PNB Exam 3 Module IV-4

alpha neurons

gamma motor neurons

Adjust the muscle spindle, a sensory receptor inside the muscle that detects stretching.

Ipsi vs contralateral

Spine functional anatomy

Spinal nerve diagnostic tools

Ascending vs Descending Tracts

Named from origin, either spino-cns for ascending or cns-spinal for descending tracts. Descending=motor/autonomic. Ascending= sensory

Dorsal vs Ventral root, ascending vs descending

Dermatome vs Myotome

• Dermatome: An area of skin that sends sensory information into the nervous system through a particular spinal nerve root.

• Myotome: A group of muscles or muscle actions that receive motor commands from the nervous system through a particular spinal nerve root.

Plexus

For example, a nerve traveling into your arm may contain fibers associated with C5, C6, C7, C8, and T1.

These fibers can join together and redistribute through a structure called a plexus.

A plexus is essentially an intersection where nerve fibers from different spinal levels mix and reorganize.

Cervical Plexus

Phrenic Nerve

Part of the cervical Plexus.

Brachial Plexus

Different Brachial Nerves

Ulnar Nerve

Carpal Tunnel

Lumbar, Sacral & Coccygeal + Femoral Plexi

Monosynaptic vs Polysynaptic Reflex Arc

Patellar Reflex

Stretch (Myotatic) Reflex

Golgi Tendon Organ

Withdrawal Reflex

Crossed Extensor Reflex

Babinski Reflex

Meningitis of the spine, spinal taps?

No spinal cord below L2

Spinal Stenosis