Gross Anatomy of the PNS

Question 1

<p><p><p><p>Define Nucleus</p></p></p></p>

Answer 1

<p><p><p><p>a mass of gray matter (cell bodies) in the central nervous system, especially such a mass marking the central termination of a nerve</p></p></p></p>

Question 2

<p><p><p><p>Define Ganglion</p></p></p></p>

Answer 2

<p><p><p><p>a group of nerve cell bodies, located outside the central nervous system</p></p></p></p>

Question 3

<p><p><p><p>Describe multi-polar neurones and their function</p></p></p></p>

Answer 3

<p><p><p><p>2 or more dendrites
Cell body in the CNS

Skeletal muscle innervation and Autonomic nervous system</p></p></p></p>

Question 4

<p><p><p><p>Describe uni-polar nerones and their function</p></p></p></p>

Answer 4

<p><p><p><p>Two processes
Cell body in the PNS

Sensory Neurones</p></p></p></p>

Question 5

<p><p><p><p>Define a 'nerve'</p></p></p></p>

Answer 5

<p><p><p><p>A collection of axons surrounded by CT and blood vessels

Can contain multiple modalities and are often named</p></p></p></p>

Question 6

<p><p><p><p>List the Cranial Nerves including:</p>

<p>(i) Numerical Value</p>

<p>(ii) Common name</p>

<p>(iii) Modality (motor, sensory or both)</p>

<p>(iv) Location of CNS origin</p>

<p>(v) Describe route and cranial exit</p>
</p></p></p>

Answer 6

<p><p><p><p>CN I olfactory nerve, sensory (special), forebrain</p>

<p>CN II optic nerve, sensory (special), forebrain</p>

<p>CN III oculomotor nerve, motor, midbrain</p>

<p>CN IV trochlear nerve, motor, midbrain</p>

<p>CN V trigeminal nerve, both, pons</p>

<p>CN VI abducent nerve, motor, PMed junction</p>

<p>CN VII facial nerve, both, PMed junction</p>

<p>CN VIII vestibulocochlear nerve, sensory (special), PMed junction</p>

<p>CN IX glossopharyngeal nerve, both, medulla</p>

<p>CN X vagus nerve, both, medulla</p>

<p>CN XI spinal accessory nerve motor spinal cord</p>

<p>CN XII hypoglossal nerve motor medulla</p>
</p></p></p>

Question 7

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<p>Label Cranial Nerves</p>

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<p>https://sketchfab.com/models/82d87cb89d6c48f0984a59c4f2a4cf9a</p>

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Answer 7

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Question 8

<p><p><p>How many Spinal nerves are there? Describe them</p></p></p>

Answer 8

<p><p><p>31 Pairs

~~~
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
~~~

Found within the intervertebral foraminae</p></p></p>

Question 9

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<p>label spinal nerve</p>

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Answer 9

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Question 10

<p><p>Define 'Dermatome' and list remarkable sections

| (Foerster map)</p></p>

Answer 10

<p><p>The area of skin supplied with afferent nerve fibers by a single posterior spinal root

Male nipple - T4
Umbilicus - T10

Posterior scalp, neck, shoulder - C2-C4
Upper limb - C5-T1
Lower limb, gluteal, perineal - L2-Co1</p></p>

Question 11

<p><p>Define 'plexus' and list plexuses involving spinal nerves</p></p>

Answer 11

<p><p>A network or tangle, chiefly of veins or nerves

Cervical C1-C4
Brachial C5-T1
Lumbar L1-L4
Sacral L5-S4</p></p>

Question 12

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<p>Peripheral Nerve names</p>

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Answer 12

Question 13

Describe Sympathetic Outflow

Answer 13

Originates from control centres in the brain

Passes down spinal cord

T1 to L2 have lateral horns – cell bodies

“presynaptic” sympathetic axon - ‘motor’ innervation so passes through anterior rootlets/root

Take 1 of 4 routes

Present in all spinal nerves

Question 14

Detail sympathetic outflow to the heart

Answer 14

presynaptic axons synapse in T1 or cervical paravertebral ganglia

postsynaptic axons pass in cardiopulmonary splanchnic
nerves to the SA & AV nodes & the myocardium

Question 15

Detail sympathetic outflow to the lungs

Answer 15

presynaptic axons synapse in upper thoracic paravertebral ganglia

postsynaptic axons pass in cardiopulmonary splanchnic nerves to the bronchiolar smooth muscle & mucous glands

Question 16

Detail sympathetic outflow to the abdominopelvis organs

Answer 16

presynaptic axons synapse in one of the prevertebral ganglia:

     - celiac ganglion of celiac plexus (foregut)
     - aorticorenal ganglion (kidney)
     - superior mesenteric ganglion of SM plexus (midgut)
     - inferior mesenteric ganglion of IF plexus (hindgut & pelvic/perineal organs)

Question 17

Detail sympathetic outflow to the adrenal medulla

Answer 17

presynaptic axons pass through the aorticorenal ganglion to synapse directly onto the adrenaline/noradrenaline secreting cells of the adrenal medulla

Question 18

Describe parasympathetic outflow

Answer 18

Leave CNS via:
CN III, VII, IX, X
Sacral spinal nerves

Ciliary ganglion - eye

Parasympathetic ganglia in head - lacrimal and salivary glands

Vagus nerve - organs of the neck, chest, abdomen up to mid-gut

Sacral spinal nerves - hindgut, pelvis, perineum