What happens when a neuron’s membrane depolarizes?

Ther

e is

a n

et d

iffus

io...

Ther

e is

a n

et d

iffus

io...

The

neuro

n’s

volta

ge...

The

neuro

n ca

nnot s

...

The

insi

de of t

he c

ell..

.

20% 20% 20%20%20%

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1. There is a net diffusion of Na out of the cell.

2. There is a net diffusion of K into the cell.

3. The neuron’s voltage inside becomes more positive.

4. The neuron cannot send an action potential.

5. The inside of the cell becomes more negative relative to the outside

:60

A common feature of action potentials is that they:

Cau

se th

e m

embr

ane

..

Can

trav

el in

more

th..

Are

trig

gered

by

a de

...

Move

at t

he s

ame

spe.

.

Res

ult fro

m th

e diff

usi..

20% 20% 20%20%20%

0of5 :60

1. Cause the membrane to hyperpolarize and then depolarize.

2. Can travel in more than one direction on an axon.

3. Are triggered by a depolarization the reaches the threshold.

4. Move at the same speed along all axons.

5. Result from the diffusion of Na and K into the cell.

Where are neurotransmitter receptors located?

On th

e nucl

ear m

emb...

at t

he nodes

of R

anvi

er

On th

e post

synap

tic ..

.

On th

e m

embra

ne o

f t..

On th

e m

yelin

shea

th

20% 20% 20%20%20%

0of5 :60

1. On the nuclear membrane

2. at the nodes of Ranvier3. On the postsynaptic

neuron’s membrane4. On the membrane of

the synaptic vesicles5. On the myelin sheath

Which of these correctly describes the distribution of ions

in a resting neuron?

Na

outsid

e, K

insi

de

K o

utsid

e, N

a in

side

Pro

tein

s out

side;

K ..

.

Na

& K o

utsid

e; w

ate.

..

Ca

outsid

e an

d insi

de

20% 20% 20%20%20%

0of5

:60

1. Na outside, K inside2. K outside, Na inside3. Proteins outside; K

and Na inside4. Na & K outside;

water inside only5. Ca outside and

inside

The large intestine in humans:

Dig

ests

all

types

of f

ood.

Is th

e lo

ngest

par

t of t

..

Abso

rbs

water

.

Is c

onnect

ed to

the

s...

All

of the

above

.

20% 20% 20%20%20%

0of5

1. Digests all types of food.

2. Is the longest part of the intestinal tract.

3. Absorbs water.4. Is connected to the

stomach.5. All of the above.

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If I roll a:

• 1 – On your own, no notes• 2 – On your own, with notes• 3 – With partner, no notes• 4 - with partner, with notes• 5 – as a class, no notes• 6 – as a class, with notes

From what you know about action potentials and synapses, propose three hypotheses for how various anesthetics

might prevent pain.

The Skeletal System

Basic Functions of a Skeleton?

Types of SkeletonsEndoskeleton• Sponges, echinoderms and

invertebrates• Internal• Calcareous plates in

Echinoderms• Bone, cartilage or both in

vertebrates• Hydrostatic in other

invertebrates

Exoskeleton• Molluscs and arthropods• External• Plates of chitin or CaCO3

The Human Skeleton

• Living tissue• Functions:– Support– Blood production– Mineral storage– Muscle attachment– Protection

The Human Skeleton

• Starts as cartilage models– OSTEOBLAST cells turn the cartilage to bone– Begins in the middle of the bone by forming a

PRIMARY OSSIFICATION CENTER– Same thing begins to happen in the ends of the

bones, forming SECONDARY OSSIFICATION CENTERS

– When the two centers meet, bone growth stops

http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::525::530::/sites/dl/free/0072464631/291136/osteoporosis_final.swf::osteoporosis_final.swf

The Human Skeleton• Bone is remodeled throughout your lifetime– OSTEOCLASTS break down bone and then

OSTEOBLASTS rebuild in weak areas