Neurons - Lecture 1

Question 1

2 ways of communication

Answer 1

Electrical signals and chemical signals

Question 2

Is the electrical potential difference (50 to70 mV) across the cell membrane which result from SEPARATION OF CHARGE. There is more negative charge inside the cell in comparison to exttracellular fluid.

Answer 2

The RESTING MEMBRANE POTENTIAL

Question 3

True or false. The potential outside the cell is defined as zero.

Answer 3

True

Question 4

The RMP is due to :

Answer 4

1. Unequal concentrations of Na ions and K ions inside and outside the cell
2. Unequal permeability of the cell membrane to these ions. ( there are more K+ ions leak channels than Na+)
3. Electrogenic action of the Na-K pump but only affects to a small degree

Question 5

True or false. There are more Na+ inside neurons than K+.

Answer 5

False

Question 6

How are the concentration gradients for k and Na ions maintained?

Answer 6

Through sodium and potassium pump

3 Na+ out and 2 K+ in

Question 7

How is unequal permeability of the cell membrane to different ions including Na+ and K+ explained?

Answer 7

There are two main types of channels which have selective permeability to ions in neurons:
A) Non-gated (leak) channels

Question 8

How does unequal concentration and unequal cell membrane to Na+ and K+ result in a negative RMP?

Answer 8

The concept of the equilibrium potential. More K+ diffuse outside from inside the cell membrane . There will be an increase in negative charge inside.

Question 9

The principal building blocks and instruments of communication in the brain

Answer 9

Neurons