Nerve Plexus

Question 1

Cervical plexus

Answer 1

C1-C4
muscles in neck
diaphragm
Nerves : phrenic (C3, C4, C5)
cranial nerves: accessory, hypoglossal

Question 2

Brachial plexus

Answer 2

C5-T1
arm muscles, flexion and extension
Nerves: 
axillary (C5, C6)
musculocutaneous (C5, C6, C7)
median (C5, C6, C7, C8, T1)
ulnar (C8, T1)
radial (C5, C6, C7, C8, T1)

Question 3

Lumbar plexus

Answer 3

T12-L4
some low abdomen
genitalia
anterior and medial thigh (quads)
medial surface of leg from knee to foot
Nerves:
femoral (L2, L3, L4)
obturator

Question 4

Sacral plexus

Answer 4

L4-S4
butt and low limb (sole of foot)
external genitalia
Nerves: 
sciatic (L4, L5, S1, S2, S3)
tibial 
common fibular