Nerve Plexuses & Peripheral Nerve Pathways

Question 1

Nerve Plexuses

Answer 1

Ventral rami of spinal nerves merge to form interconnected groups of nerves

Question 2

There are ___ spinal nerve plexuses

Answer 2

4

Question 3

What are the spinal nerve plexuses?

Answer 3

Cervical, Brachial, Lumbar, & Sacral

Question 4

Cervical Plexus

Answer 4

Formed by anterior rami of C1-C4 Spinal nerves

Question 5

Terminal Nerves innervate

Answer 5

Diaphragm & Neck muscles

Question 6

Brachial Plexus

Answer 6

Ventral rami of C5-T1
- Rami converge to form trunks, Separate into divisions, merge into cords, form terminal branches

Question 7

Simple order to follow

Answer 7

Roots-Trunks-Divisions-cords-branches

Question 8

Brachial Plexus

Answer 8

Innervations to upper extremity through 5 branches

Question 9

5 Branches of Brachial Plexus

Answer 9

• Axillary
• musculocutaneous
• Median
• Radial
• Ulnar

Question 10

It is the sensorimotor innervation to …

Answer 10

arm & hand

Question 11

Axillary Nerve

Answer 11

• C5-C6
• Innervates the deltoid and teres minor which position and stabilize the shoulder for reaching.

Question 12

Musculocutaneous Nerve

Question 13

Radial Nerve

Answer 13

• C5-T1
• innervates muscles that extend the elbow, wrist, fingers, & thumb
• Vital for manipulation and stable grasp
• innervation occurs proximal to the wrist

Question 14

Ulnar Nerve

Answer 14

• C8-T1
• innervates two muscules near the elbow that flex the wrist and fingers
• supplies samll muscles within the hand that are important for grip and lateral key pinch

Question 15

Ulnar Nerve

Answer 15

• provides motor and sensory function to the hand and forearm

Question 16

Median Nerve

Answer 16

• C5-T1
• innervates key muscles that contribute to forearm pronation, finger flexion, and thumb motion
• Supplies valuable sensory innervation of the radial aspect of the palm & fingers to guide precise fine motor control & pinch

Question 17

Lumbar Plexus

Answer 17

• L1-L4
• Innervates muscles of pelvis and thigh

Question 18

2 Primary Motor Nerves

Answer 18

Femoral & Obturator

Question 19

Femoral Nerve

Answer 19

• L2- L4
• innervates the iliacus, quadriceps, pectineus, & sartorius
• Important for the motion & stability of the hip and knee as components of functional mobility

Question 20

Obturator Nerve

Answer 20

• L2-L4
• Innervates the adductors of the hip

Question 21

Sacral Plexus

Answer 21

innervate muscles adjacent to plexus
- superior & inferior gluteal nerves

Question 22

3 Motor Nerves

Answer 22

1. Sciatic
2. Tibial
3. Common Fibular

Question 23

Sciatic Nerve

Answer 23

• L4-S3
• Divides to form tibial & common fibular nerves
• Innervate the hamstrings & adductor magnus

Question 24

Tibial Nerve

Answer 24

• L4-S3
• goes down the posterior leg to innervate the gastrocnemius & soleus

Question 25

Common Fibular Nerve

Answer 25

- L4-S2 - passes around the anterior lower leg - innervates the ankle dorsiflexor & toe extensor muscles