Final Study Guide: Spinal Cord

Front 1

2 functions of spinal cord:

Back 1

1. serve as pathway for impulses between body and brain.

2. center of spinal reflexes.

Front 2

Pathway of a spinal reflex:

Back 2

stimuli -------> receptor -------> nerve impulses -------> dendrite of sensory neuron ----> dorsal root ganglion -------> axon of sensory neuron -------> spinal cord ----> interneuron -------> motor neuron -------> axon of motor neuron -------> effector
------> reflex occurs.

Front 3

4 features common to all spinal reflexes:

Back 3

1. Never more than 1 sensory neuron involved.

2. Cell body of sensory neuron lies outside the spinal cord in the dorsal root ganglion{spinal ganglion}.

3. Axon of sensory neuron always enters the spinal cord dorsally{posteriorly}.

4. Axon of motor neurons always leave the spinal cord ventrally{anteriorly}.

Front 4

The peripheral nervous system{PNS} is composed of :

Back 4

12 pairs of cranial nerves
31 pairs of spinal nerves

Front 5

a. List the name and numbers of the 5 types of spinal nerves:

Back 5

cervical - 8 pairs
thoracic - 12 pairs
lumbar - 5 pairs
sacral - 5 pairs
coccygeal - 1 pair

Front 6

b. Type of nerve?

Back 6

All are mixed nerves.

Front 7

c. Where are the cell bodies of their motor fibers located?

Back 7

They are located in gray matter of spinal cord.

Front 8

d. Where are the cell bodies of their sensory fibers located?

Back 8

They are located in the dorsal root ganglion { spinal ganglion }.

Front 9

e. Define plexus.

Back 9

A network of interlacing nerve fibers from several spinal nerves.

Front 10

f. 4 main plexuses

Hint: CBLS

Back 10

Cervical Plexus
Brachial Plexus
Lumbar Plexus
Sacral Plexus

Front 11

formed from nerve fibers from the 1st 4 cervical spinal nerves - nerves from this plexus supply the skin and muscles of neck and shoulders

Back 11

cervical plexus

Front 12

formed from nerve fibers of the last 4 cervical spinal nerves and the 1st thoracic spinal nerve - nerves from this plexus supply the skin and muscles of the upper limbs

Back 12

brachial plexus

Front 13

formed from nerve fibers from the last thoracic spinal nerve and the 1st 4 lumbar spinal nerves - nerves from this plexus supply the lower abdominopelvic region, buttocks, and anterior part of thighs

Back 13

lumbar plexus

Front 14

formed from nerve fibers of the last 2 lumbar nerves and the 1st 4 sacral nerves - nerves from this plexus supply the lower trunk, posterior surface of legs, and the feet

Back 14

sacral plexus

Front 15

one of the main nerves arising from the plexus is the phrenic nerve.

Back 15

Cervical Plexus

Front 16

one of the main nerves arising from the plexus is the axillary plexus.

Back 16

Brachial Plexus

Front 17

main nerve arising from the plexus is the femoral nerve.

Back 17

Lumbar Plexus

Front 18

main nerve arising from the plexus is the sciatic nerve.

Back 18

Sacral Plexus