How do Neurons Communicate

Question 1

neurophysiology

Answer 1

study of chemical and electrical signals in neurons

Question 2

intra-cellular communication

Answer 2

signals travel WITHIN cells/neurons

Question 3

information is received at

Answer 3

dendrites

Question 4

integrated and process at

Answer 4

cell body/axon hillock

Question 5

transmitted/conducted

Answer 5

axon

Question 6

action potential

Answer 6

rapid electrical signal that travels along the axon

Question 7

inter-cellular communication

Answer 7

signals travel BETWEEN cells/neurons

Question 8

neurotransmitter

Answer 8

chemical messenger between neurons
released at synapse

Question 9

membrane

Answer 9

phospholipid bilayer

Question 10

membrane surrounded by

Answer 10

fluid (mostly water) on both sides
intra-cellular fluid/cytosol and extra-cellular fluid

Question 11

lipid

Answer 11

hydrophobic

Question 12

phosphate group

Answer 12

hydrophilic

Question 13

proteins

Answer 13

have both hydrophilic and hydrophobic regions

Question 14

ions are:

Answer 14

charged molecules
(e.g. NaCl dissolves into Na+, Cl-)

Question 15

cation

Answer 15

positive charge

Question 16

anion

Answer 16

negative charge

Question 17

when ions move across the membrane

Answer 17

can generate an electrical signal

Question 18

ions move across the membrane through

Answer 18

ion channels & ion pumps

Question 19

how do ions move across the membrane?

Answer 19

1. diffusion
2. electrostatic pressure

Question 20

diffusion

Answer 20

ions move from regions of high concentration to low concentration (DOWN the concentration gradient)

Question 21

ion concentrations in neurons at rest

Answer 21

higher concentration outside
higher concentration inside
selective ion channels

Question 22

higher concentration outside

Answer 22

cation: Na+, Ca2+
anion: Cl-

Question 23

higher concentration inside

Answer 23

cations: K+
negatively charged proteins

Question 24

At rest, the concentration of Na+ ions is ________ inside the neuron compared to outside the neuron
A. Higher
B. Lower
C. The same

Answer 24

B. Lower

Question 25

electrostatic pressure

Answer 25

ions move across an electric field because they are charged
membrane voltage differential

Question 26

membrane voltage differential

Answer 26

inside of the cell is more negatively-charged than the space immediately outside of the cell

Question 27

opposite charges ______, like charges _______

Answer 27

attract, repel

Question 28

selective ion channels

Answer 28

cations move into cell
anions move out of cell

Question 29

electrochemical gradient

Answer 29

chemical driving force
electrical driving force
these two forces can collaborate (agree) or oppose one another (opposite directions)

Question 30

chemical driving force

Answer 30

concentration

Question 31

electrical driving force

Answer 31

opposite charges attract

Question 32

how are the ion concentration gradients generated/maintained?

Answer 32

sodium-potassium pump
K+ channels

Question 33

sodium-potassium pump

Answer 33

“pump” proteins expend energy to move ions against their gradient
Na+/K+- ATPase pump
moves 3 Na+ ions out and 2 K+ ions in for every energy molecule

Question 34

resting membrane potential (RMP)

Answer 34

rest/resting means in the absence of any other external input
-60 to -70 mV (more negative inside than outside)

Question 35

K+ channels

Answer 35

open (K+ can flow in either direction)
allow positively-charged K+ ions to leave cell down concentration gradient
creates a negative charge inside cell

Question 36

eventually reach equilibrium

Answer 36

chemical and electrical driving forces are equal, but opposite
-60 to -70 mV RMP