Chapter 3A: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals

Question 1

Polarized

Answer 1

All living cells have an electrical charge that’s more negative on the inside than the outside

Question 2

Resting membrane potential

Answer 2

-65mV

-charged particles are called anions
+ charged particles are called cations

Question 3

Ions are dissolved in…

Answer 3

Fluid

Extracellular fluid: outside the cell

Intracellular fluid: inside the cell

Question 4

Maintaining the membrane potential

Answer 4

Selectively-permeable ion channels
Electrostatic force
Diffusion
Sodium-potassium pump

Question 5

Selectively permeable ion channels

Answer 5

These channels allow specific ions to pass through the cell membrane while blocking others. They are selective based on size, charge, or other properties.

Question 6

Electrostatic forces/electrostatic pressure

Answer 6

If inside of cell is negative, then positive ions on outside are attracted to the inside

Opposite charges attract

Question 7

Diffusion

Answer 7

Tendency of molecules to move from areas of high to low concentration to spread out evenly

Diffusion is the movement of particles (solute)

Question 8

Sodium-potassium pump

Answer 8

It pumps 3 sodium ions for every two potassium ions pumped in
Na+, K+

• Potassium is more highly concentrated inside the cell, so diffusion wants to move them out
• The force of electrostatic pressure draws the potassium back in
• K+ reaches equilibrium potential when the forces moving K+ out of the cell equal the forces pulling them in
  Equilibrium potential: -65mV
• Sodium-potassium pump helps keep all of this in balance