The Spinal Cord Flashcards
(44 cards)
What forms the spinal canal ?
It is formed by the vertebral foramen of vertebral bodies, with reinforcement at the walls through vertebral discs and anterior and inferior longitudinal ligaments.
What contains the spinal canal ?
- Spinal cord
- meninges
- blood vessels
- spinal nerves roots
- fatty and connective tissues
What are the 3 main (and broad) functions of the spinal cord ?
- receives much of the sensory information about the environment
- carries all the informations that supply the voluntary muscles
- conduit for the longitudinal flow to and from the brain
Where are the two enlargements of the SC located ?
Cervical level : motor supply for upper limbs
Lumbrosacral level : motor supply for lower limbs
What is the name of the tip of the SC ?
The medullary cone, located between T12 and L1
What is the name of the SC from L2 to S5?
The Cauda equina
What is the name of the very end of the SC? What is it made of ?
The terminal filum which becomes part of the coccygeal ligament. It is a thickening of the pia matter that enchors the SC to sacrum.
List the meninges of the SC
- dura matter
- arachnoid matter
- pia matter
Describe the dura mater
Spreads from the foramen magnum to filium terminale. It is surrounded by epidural space (epidural anesthesia), areaolar connective tissue, fat and blood vessels.
Describe the main features of the arachnoid mater
Part of the meninges
Subarachnoid space is filled with CSF
There is a large lumbar cistern of subarachnoid space filled with CSF around the conus medullaris and cauda equina (target place for lumbar punctures/ spinal tap)
List the main blood supplies of the spinal cord
- single anterior spinal artery
- paired posterior spinal arteries
- anterior radicular arteries
- posterior radicular arteries
- arterial vasocroma (anastomose between spinal arteries)
What brain structures are irrigated by the paired posterior spinal arteries ?
Upper part of the spinal cord
Brainstem
Cerebellum
Posterior part of the brain
From where do the pared posterior spinal arteries emerge and lead to ?
They emerge from the first part of subclavian artery
They connect into basilar artery
What is irrigated by the anterior spinal artery ?
- anterior gray columns
- lateral gray columns
- central gray matter
- anterior funiculus
- lateral funiculus
- anterior portion of the posterior gray matter
What is irrigated by the posterior spinal arteries ?
- posterior portion of the posterior gray matter
- posterior funiculus
What is irrigated by radicular arteries ?
- the entire length of the spinal cord
- spinal nerves roots
- anterior spinal artery
- posterior spinal arteries
What is irrigated by the arterial vasocroma ?
Pia mater of spinal meninges
What are the components of the spinal cord ?
- white matter
- gray matter with central canal
- dorsal horn and ventral horn which merge to form spinal nerves
What is the white matter in the spinal cord ?
A collection of myelinated nerve fibers that carry signal up and down to and from the brain.
It is composed of 3 paris of funiculi (2X dorsal, 2X lateral, 2X ventral). Each funiculus is filled with named tracks (fasciculi = fibers with a similar origin, destination and function).
What is a first order neuron ?
A first order neuron carries signals from the periphery to the spinal cord.
What is a second order neuron ?
A second order neuron carries signals from the spinal cord to the thalamus
What is a third order neuron
A third order neuron carries signal from the thalamus to the primary sensory cortex
What is the function of ascending pathways ?
Ascending pathways transport sensory information related to touch in afferent pathways from the body to the brain. Touch includes : pain, thermal changes, crude and light touch, two points discrimination, vibration, proprioception.
List the known ascending tracts
Dorsal column medial lemniscus :
- gracile fasciculus
- cuneate fasciculus
Dorsal spinocerebellar tract
Ventral spinocerebellar tract
Antero lateral system:
- spinothalamic
- spinoreticular
