AP Biology

Nervous SystemsPart 4

LE 48-12

Hyperpolarizations

Graded potential hyperpolarizations Graded potential depolarizations

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stimuli

+50

Depolarizations

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stimuli

+50

Action potential

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stronger depolarizing stimulus

+50Actionpotential

6

Action potential moving toward the CNS

Cell body

Schwann cell

Depolarized region(node of Ranvier)

Myelinsheath

Axon

Dendrites of the neurons

Summation and the Threshold potential

Hyperpolarizations

Graded potential hyperpolarizations Graded potential depolarizations

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stimuli

+50

Depolarizations

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stimuli

+50

Action potential

5Time (msec)

Restingpotential

43210

Threshold

–100

–50

0

Mem

bra

ne

po

ten

tial

(m

V)

Stronger depolarizing stimulus

+50Actionpotential

6

Stimulus receptorsLighttouch

Pain Cold HairHeat

Hairmovement

Strongpressure

Hypodermis

Nerve Connectivetissue

Dermis

Epidermis

Inside the Cochlea

Cochlear Duct

How it all works

• https://www.youtube.com/watch?v=qgdqp-oPb1Q

Balance and the Inner ear

Taste

Smell

How it all works

• https://www.youtube.com/watch?v=WavjbJhiRAE

.Lateral line

Lateral line canal

Epidermis NeuromastOpening oflateral line canal

Scale

Lateral nerveSegmental muscles of body wall

Cupula

Supportingcell

Nerve fiber

Sensoryhairs

Hair cell

Statosyst

Statolith

Sensorynerve fibers

Ciliatedreceptor cells

Cilia

Crane Fly

.

1 mm

Tympanicmembrane

Tympanum for hearing