anatomy pns

Cranial nerves in order

Olfactory (I), Optic (II), Oculomotor (III), Trochlear (IV), Trigeminal (V), Abducens (VI), Facial (VII), Vestibulocochlear (VIII), Glossopharyngeal (IX), Vagus (X), Accessory (XI), and Hypoglossal (XII)

Olfactory function

Process and detect odor

Sensory neuron function

Detect/sense stimuli

Motor neuron function

Form/coordinate muscular movements

Inter neuron function

Connect sensory and motor neurons, processes stimuli information

olfactory nerve

controls smell

optic nerve

controls vision

oculomotor nerve

controls the eye muscle, eyeball, and eyelid

trigeminal nerve

motor fibers for chewing muscles

trochlear nerve

motor fivers to one eye muscle

abducens nerve

motor fiber to roll eye

facial nerve

sensory for taste, motor fibers to face for expressions

vestibulocochlear nerve

sensory for balance and hearing

hypoglossal nerve

motor fibers to tongue

accessory nerve

motor fibers to neck and upper back

glossopheryngel nerve

sensory for taste, motor fibers to pharynx (swallowing)

vagus nerve

sensory and motor nerves to pharynx, larynx, heart, and digestion

reflex

rapid, predictable, invooluntary responses to stimuli

reflex arc

direct route from a sensory neuron, to an interneuron, to an effector.

Somatic reflexes

stimulate skeletal muscles (ex: hand on stove)

autonomic reflexes

Regulate smooth muscles, glands, heart (ex: BPM)

Action potential process

the plasma membrane is polarized meaning the axon is ready to send a message. Depolarization will begin to occur as sodium begins to flow inside. The message is sent as a change in charge takes place. Repolarization occurs as the axon returns to polarization

What can speed up or slow down action potentional?

stimulants (ex. Coffee, meth) may speed it up. Anesthesia may slow it down.

Cell body

contains all typical cell parts (nucleus, large nucleolus)

dendrites

receive incoming messages

Axon

Sends messages away from cell body

Schwan cell

produces myelin sheaths in jelly-roll like fashion (travels quicker) made of fat

nodes of ranvier

gaps in myelin sheath along axon (message travels quicker w/ gaps)

peripheral nervous system

nerves that branch out from brain and spinal cord

central nervous system

brain and spinal cord