4 & 5 SPINAL CORD Flashcards
How many spinal levels are there
31
Describe the external anatomy of the spinal cord
Extends from the foramen magnum to lower border of L1 where cauda equine begins
What is the section of the spinal cord called before it gives off the cauda equina
Conus medularis
What anchors the spinal cord down
The filum terminale
Describe the layers of the spinal cord and the spaces the create
Pia mater Subarachnoid space (CSF) Arachnoid mater Virtual space Dura mater Epidural space (fat, arteries, veins)
What is the layer called that surrounds the dorsal root ganglion
The epineurium
List organisation of nerve pathway from spinal cord
Spinal cord, rootlets, roots, root ganglion, mixed nerve, posterior and anterior ramus and ramus communicans
Describe the function of the posterior and anterior ramus
Mixed nerve bundles which supply the posterior and anterior aspects of the body respectively
Describe the function of the ramus communicans
Supplies information to the sympathetic chain.
Name the sulcus’s in the white matter
Median sulcus. Dorsal intermediate sulcus. Dorsolateral sulcus. Ventral lateral sulcus
Describe the functional anatomy of the dorsal funiculus
Where detection of discriminative sensation occurs. There are two sub divisions; the cuneate (lateral) fasiculi and the gracile (medal) fasiculi. Cuneate present from around T6 pathway for upper limb, hand most posterior. Gracile lower limb. Toes most posterior
Describe the lateral funiculus
Where upper motor neurons from the primary motor cortex travel before synapsing with lower motor neurons in lamina 8 & 9 at the spinal level which they exit.
Describe the ventral funiculus
Where pain and temperature neurons travel
What travels through the dorsolateral tract of lissauer
Axons of non-discriminative neurons en route to lamina 1 and 2
What occurs in lamina 1 and 2
First order non-discriminative sensation neurons synapse with second order neurons which then decussate to the contralateral ventral funiculus. Lamina 1 fibres don’t have opioid receptors so hard to target. Some granular interneurons also connect with motor pathways in lamina 8 & 9 to allow for the withdrawl/ polysynaptic reflex.
