Resting Potential Flashcards
Draw and label the structure of a myelinated motor neurone
includes:
Dendrites
Axon and Axon terminal
Myelin sheath
Schwann cells
Node of Ranvier
nucleus
Where are neurotransmitter chemicals and proteins made in a neurone?
the cell body
What is the role of dentrites?
carry action potential to surrounding cells
What is the axon and what does it do?
long, conductive fibre that carries the nervous impulse along the motor neurone
What are Schwann cells made of?
many layers of myelin sheath
What are the gaps between Schwann cells called?
nodes of Ranvier
What does the myelin sheath do?
prevents charged ions from passing through, it is a lipid so acts as an insulator
What is meant by the term resting potential?
when a neurone is not conducting an impulse, there is a difference between the electrical charge inside the cell and outside
Why is resting potential negative?
as there are more positive ions outside the cell, making the inside comparatively more negative
What co-transport protein is involved in the maintenance of resting potentials?
Na-K pump
How many of each ion are transported each time by the Na-K pump?
2 x K+ INTO the cell
3 x Na+ OUT OF the cell
What does the Na-K pump create?
electrochemical gradient
Why is resting potentially end up negative, if both ions diffuse in/out?
because the membrane is more permeable to K+ ions
Why is the axon membrane more permeable to K+ ions?
- most K+ channels stay open (compared to Na+ ions which only open due to change in voltage)
- there are more K+ channels
How is resting potential maintained?
membrane more permeable to K+ ions and less permeable to Na+ ions
Na+ ions are actively pumped out and K+ ions in
