Lab 6 - Major Nerves and Spine

Dura mater

Arachnoid mater

Pia mater

Dura mater

What makes up the Dura mater?

periosteal and meningeal

Pia mater

Arachnoid mater

Spinal dura mater

Dorsal root ganglion

Spinal nerve

Dorsal root

Ventral root

What is the nerve root?

the initial segment (axon) of nerve leaving the central nervous system

What do ventral roots contain?

motor neuron axons

What do dorsal roots contain?

sensory neuron axons

What is the spinal nerve?

fusion of dorsal and ventral roots

Spinal nerve

Ventral ramus of spinal nerve

Dorsal root ganglion

Dorsal ramus of spinal nerve

What is the ramus?

division of spinal nerve with mix of sensory and motor fibers

What is the dorsal rami?

serve skin and musculature of posterior trunk

What is the ventral rami?

combine to form nerves plexuses which diverge again

a) _____

dorsal root

b) _____

dorsal root ganglion

c) _____

spinal nerve

d) _____

ventral root

How many total pairs of spinal nerves?

31

How many cervical nerves?

8

How many thoracic nerves?

12

How many lumbar nerves?

5

How many sacral nerves?

5

How many coccygeal nerves?

1

Where do all spinal nerves arise from?

dorsal and ventral roots

Cervical nerves

Thoracic nerves

Lumbar nerves

Sacral nerves

Coccygeal nerves

Cervical plexus

Brachial plexus

Lumbar plexus

Sacral plexus

________ nerve innervates the diaphragm

Phrenic

Phrenic nerve

What region does the cervical plexus serve?

muscles of shoulder and neck

What does the cervical plexus arise from?

ventral rami of C₁-C₅ and T₁

What region does the brachial plexus serve?

skin and muscles of the arm and shoulder

Name the 5 major peripheral nerves

Axillary, Radial, Musculocutaneous, Ulnar, Median

What does the brachial plexus arise from?

ventral rami of C₅-C₈ and T₁

What plexus do the peripheral nerves divide from?

brachial

Axillary nerve

muscle and skin of shoulder

Radial nerve

posterior muscles of arm, forearm, and hand

skin of posterolateral surface of entire limb (think tricep area)

Musculocutaneous nerve

flexor muscles of anterior arm

skin of anterolateral forearm

Ulnar nerve

flexor muscles of anterior forearm

skin of medial hand

What nerve “hurts” when you hit your “funny bone”?

ulnar nerve

Median nerve

flexor muscles of anterior forearm and hand

skin of lateral hand

Axillary nerve

Radial nerve

Musculocutaneous nerve

Ulnar nerve

Median nerve

The ______ nerve is the largest nerve in the lumbar plexus

femoral

What does the femoral nerve innervate?

anterior thigh muscles and skin of anteromedial surface of entire limb

What does the lumbar plexus arise from?

ventral rami of L₁-L₄

What region does the lumbar plexus serve?

abdominopelvic region and anterior thigh

Femoral nerve

Sciatic nerve

What does the sacral plexus arise from?

L₄-S₄

What region does the sacral plexus serve?

buttock, posterior surface of the thigh, and all sensory and motor fibers of the leg and foot

______ nerve is the major nerve of the sacral plexus

Sciatic

What is the largest nerve in the body?

Sciatic nerve