PRELIMS: Peripheral Neuropathies Flashcards
What are the components of the Peripheral Nervous System (PNS)?
12 pairs of cranial nerves, 31 pairs of spinal nerves, and plexi (Brachial Plexus and Lumbosacral Plexus).
What are the three connective tissue sheaths of peripheral nerves?
Endoneurium (surrounds individual nerve fibers), Perineurium (surrounds nerve bundles), Epineurium (surrounds the entire nerve).
What is the function of the Endoneurium?
It surrounds each individual nerve fiber and provides a protective layer.
What is the function of the Perineurium?
It surrounds nerve bundles or fascicles, providing strength and acting as a diffusion barrier.
What nerves are formed by the anterior rami of C5 to T1?
The Brachial Plexus.
What is the function of the Epineurium?
It surrounds the entire peripheral nerve, providing overall protection and support.
What are the major trunks of the Brachial Plexus?
Upper Trunk (C5 + C6), Middle Trunk (C7), Lower Trunk (C8 + T1).
Name the major nerves originating from the Lateral Cord.
Musculocutaneous Nerve, Lateral Median Nerve.
What muscle does the Dorsal Scapular Nerve innervate?
Rhomboids (minor and major) and Levator Scapulae.
What are the main types of axons in the peripheral nervous system?
Myelinated and Unmyelinated Axons.
What muscle does the Long Thoracic Nerve innervate?
Serratus Anterior.
Name the major nerves originating from the Medial Cord.
Ulnar Nerve, Medial Cutaneous Nerve of the Arm and Forearm, Medial Median Nerve.
What is the effect of myelination on nerve conduction speed?
Myelinated axons conduct electrical impulses faster than unmyelinated axons.
Name the major nerves originating from the Posterior Cord.
Thoracodorsal Nerve, Axillary Nerve, Radial Nerve.
