Lab Section 4 Flashcards
what is a radiculopathy?
damage to a spinal nerve, a dorsal root or a ventral root
what is a myotome and a dermatome?
a myotome is all of the muscles supplied by a spinal nerve and a dermatome is all of the skin supplied by a spinal nerve
what spinal segments contribute to the cervical plexus and what does it supply?
C1-4
the muscles and skin of the neck
what spinal segments contribute to the brachial plexus and what does it supply?
C4-T1
muscles and skin of the arm
what spinal segments contribute to the lumbar plexus and what does it supply?
L1-4
the inguinal region, the lower abdominal region and the anterior and middle compartments of the thigh
what spinal segments contribute to the sacral plexus and what does it supply?
L4-S4
the gluteal region, the posterior compartment of the thigh and the entire leg and foot
at what level does the spinal cord end? what does it continue as?
at L1
continues as the cauda equina
describe the divisions of the sciatic nerve.
sciatic nerve innervates the hamstrings before dividing into the tibial and common fibular nerves
the common fibular divides into the superficial and deep fibular nerves
what is the difference between a peripheral mononeuropathy and a plexopathy?
a peripheral neuropathy is of one peripheral nerve while a plexopathy may be more diffuse
under what conditions could an incomplete lesion of a peripheral nerve exist? what are the symptoms?
with a nerve entrapment
partial loss of sensation or pasesthesia and weakness of the muscles the nerve supplies
what would cause a radiculopathy and what is it associated with?
a herniated disc compressing the root
burning or tingling of the dermatome with reduced sensation and reduced strength of the muscle supplied by it
which disc herniations are most common?
C6, C7, L5 and S1 (lumbosacral far more common)
what test is helpful for diagnosis of nerve root compression in the lumbosacral region?
straight leg raising test or the crossed straight leg raising test because it results in traction of the nerve roots
decreased biceps reflex could be caused by which two radiculopathies? what differentiates them?
C5 and C6
C6 also has a decreased brachioradialis reflex
decreased triceps reflex is caused by which radiculopathy?
C7
a decreased patellar reflex comes with which radiculopathies? what other symptom is common?
L2-3
waddling gait
damage to L5 gives what positive sign?
The trendelenberg sign (patient lifts leg up and the hip sags)
loss of the achilles tendon reflex can point to which radiculopathy?
S1
what type of information is contained within the cell bodies of the intermediate gray area?
a mixture of sensory and motor neurons
what type of axons carry epicritic information and where do they enter the dorsal cell column?
large myelinated axons that enter medially within the dorcal funiculus
which large myelinated axons synapse onto the dorsal horn?
axons that inhibit pain signals
what type of axons carry protopathic information and how do they travel up the spinal cord?
small un myelinated (or with little)
ascend or descend in Lissauer’s tract a few segments and synapse on the dorsal horn contralaterally
which sensory neurons may project directly to motor neurons and why?
proprioceptive
because they contain information about muscle length and tension to govern reflexes