Spine Revised Flashcards
Where does the spinal cord begin?
Occipital bone of the skull
Where does the spinal cord end?
L1/L2
(IV disc between the two)
What does the spinal cord form at it’s distal end?
Conus medullaris
What is the fibrous extension of the conus medullaris?
Filum terminale
Which two regions of the spine are enlarged?
Cervical and lumbar
Why is their enlargement in the cervical and lumbar regions of the spine?
For limb innervation
Cervical enlargement for innervation of upper limbs
Lumbar enlargement for innervation of the lower limbs.
Which level does the spinal cord terminate in a child?
Upper border of L3
Which spinal nerves form the cauda equina?
L2-L5
From which spinal structure does the cauda equina emerge from?
Conus medullaris
Where does the filum terminale attach inferiorly?
Coccyx
What is the function of the filum terminale?
Anchors inferior ends of the spinal cord and dural sac.
What makes up the grey matter of the spinal cord?
Cell bodies
What makes up the white matter of the spinal cord?
Nerve fibres
What type of nerve impulse is associated with anterior horn cells?
Motor
Which type of nerve impulse is associated with posterior horn cells?
Sensory
Which type of nerve impulse is associated with lateral horn cells?
Autonomic
What is the function of spinal meninges?
Protect and cushion the spinal cord
Name the three layers of the meninges, starting with the most external.
Dura mater
Arachnoid mater
Pia mater
Which level does the dural sac terminate in adults?
S2
In newborns, which level does the dura mater end at?
S3
In newborns, where does the conus medullarus end at?
L3
What is between pia mater and arachnoid mater?
Subarachnoid space
What is found in the subarachnoid space?
Cerebrospinal fluid
What is the space between the dura mater and vertebral bones?
Epidural space
What is inflammation of the meninges known as?
Meningitus
What can happen in those with meningitis?
Neurological damage or death
Which two layers is the subdural space found in between?
Dura mata
Arachnoid mata
Where does the blood supply for the spinal cord come from?
Branches from the aorta
What drains the spinal cord and vertebrae?
Vertebral venous plexus
Plexus=?
Network
Where would you find the vertebral venous plexus?
Fatty tissue in the episudral space
Do the veins in the vertebral venous plexus have valves?
No
What can the venous plexus provide a route for?
The metastasis of cancer cells
What are nerves emerging from the spinal cord called?
Spinal nerves
Which signals does a spinal nerve carry?
Spinal nerves are mixed nerves so carry motor, sensory and autonomic signals.
Which fibres allow for voluntary movement?
Somatic fibres
Which fibres allow for involuntary movement?
Autonomic fibres
Give examples of involuntary structures.
Glands
Organs
Involuntary muscles e.g. cardiac
Where do sympathetic nerve fibres arise from?
Lateral horn cells
Where are lateral horn cells located?
T1-L2
Where in the spinal cord is the origin for somatic fibres?
Anterior horn
Where in the spinal cord is the origin for autonomic fibres?
Lateral horn
How many ganglia are present in the autonomic pathway?
2
What is another term for sympathetic chain?
Paravertebral ganglia
What do white rami communicants do?
Carry sympathetic fibres from the spinal nerve to the sympathetic chain ganglion.
What do grey rami communicants do?
Carry sympathetic fires from the paravertebral ganglia/sympathetic chain back to the ventral rami of spinal nerve.
Which plexus supplies the upper limb?
Brachial plexus
Which plexus supplies the lower limbs?
Lumbosacral plexus
Are white rami communicants myelinated or unmyelinated?
Myelinated
Are grey rami communicants myelinated or unmyelinated?
Unmyelinated
What is the sympathetic trunk composed of?
Interconnected ganglia
Where do sympathetic fibres arise from the spinal cord?
T1-L2
Describe the three ways sympathetic nerve fibres can supply structures out with T1-L2.
- Synapse in chain ganglia at the same spinal level before exiting the chain.
- Ascend/descend within the sympathetic chain before synapsing in a different ganglion to the one it lies next to.
- Run through the chain without synapsing and synapse instead in a prevertebral ganglion in the abdomen
When would be a common example of a sympathetic fibre synapsing in the chain ganglia at the same spinal level?
When suppling the skin
What are splanchnic nerves?
Nerves which arise from within the sympathetic thoracic trunk to innervate the abdomen
How can parasympathetic nerves be carried?
By some cranial nerves
Spinal nerves
Give an example of a cranial nerve which can carry parasympathetic fibres.
Vagus nerve
Which spinal nerves can carry parasympathetic fibres?
S2-4
Give some examples of large autonomic nerve plexuses.
Cardiac (in thorax)
Pulmonary
Coeliac (in abdomen)
Superior hypogastric (abdomen)
Inferior hypogastric (pelvis)
How do upper and lower imbs receive theeir autonomic supply?
Sympathetic nerves
Do parasympathetic nerves travel or supply to any limbs?
No
