anatomy nervous system

nervous system

body's electrical system

central nervous system

brain and spinal cord

central nervous system function

integration and command center

peripheral nervous system

nerves and ganglia outside brain and spinal cord

peripheral nervous system function

connects central nervous system to limbs and organs

divisions of PNS

sensory (afferent) and motor (efferent)

sensory (afferent) division

carries nerve impulses from external stimuli into the brain

motor (efferent) division

muscles and glands perform functions as instructed by the CNS

divisions of motor division

somatic and autonomic

somatic nervous system

voluntary skeletal muscle movements

autonomic nervous system

internal and involuntary functions

examples of internal and involuntary functions

smooth muscle, cardiac muscle, and glands

divisions of autonomic nervous system

sympathetic and parasympathetic

sympathetic division

fight-or-flight

sympathetic division functions

increased heart rate, dilated pupils and bronchioles, restricted blood to skin, stored sugar in bloodstream, and inhibited digestion

parasympathetic divison

rest-and-digest annd energy conservation

parasympathetic division functions

slowed pulse, constricted pupils and bronchioles, and blood is pumped to brain and gut

how can you switch from sympathetic to parasympathetic?

by breathing or drinking water

neurons

building blocks of nervous tissues

neuron function

nerve cells that get excited and send electric signals

neuron characteristic

amniotic, long lifespan, high metabolic rate, and first cells to die in limited oxygen

amniotic

do not replicate or undergo mitosis

neuron cell structures

dendrites, soma, axon, and the myelin sheath

dendrites

external branches that receive information

are dendrites afferent or efferent?

afferent, into the cell body

soma (cell body)

nucleus and organelles

axon

where action potentials leave the cell

are axons afferent or efferent?

efferent, leave the cell body

safety pin cycle

stimuli enters dendrite, action potential, leaves through axon

myelin sheath

insulated fat layer that speeds up action potentials

who produces the myelin sheath?

oligodendrocytes and schwann cells

glial cells

neuron-supporting cells

CNS glia

astrocytes, microglia, ependymal cells, and oligodenrocytes

astrocytes

star-shaped and anchor blood cells to neurons

microglia

carry out phagocytosis

oligodendrocytes

form myelin sheath around axon

ependymal cells

make cerebrospinal fluid

PNS glia

schwann cells and satellite cells

schwann cells

form myelin sheath around axon

satellite cells

anchor blood cells to neurons

white matter

myelinated axons

gray matter

unmyelinated axons

brain matter

gray outside, white inside

spinal cord matter

white outside, gray inside

brain regions

cerebrum, cerebellum, brain stem, gyri, and sulci

cerebrum

visible majority with 2 hemispheres

cerebellum

fine motor movements

cerebellum location

under occipital lobe

3 sections of the brain stem

medulla oblongata, pons, and midbrain

gyri

bumps on the brain

sulci

grooves between gyri

fissure

a very deep sulcus

brain lobes

frontal, parietal, occipital, and temporal

frontal lobe

primary motor function

parietal lobes

primary sensory function

occipital lobe

vision

temporal lobes

hearing and integrating smells into memory

meninges

3 protective layers around the brain

dura mater

tough and dense outer layer

arachnoid mater

all blood vessels that feed the brain

pia mater

soft, innermost layer of the brain

how many cranial nerves are there?

12 pairs

CN I

olfactory nerve

CN I function

sense of smell

CN I fiber

sensory, afferent

CN II

optic nerve

CN II function

vision

CN II fiber

sensory, afferent

CN III

oculomotor nerve

CN III function

moves eyeball and eyelid, ocular constriction, and accomodation

CN III fiber

motor, efferent

CN IV

trochlear nerve

CN IV function

moves eyes up, down, and in

CN IV fiber

motor, efferent

CN V

trigeminal nerve

CN V function

moves jaw muscles and senses pain, temperature, and touch

CN V fiber

mixed, both afferent and efferent

CN VI

abducens nerve

CN VI function

moves eyeballs laterally for tracking

CN VI fiber

motor, efferent

CN VII

facial nerve

CN VII function

facial expressions, tears and saliva, and taste at front of tongue

CN VII fiber

mixed, both afferent and efferent

what is the only taste CN VII cannot sense?

bitter

CN VIII

vestibulocochlear nerve

CN VIII cochlear functions

hearing, ear vibrations, understanding in temporal lobe

CN VIII vestibular functions

balance and equilibrium

CN VIII fiber

sensory, afferent

CN IX

glossopharyngeal nerve

CN IX function

taste in back of tongue, swallowing, and triggers epiglottis

CN IX fiber

mixed, both afferent and efferent

CN X

vagus nerve

CN X motor functions

autonomic actions of heart, lungs, intestines, and stomach

CN X sensory functions

taste around area of epiglottis, coughing

CN X fiber

mixed, both afferent and efferent

CN XI

accessory nerve

CN XI function

shrugs shoulders, pulls neck down, protects neck

what muscles does the CN XI control?

sternocleidomastoid and trapezius

CN XI fiber

motor, efferent

CN XII

hypoglossal nerve