Neurones And Resting potential

Question 1

What does the CNS consist of?

Answer 1

The brain and the spinal cord

Question 2

What does the PNS consist of?

Answer 2

The spinal and cranial nerves outside of the CNS

Question 3

What is a neurone?

Answer 3

a specialized cell transmitting nerve impulses; a nerve cell.

Question 4

How many neurones are there in the average brain?

Answer 4

Approximately 100 billion

Question 5

What is an ion?

Answer 5

Charged particles that are important for determining the difference in electrical charge between the inside and outside of all cells

Question 6

What is the name of the thin plasma membrane that surrounds neurones?

Answer 6

Neurolemma

Question 7

What is the resting membrane potential of a neurone?

Answer 7

-70mv

Neurone is polarised

Inside of neurolemma is negatively charged

Question 8

What is an action potential?

Answer 8

Transient reversal of the membrane potential (depolarisation)

Question 9

What are cations and anions?

Answer 9

Cations: ions with positive charge
Anions: ions with negative charge

Question 10

What are the effects of sodium on the resting membrane potential?

Answer 10

• More highly concentrated on the outside of neurolemma
• Membrane is fairly impermeable to sodium ions
• Electrostatic and diffusion forces pushing them in so a few ‘leak’ into the neurone

Question 11

What are the effects of potassium on the resting membrane potential?

Answer 11

• More highly concentrated on the inside of the neurolemma
• Membrane is fairly permeable to potassium ions
• A little net diffusion pushes them out so a few ‘leak’ out of the neurone

Question 12

What are the effects of Chlorine on the resting membrane potential?

Answer 12

• More highly concentrated on the outside
• Membrane is fairly permeable to chlorine ions
• Electrostatic and diffusion forces balance out so little net movement