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Nervous SystemCh 50

The brain & friends

Purpose•Communication•Relays _______•______ changes inside and out

Basic Cell•______–Sends signals called impulses

3 types of neurons•______: eye to brain•Motor: Brain-spine-muscles

•________: Connects the other Two

Neuron Parts•____

•______

•_____

•___________

Myelin _____•Made by _______ cells

•conducts impulses _____

• Increases w/ smarts•_____ substance

______ Potential•Na+ is allowed in

Threshhold•Strength of a ________ to cause a response–Ex. toilet flush model

Synapse• Information passage

•_______ signals–_________ _________

Divisions of the Nervous system•_______ NS

–Brain & spinal cord•________ NS

–Everything else–______ to CNS and Efferent

Brain (preview page)•Parts–________–Cerebral cortex–________–Brain stem

Cerebrum•_____ part–All _______ activity•Intelligence, learning…

4 lobes •______•Parietal•_______•occipital

2 hemispheres•L&R control ______ side of body

cerebral cortex•Outer layer–“____ matter”

Cerebellum

•____________•Learning a new physical activity difficult

Brain Stem•Connects to _____ cord

•Reptilian brain

Medulla ________• Involuntary functions–Breathing, _______, heart rate, coughing

Thalamus•Sensory ______•______ is only ________

___________•Hunger, thirst, fatigue, anger, temperature

Brain Function•Cerebral cortex–Locations of specifics

–Wilder Penfield

Brain Waves•Electroencephalogram (EEG)

•Weak ______ signals

Sleep•Lowest level of brain activity

•Brain needs 5-9 hours, body-3 hours

Memory•Long-term/short term

•_____ stick best•More ______ better

Motor Division a part of the ________ NS•_______ nervous system

•________nervous system (smooth muscle control)

Reflexes

•______ arch -sensor, motor, effector muscles work w/out brain

Sensory Division (preview page)

•Sight•_______•Smell•_______•Touch

Vision

•Light image sensing

•_ layers in eyes

Outer layer•______- whites- maintains shape & attatches muscle

•______ -light entry

Middle layer•Anterior chamber–________ humor

Middle layer• Iris- gives eye _____–Holds blood vessels

–Regulates____ size

Middle layer•Pupil- black ______ for light entry

Middle layer•Lens- ______ behind pupil bends light for focus

Middle layer•______ chamber- filled with vitreous humor(Liquid)

Inner Layer•______- with ____________ makes images

Inner Layer•Cones- ______•_____- b&w

Hearing

•_________•Sense

Pitch & volume

•_______ (hammer)

•______(anvil)

•______(stirrup)

•_______ moves sound to the auditory nerve

Balance Semicircular Canal•____________ stones for balance

Smell•_________ are cause

•Not much is known about it

Taste•Taste buds- 4 types–_____, salty, _____, bitter

•Related to smell