PNS (anatomy)

Nerve

Nerve

bundle of neuron fibers outside CNS; classified by direction

Endoneurium

tissue around each neuron fiber

Perineurium

tissue around a group of neuron fibers

Epineurium

tough fibrous sheath around all fascicles

Mixed Nerves

sensory and motor fibers

Afferent

(sensory) carry impulses towards CNS

Efferent

(motor) carry impulses away from CNS

Cranial Nerves

12 pairs, head and neck, mostly mixed nerves

Olfactory

(sensory) smell

Optic

(sensory) vision

Oculomotor

4 of 6 fibers to eyeball, eyelid, and pupil size

Trochlear

(motor) one external eye muscle

Trigeminal

(sensory) skin of face, nose, mouth, chewing

Abducens

(motor) move eyes side to side

Facial

facial expressions, salvia, taste buds

Vestibulocochlear

(sensory) balance and hearing

Glossopharyngeal

(motor) neck, swallowing, saliva, tastebuds

Vagus

(sensory + motor) pharynx, larynx, abdominal, viscera, help digest

Accessory

(motor) activate sternocleidomastoid + trapezius

Hypoglossal

(motor) control tongue movements, sensory carry impulses from tongue.

Spinal Nerves

31 pairs, named for region of cord, dorsal(small), ventral(.5 inches)

Plexuses

serve motor and sensory needs

Cervical plexus

(C1-C5), diaphragm, shoulder, neck

Brachial Plexus

(C5-C8, T1) deltoid, triceps, forearm, muscles of hand

Lumbar Plexus

(L1-L4) low abdomen, butt, anterior thighs, skin of leg and thigh, small hip muscles, hip joint

Sacral Plexus

(L4-L5, S1-S4) lower trunk, posterior thigh, leg and foot, muscles of hip

Autonomic Nervous System

no control over it, regulate cardiac muscles, smooth muscles, glands. Homeostasis relies on it

Sympathetic Division

"flight or fight," continues until hormonesbreak down

Parasympathetic Division

"resting and digesting," regulate calm heart rates

Both divisions

they work in a dynamic balance (NOT ALL OR NONE).

Blood vessels

only controlled by sympathetic

Nervous system

first month of development, highest metabolic rate

Birth

smoking, alcohol, drugs= cerebral palsy, no oxygen

After birth

no more neurons are formed after birthed

Boxing and Drinking

small brain, dementia