What is another name for parasympathetic outflow?

Answer 41

Craniosacral outflow Crania outflow from brain Sacral outflow from pelvic splanchnic nerve (S2-S4)

Question 42

What happens if there is a deficiency of blood supply to the spinal cord?

Answer 42

Ischemia, muscle weakness and paralysis

Question 43

Discuss the venous drainage of the spinal cord

Answer 43

Drains into the internal vertebral venous plexuses. Will then drain into cerebral dural venous sinuses

Question 44

What is the arterial supply to the spinal cord?

Answer 44

Via three longitudinal arteries – the anterior spinal artery and the paired posterior spinal arteries.

Question 45

What is the anterior spinal artery formed from?

Answer 45

Formed from branches of the vertebral arteries. They travel in the anterior median fissure.

Question 46

What do the paired posterior spinal arteries originate from and what do they do?

Answer 46

Originate from the vertebral artery or the posteroinferior cerebellar artery. They anastamose with one another in the pia mater.

Question 47

What are venous plexuses of the spinal cord formed by?

Answer 47

By spinal veins along the vertebral column, both inside and outside the vertebral canal.

Question 48

What are the names of the two venous plexuses of the vertebral column?

Answer 48

Internal vertebral venous plexus (or the epidural venous plexus) External vertebral venous plexuses

Question 49

How do the venous plexuses communicate?

Answer 49

Through the intervertebral foramina

Question 50

How can infection/cancer impact the spinal cord?

Answer 50

Can spread to vertebrae/spinal cord/brain/ skull from other parts of the body

Question 51

What types of injuries can the spinal cord endure?

Answer 51

Blunt trauma Penetrating injuries

Question 52

What can cause compression of the spinal cord?

Answer 52

Disc prolapse or bone mestastasis from a primary cancer/stenosis of the vertebral canal

Question 53

What can compression of the spinal cord lead to?

Answer 53

Complete or partial loss of motor function and sensation (including distruption of autonomic function) and pain

Question 54

Where does lumbar puncture occur in adults?

Answer 54

The subarachnoid L4-5 interspace

Question 55

Where does lumbar puncture occur in children?

Answer 55

At or below the L4 level. The L4 landmark in older children - the line of the top of the iliac crests.

Question 56

When are lumbar punctures needed?

Answer 56

Testing of the cerebrospinal fluid - looking for infectious diseases of the brain and spinal cord, including meningitis and encephalitis.

Question 57

What is the lumbar location for epidural anesthesia?

Answer 57

Outside of the dura matter - needle does not penetrate