[Week 3] Neurons

Question 1

Action potential

Answer 1

electrical current conducted down the axon when membrane potential reaches threshold of excitation

Question 2

Axon

Answer 2

carries impulses AWAY from the cell body to other neurons

Question 3

Cell membrane

Answer 3

A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.

Question 4

Dendrite

Answer 4

carry neural impulses TO the cell body

Question 5

Diffusion

Answer 5

The force on molecules to move from areas of high concentration to areas of low concentration.

Question 6

Electrostatic pressure

Answer 6

The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.

Question 7

Excitatory postsynaptic potentials

Answer 7

A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.

Question 8

Inhibitory postsynaptic potentials

Answer 8

A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.

Question 9

Ion channels

Answer 9

Proteins that span the cell membrane

Question 10

Ionotropic receptor

Answer 10

Ion channel that opens to allow ions to permeate the cell membrane under specific conditions

Question 11

Myelin sheath

Answer 11

fatty tissue composed of glial cells that insulates the axon; facilitates faster communication between neurons

Question 12

Neurotransmitters

Answer 12

chemical messengers stored in neuron that activate receptors of other neurons

Question 13

Nucleus

Answer 13

Collection of nerve cells found in the brain which typically serve a specific function.

Question 14

Resting membrane potential

Answer 14

The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).

Question 15

Sodium-potassium pump

Answer 15

An ion channel that uses the neuron’s energy (adenosine triphosphate

Question 16

Soma

Answer 16

Cell body of a neuron that contains the nucleus and genetic information; “powerhouse of the neuron”

Question 17

Spines

Answer 17

Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.

Question 18

Synapse

Answer 18

space between axon tip of neuron sending message and dendrite of neuron receiving message

Question 19

Synaptic gap

Answer 19

Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine

Question 20

Synaptic vesicles

Answer 20

Groups of neurotransmitters packaged together and located within the terminal button.

Question 21

Terminal button

Answer 21

end of axon; forms synapses with postsynaptic dendrites; discharges and recycles neurotransmitters

Question 22

Threshold of excitation

Answer 22

Specific membrane potential that the neuron must reach to initiate an action potential.