Quiz 226

Question 1

Irritability-

Answer 1

Ability of organisms to respond to stimulation

Question 2

Neurons-

Answer 2

cells that specialize in collection, conduction, and transmission of information via electrical impulses.

Question 3

Nucleus- in __________ ( __________ center of cell, where __________ __________ __________)

Answer 3

cell body, metabolic, contents are manufactured

Question 4

Dendrites-

Answer 4

receive info

Question 5

Axon-

Answer 5

sends out info

Question 6

Terminal knob-

Answer 6

ends of axons where impulses are transmitted to target cells

Question 7

Myelin sheath- Increases __________ because of its ________________ composition. __________ are almost all in unwrapped gaps, which is where ___________ are generated. Chain reaction w/o having to _______ each membrane. Impulse chain reaction is called ____________- VERY fast

Answer 7

conduction velocity, lipid membrane, na+ ions, action potentials, activate, saltatory conduction

Question 8

When hippocampal neurons repeatedly stimulated, connections become _________. Very involved in _________

Answer 8

stronger, learning

Question 9

Neurotransmitters eliminated either by _________ or by _________________________________

Answer 9

enzymes, proteins that take them back to presymaptic terminal

Question 10

Voltage/electric potential difference- Difference in concentration of __________ across points (Happens because of ______________-)
+ ions leaving means ___________ where they were

Answer 10

positive/negative ions, ion pumps, na/k, - charge

Question 11

Axon resting potential

Answer 11

-70 mv

Question 12

When acons are stimulated- mechanically or electrically- some _______________ open, which lets _______________ into the cell. Reduces _____________, mmakes it more _______. (Makes cell less polar, so it’s ______________)

Answer 12

soduum channels, sodium, membrane potential, positive, depolarization

Question 13

If ti pases the threshold __________- , _____________ open. ____________ diffuse into cell a lot, cell briefly reverses membrane potential because cell becomes positive at about _____. Close to eq potential at na+, closes when inactivation peptide blocks opening like K+ channels
___________- move out to balance changes in sodium, membrane goes back to _______, close to K+ eq potential. ________ charge makes channels close, bringing membrane to resting state. TOTAL PROCESSES NAME- __________

Answer 13

(~-50 mV), voltage gated channels, Sodium ions, 40 mv, K+ Ions, -80mV, negative, Action potential

Question 14

CHANGES in membrane potential are NOT caused by concentration changes, but the

Answer 14

MOVEMENTS OF CHARGED PARTICLES!

Question 15

All or none law-

Answer 15

Greater or equal to threshold stimulation triggers an action potential, sub won’t do anything. Energy to create it is stored by Na/K ATPase.

Question 16

Action potentials progress as _________down the length of the cell to __________. Reactions are so powerful they can create successive _____________, which creates many action potentials. However, all impulses same strength- so stronger stimuli doesn’t produce bigger impulses. Differences in intensity are ____________

Answer 16

nerve impulses, terminals, adjacent reactions, frequency

Question 17

Synapses-

Answer 17

junctions where neurons are linked with target cells

Question 18

Synaptic cleft- =

Answer 18

gap between cells and junctions

Question 19

Steps:
When an impulse reaches a terminal knob (step 1, Figure 4.57), the accompanying depolarization induces _______________________ in the ________ of this part of the _________ (step 2, Figure 4.57). Calcium ions are normally present at __________ concentration within the neuron (about 100 nM), as in all cells. When the gates open, calcium ions diffuse from the _____________ into the ____________, causing the [Ca2+] to ______ more than a thousandfold within localized microdomains near the channels. The elevated [Ca2+] triggers the rapid fusion of one or a few nearby ___________ with the plasma membrane, causing the release of _________________ into the synaptic cleft (step 3, Figure 4.57).

Answer 19

the opening of a number of voltage-gated Ca2+ channels, plasma membrane, presynaptic nerve cell, very low, extracellular fluid, terminal knob of the neuron, rise, synaptic vesicles ,neurotransmitter molecules

Question 20

When stuff binds to receptors- it can trigger ___________ and influx of ________/(opposite with potassim), depending on what the cell needs. Can excite or relax cell (excites with ___________)

Answer 20

opening of cation selective channels, sodium, cations

Question 21

Resting potential-

Answer 21

unexcited state

Question 22

Presynaptic cell- receptor/neuron sends impulses towards a ______________, where a postsynaptic (neuron, muscle, gland) cell receives them. This happens because pre cells have post cells have ________________________________

Answer 22

synapse, vesibles for chemical transmitters.

Question 23

All terminal knobs in one neuron release _________neurotrans. Effect depends on _________

Answer 23

same, type of cell