CNS PNS, eyes, ears

what does the CNS consist of

spinal cord and brain

CNS function

recieve and interpert infromation, later generate a response

spinal cord

bundles of nerves from the base of the skull to lower back

spinal cord function

communication between CNS and PNS

what protects the spinal cord

vertebrae

dorsal root

enterance for sensory nerves to the spinal cord

ventral root

exit for motor nerves out of the spinal cord

what is a reflex

when the signal doesnt go all the way to the brain

why do we need the skull

protection

how many membranes around the brain

3

cerebrospinal fluid purpose

picks up wastes during sleep

absorbs impact

gives nutrients

why is it important for the cerebrospinal fluid to bring nutrients to the brain

not a lot of blood vessels to bring nutrients

meningitis

inflammation of the meninges by bacteria or virus

bacterial meningitis (dangerous/not as bad)

dangerous

viral meningitis (dangerous/not as bad)

not as bad

what does the amount of wrinkles of the brain mean

more brain activity bc more surface area

cerebrum

outer layer of nervous tissue

how many hemispheres of the cerebrum

2

what connects the cerebrum hemspheres

corpus callosum

cerebrum lobes

occipital, temporal, parietal, frontal

occipital lobe function

vision

temporal lobe function

hearing

parietal lobe function

sensory info and spatial awareness

frontal lobe function

personality, decision making

cerebellum function

coordination, fine movements and balance

hypothalamus function

main control center → homeostasis

secretes hormones → endocrine gland

brain stem components

midbrain, pons, medulla oblongata

midbrain function

connects main brain to the pons and medulla

pons function

a relay station between cerebrum, cerebellum and spinal cord

medulla oblongata function

controls the autonomic NS

PNS components

somatic and autonomic systems

somatic system function

collects info from environment

controls voluntary movements through motor and sensory nerves

autonomic system function

internal organs and environment

nerotransmitters in the sympathetic system

epinephrine and norepinephrine

sensation

ability to detect stimulusp

perception

how brain interprets stimulus

sensory adaptation

brain stops perceiving current stimulus to prioritize another one

sclera function

outer white layer for protection

cornea function

anterior transparent part of sclera- allows light into the eye and bends it

choroid function

middle layer that contains blood vessels

aqueous humor function

liquid that maintains the shape of cornea

iris function

sphincter muscle that controls the size of the pupil → how much light comes in (coloured part of the eye)

pupil function

opening into the eye not a structure

lens function

bends the light more and creates focus of images

how is lens affected by age

becomes stiffer- reduces ability to focus

vitreous humor

gel substnace that keeps the shape of the ball

retina function

inner layer that contains photoreceptors wh

what are the photo receptors on the retina

rods and cones

rods function

specialize in dim lightingc

cones function

specialize in vision in bright light and coulour

fovea centralis

indent in the back of the ball with the most cones meaning the sharpest vission

blind spot

where optic nerve attaches to the retina so no photoreceptors

process of light entering the eye

cornea → aqueous humor → pupil (dilates or contracts) → lens bends the light → retina (stimulates rods and cones) → optic nerve

cataract

clouding of the lens do to aging and uv exposure

myopia

near sightedness- ball is too long and light spread out too much

hyperopia

far sightedness- ball is too short

what lens corrects myopia

concavewh

what lens corrects hyperopia

convex

astigmatism

cornea is misshapen so light bends not uniformly

functions of the ear

hearing and balance

what are the components of the ossicles

malleus, incus, stapes

malleus nickname

hammer

incus nickname

anvil

stapes nickname

stirrnup

function of the outer ear

collection of sound waves

components pf the outer ear

pinna, auditory canal, earlobe

pinna

cartilage that collects sound and send it to auditory canal

auditory canal

lined with cilia and cells that produce cerumen to move debris outwards

cerumen

earwax

middle ear function

amplify sound

middle ear components

tympanic membrane, ossicles, oval window, eustachian tube

tympanic membrane (+ nickname)

vibrates when sound hits, eardrum

ossicles

bones that pass vibrations to the oval window

oval window

membrane at the enterance of the cochlea that starts with liquid waves

eustachian tube

connects ear to the respiratory tract to regulate pressure

inner ear function

filled with fluid converts sound into nerve impulses

parts of the inner ear

cochlea, organ of corti

cochlea

filled with liquid

organ of corti

cell lining inside the cochlea with stereocilia that receive the sound and send the impulses to the auditory nerve

where do impulses go from the auditory nerve

temporal lobe

sound pathway

tympanic membrane, ossicles, oval window, wave moves fluid inside cochlea, if strong enough moves stereocilia, auditory nerve, temporal lobe

conduction deafness

prevents sounds reaching the cochlea

sensorineural deafness

prevents sound from converting into impulses

what parts are responsible for static balance

utricle, saccule

what parts are responsible dynamic balance

semicircular canals

where is information sent from the balance parts of the ear

cerebellum