Gross Neuro Anatomy Flashcards
How many pairs of spinal nerves are there?
31 pairs
- 8 cervical
- 12 Thoracic
- 5 lumbar
- 5 sacral
- 1 cocygeal
Where are spinal nerves found?
The intervertebral foramina
What is a dermatome?
An area of skin supplied with sensory innervation from a single spinal nerve
What is a Myotome?
The skeletal muscles supplied with motor innervation from a single spinal nerve
Can be deep to the dermatome of the same spinal nerve but not always
Which of the following dermatomes is most likely affected by shingles in this image?
- T3
- T6
- T9
- T12
T6
What is a nerve plexus and give some examples
The intermingled anterior rami from a number of adjacent spinal nerves
- Cervical Plexus- C1-C4, posterior scalp, neck and diaphragm
- Brachial Plexus- C5-T1, upper limb
- Lumbar Plexus- L1-L4, lower limb
- Sacral Plexus- L5-S4, lower limb, gluteal region and perineum
What is the name given the the collection of nerve cell bodies in both the CNS and the PNS?
CNS= nucleus
PNS= ganglion
What is responsible for myelin production in both the CNS and PNS?
CNS= oligodendroctes
PNS= Schwann cells
What type of neuron is this and what modality does it carry?
Multipolar
Motor (efferent)- impulse moves towards the body wall, body cavity or organ
What type of neuron is shown and what modality is it?
Unipolar
Sensory (afferent)- the impulse moves towards the brain
Define a nerve?
A collection of axons surrounded by connective tissue and blood vessels
What type of innervation has a Thoracolumber outflow?
Sympathetic
T1-L2 have lateral horns
What outflow is the parasympathetic described as having?
Craniosacral outflow
CNs III, VII, IX, X
Sacral nerves 2,3,4
What are the groups of intrinsic back muscles?
Erector Spinae (superficial)
Transversospinalis (deep)
What muscles are shown here and what is there common attachment?
Erector Spinae muscles- common tendon attaches to sacrum and iliac crest
- Iliocostalis (rib between angles and tubercles)
- Longissimus (transverse process of vertebrae)
- Spinallis (spinous process of vertebrae)
What group of muscles is shown here?
Transversospinalis
Located between the transverse and spinous processes
What movements does the atlanto-occipital joints allow?
Flexion and Extension of the neck- main movement
A little lateral flexion and rotation
What is the main movement of the Atlanto-axial joint?
Rotation - shaking head no
Within the spinal colomn, at which vertebral level does the subarachnoid space end?
S2
When administering a spinal anesthetic/epidural, what is the safest vertebral level to insert the needle?
L3/4
Spinal cord ends at level L2 and subarachnoid space ends at level S2. Want to get somewhere in the middle as the needle tip can brush past the cauda equina and avoid damaging the nerves.
Describe the anatomy of caudal anesthesia
Local anesthetic is injected into the sacral hiatus into the epidural space. This anestetises the sacral spinal nerve roots of the cauda equina.
What is a laminectomy?
The removal of one or more spinous processes and the adjacent laminae. Gives access to/relives pressure on the spinal cord or nerve roots.