GT Spinal Cord

To supply the spinal cord, the anterior and posterior spinal arteries will branch from ..

The vertebral artery (which branches from the subclavian artery)

Where does the spinal cord begin and end

Begins as extension of medulla oblongata (brainstem), runs through the vertebral canal, from foramen magnum (skull) to approximately L2

Why is the spinal cord enlarged at the cervical and lumbar regions

Due to the brachial plexus (cervical)

Due to lumbrosacral plexus (lumbar)

What is the name for the tapering end of the spinal cord at ~L1-L2, L3

Conus medullaris

(This varies between L1 and L3)

How are nerve roots after L2 able to serve their effectors (target tissues)

Via the cauda equina (~L2-coccygeal nerve roots)

(Compression of or injury to the cauda equina is a medical emergency—hallmark is loss of bladder and bowel function)

What are your spinal meninges and what is their general function (as a whole)

Dura mater

Arachnoid mater

Pia mater

They collectively protect the spinal cord (and brain)

Which meningeal layer is the tough, fibrous outer layer

Dura mater (durable) to L2

Dura is the fibrous protective layer with high density of sensory neurons

What is the web-like, avascular middle meninge

Arachnoid mater

What structure falls between the bone (vertebrae or skull) and the dura mater that primarily contains fat?

Epidural space

Which space falls between the dura mater and the arachnoid layer that only truly appears if there is bleeding

Subdural space

This space only truly exists if blood creates it — we do not really want blood to create anything

Which meningeal layer houses the blood vessels and is the innermost layer, sitting directly on the spinal cord

Pia mater

What structure will help support the pia mater to other meningeal layers?

Denticulate ligaments

Which space will lie in between the arachnoid and the pia maters; houses the cerebrospinal fluid that helps protect the spinal cord

Subarachnoid space

What is the enlargement due to increased CSF

Cistern (lumbar cistern is a great place to find a lot of CSF if doing a lumbar puncture); L3-L5 approximately

What is the primary blood supply for the spinal cord

2 posterior spinal arteries

1 anterior spinal artery

All come from the vertebral artery and segmental branches regionally