thorax back nervous system

dorsal root

sensory

posterior

ventral root

motor

anterior

dura mater

“tough mother”

strong

arachnoid mater

spidery looking

carries blood vessels

pia mater

“delicate mother”

adheres tightly to surface for spinal cord

does spine need own blood supply

yes

cauda equina

approx L3

horses tail

where do cervical nerves exit

C1-C7 exit superior to their respective vertebrae

C8 exits inferior to C7 vertebrae

cervical plexus

C1-C5

brachial plexus

C5-T1

Phrenic n

C3-C5 (innervates diaphragm)

what does axillary supply

deltoid and teres

what does musculocutaneous supply

elbow flexors

what does radial supply

shoulder, elbow, wrist, and finger exteensors

what does median and ulnar supply

flexors of wrist and hand

what should you think of with lower back pain

sciatic nerve (sacral)

afferent fibers

sensory fibers

nerves conduct impulse to CNS

(TOWARD brain)

efferent fibers

motor fibers

nerves carry impulse to glands or muscles

(AWAY from brain)

5 components of reflex

receptor

sensory (afferent) neuron

integrating center

motor (efferent) neuron

effector

R S I M E

effects of aging on nervous system

brain reduces in size and weight

cortical neurons lost, blood flow decreases, neurotransmitter production is limited, and memory processing slows