Innervations

Question 1

The Long Thoracic Nerve comes from what nerve roots?

Answer 1

The Long Thoracic Nerve comes from the nerve roots

C5-C7

Question 2

The phrenic nerve comes from what nerve roots?

Answer 2

The phrenic nerve originates in spinal nerves C3-C5.

It is the innervation for the diaphragm.

Question 3

What pelvic oriented organ(s) has parasympathetic innervation originating in the cervical spine?

Answer 3

The kidneys and proximal ureters are the only pelvic oriented organs which are innervated by C1 and C2 (the Vagus nerve)

All others are innervated by the pelvic splanchnic

Question 4

What nerve is tested by the Achilles reflex?

Answer 4

S1 is tested by the Achilles reflex.

S1 is responsible for the dermatome covering much of the posterior thigh and calf and lateral lower leg.

S1 also provides innervation for the gastrocnemius

Question 5

A lesion in L4 would result in what type of deficits?

Answer 5

L4 is responsible for medial lower leg sensation, ankle dorsiflexion, and part of knee extension.

Test L4 with the patellar tendon reflex

Question 6

What nerve is responsible for sensation in the dermatome covering the medial buttocks at the natal fold distally to the medial malleolus?

Answer 6

The dermatome covering the medial buttocks at the natal fold is S2. It does have some motor innervation of the hamstrings, but is not tested by any commonly used muscle stretch reflex.