PNS - Revision Flashcards
What is a collection of cell bodies called when in the PNS?
Ganglion
What is a multipolar neurone and where can it be found?
2 or more dendrites
ALL motor neurones of skeletal muscles and ANS
Cell body in CNS
What is a unipolar neurone and where can it be found?
Double process
Sensory
Cell body in PNS
What is a nerve?
A collection of axons surrounded by connective tissue and blood vessels
How many spinal nerves are there and how are they arranged?
31: 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
Where are spinal nerves found?
In the intervertebral foramina
What will the posterior rami supply?
Posterior body wall
What will the anterior rami supply?
Anterolateral body wall
Where will ALL sensory axons pass from?
Spinal nerve into the posterior root then into the posterior rootlets then into the posterior horn of the spinal cord
Where will ALL motor axons pass from?
Anterior horn
Anterior rootlets
Anterior root
Spinal nerve
What will each spinal nerve pain suppy a body segment with?
General sensory supply to all structures
Somatic motor supply to all skeletal muscle
Sympathetic nerve supply to skin and smooth muscle arterioles
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
What are common landmark dermatomes?
Nipple; T4 Umbilicus; T10 Thumb; C6 Post scalp, neck and shoulder; C2-4 Upper limb; C5-T1 Lower limb, gluteal and perineum; L2-Co1
What is shingles?
Viral disease of the spinal ganglia causing a classic, dermatomally distributed vesicular rash
What is a nerve plexus?
Intermingled anterior rami from a number of adjacent spinal nerves
What spinal nerves are involved in the cervical plexus?
C1-4
What spinal nerves are involved in the brachial plexus?
C5-T1
What spinal nerves are involved in the lumbar plexus?
L1-L4
What spinal nerves are involved in the sacral plexus?
L5-S4
Where does sympathetic outflow originate from?
T1-L2 lateral horns
What are the different routes for a sympathetic nerve?
Ascend down symp trunk then synapse
Synapse at level of entry
Descend down symp trunk then synapse
Pass through symp trunk without synapsing to enter abdominopelvic splanchnic nerves
Describe symp outflow to the heart
Presynaptic axons synapse in T1 or cervical paravertebral ganglia
Post synaptic axons pass in cardiopulmonary splanchnic nerves to the SA and AV nodes in myocardium
Describe symp outflow to lungs
Presynaptic axons synapse in upper thoracic paravertebral ganglia
Postsynaptic axons pass in cardiopulmonary splanchnic nerves to bronchiolar smooth muscle and mucionus glands
Describe symp outflow to adrenal medulla
Presynaptic axons pass through aoritocrenal ganglion to synapse directly into adrenal medulla
Where will parasymp outflow originate from?
CN 3,7,9,10
Sacral spinal nerves
How will parasymp outflow travel around the body?
Ciliary ganglion Pterygopalatine ganglion Otic ganglion Submandibular ganglion Vagus nerve
