Spinal Cord Flashcards
What protects the spinal cord?
Skin, epaxial muscles, vertebrae, meninges. It is very well protected.
List the meninges from outer to inner layers.
- Dura mater 2. Arachnoid 3. Pia mater
What is the delicate layer with spider web-like filaments?
Arachnoid layer
Where is the CSF found?
In the subarachnoid space.
What is the subdural space?
A vascular layer that is associated with the dura.
Which of the meninges is adhered to the spinal cord and brain?
Pia mater
Which layer is fused with the periosteum in the cranial cavity?
Dura mater
____ form an envelope that completely encloses the brain and spinal cord.
The meninges
Where is the epidural space? What fills this space?
Between the vertebrae and dura mater. Contains fat and fluid.
What are denticulate ligaments?
Connections from the dura to spinal cord, helps with stabilization.
What is a complete dorsal laminectomy?
A procedure where the laminae of the vertebral column are cut and removed to expose the spinal cord.
What is a hemilaminectomy?
A procedure where one side of the vertebral column is cut at the laminae to expose the spinal cord.
How does the length of the spinal cord compare to the length of the vertebral column. What is the consequence of that?
The spinal cord is shorter. Spinal nerves start coming off straight but become more parallel to the spinal cord dorsally.
What are the thickenings of the spinal cord called?
Brachial plexus and lumbosacral plexus.
What is the structure at the end of the spinal cord that is the shape of a cone?
Medullary cone.
What is the collection of spinal nerves at the end of the spinal cord called?
Cauda equina.
Where does the spinal cord end?
Around the ilium.
Where is CSF fluid collected or anesthetic administered in the caudal part of the spinal cord?
Lumbosacral interarcurate space.
Where is the lumbosacral interarcurate space?
Depends on species - cranial to the sacrum.
Where are epidural anesthetics administered?
Very caudally, more caudal than the lumbosacral interarcurate space.
What is the filum terminale?
A small string-like structure coming off the end of the spinal cord. Terminates on the caudal vertebrae. Most caudal anchor point.
How many cranial spinal nerves are there?
8 - named by the vertebrae caudal to them. C8 is caudal to C7 vertebra and cranial to T1.
How many thoracic nerves are there?
Same # as vertebrae
How many lumbar nerves are there?
Same # as vertebrae
How many sacral nerves are there?
Same # as vertebrae
How many caudal vertebrae are there?
Same # as vertebrae
Where are neuronal cell bodies found in the spinal cord?
Grey matter - Inside of spinal cord.
What are ganglia?
Structures outside of the spinal cord that contain neuronal cell bodies.
Central grey matter changes based on….
Location in the spinal cord, larger if there are more neuronal cell bodies.
What do the two branches of a spinal nerve innervate?
Dorsal rami - epaxial muscles. Ventral rami - hypaxial muscles and other structures.
Which ramus of a spinal nerve is bigger?
Ventral ramus - innervates more.
Where is the spinal nerve formed? What happens immediately after its formation.
Formed after ganglia, splits into two rami.
The dorsal root contains…
Afferent neurons
The ventral root contains…
efferent neurons.
What is the direction of axons in the dorsal root?
Axons enter spinal cord.
Where are the dendrites of the ventral root?
In the ventral horn.
Do dorsal root or ventral root neurons have long dendrites?
Dorsal root.
Where are the cell bodies of ventral root neurons.
Ventral horn
Why are spinal nerves called mixed nerves?
There are 4 different pathways in the nerve (somatic afferent, somatic efferent, visceral afferent, visceral efferent).
What are funiculi?
Regions of the white matter. Composed of ascending and descending nerve fibers that are grouped to form tracts.
Dorsal funiculus is mainly composed of…
ascending tracts (towards the brain)
Lateral funiculus contains…
Ascending (laterally) and ascending/descending (medially) tracts
Ventral funiculus contains…
Both ascending and descending tracts
Spinal nerves exit through…
intervertebral foramen.
Spinal nerves innervate _____ while plexus nerves innervate _____.
Spinal = trunk elements. Plexus = limbs.
The intrinsic limb muscles are innervated by…
the ventral ramus of spinal nerves.
The arterial supply of the spinal column includes…
A ventral spinal artery and 2 dorsolateral arteries.
The venous supply of the spinal cord involves…
a plexus.
Inside the spinal cord, the venous system is called _____. As it exits, it is called _____.
Inside = plexus. Outside = intervertebral vein.
