Functions and Membrane Potentials in Excitable Tissues

Dr. Mike explains the concept of resting membrane potential, focusing on excitable tissues like muscles and neurons. He describes how the sodium-potassium ATPase pump and ion channels create a charge difference across cell membranes, leading to a resting potential of -70mV. This potential is crucial for muscle contraction and nerve signal transmission.

What are the primary functions of excitable tissues in the body?

• To produce hormones

• To digest food

• To contract and send electrical impulses

• To store energy

What is the role of the phospholipid bilayer in cells?

• To synthesize proteins

• To produce energy

• To separate the internal and external environments

• To allow all ions to pass freely

Which ions are primarily involved in creating the resting membrane potential?

• Sodium and potassium

• Chloride and phosphate

• Calcium and magnesium

• Hydrogen and oxygen

How does the sodium-potassium ATPase pump affect the cell's charge?

• It makes the inside of the cell more positive

• It makes the outside of the cell more negative

• It has no effect on the cell's charge

• It creates a slightly negative charge inside the cell

What happens when the sodium-potassium pump moves ions across the membrane?

• Three sodium ions are moved inside, and two potassium ions are moved outside

• Two sodium ions are moved outside, and three potassium ions are moved inside

• Three sodium ions are moved outside, and two potassium ions are moved inside

• Two sodium ions are moved inside, and three potassium ions are moved outside

What is the charge difference across the cell membrane due to potassium channels?

• -5 millivolts

• -70 millivolts

• +70 millivolts

• 0 millivolts

What is the typical resting membrane potential in millivolts?

• -5 millivolts

• +70 millivolts

• -70 millivolts

• 0 millivolts

How do leaky potassium channels affect the cell's internal charge?

• They make the inside more positive

• They make the inside more negative

• They have no effect on the charge

• They make the outside more negative

What is the significance of the electrochemical gradient in excitable tissues?

• It allows for potential changes in charge and concentration

• It increases the cell's energy production

• It prevents ion movement

• It stabilizes the cell membrane

Why is the resting membrane potential important for neurons?

• It allows neurons to contract

• It enables neurons to send signals

• It helps neurons to store energy

• It prevents neurons from firing