Action Potentials

Multiple Choice

Which ions are primarily responsible for establishing membrane potential in neurons?

• Na+ and K+

• Cl- and Ca2+

• Mg2+ and Ca2+

• H+ and OH-

Labelling

Identify the Concentration Gradient

Drag labels to their correct position on the image

High Concentration

Low Concentration

Multiple Choice

Reflex actions are important because

• They provide a quick, involuntary response

• They prevent injury

• They are essential to the survival of organisms

• All of the above

Multiple Choice

Which of the following statements about membrane excitability is correct?

• It refers to the ability of nerves to carry impulses by creating electric charges.

• It is the process by which potassium ions are pumped out of the cell only.

• It is the ability of membranes to remain at rest indefinitely.

• It is unrelated to sodium and potassium ions.

Multiple Choice

Which of the following best describes the difference between graded potential and action potential?

• Graded potentials are short-lived changes in membrane potential, while action potentials travel faster and are larger.

• Graded potentials travel faster and are larger, while action potentials are short-lived changes in membrane potential.

• Both graded and action potentials travel at the same speed and have the same magnitude.

• Graded potentials always generate a nerve impulse, while action potentials may not.

Multiple Choice

Which ions are primarily involved in the depolarization phase of an action potential?

• Sodium (Na+) ions enter the cell

• Potassium (K+) ions enter the cell

• Sodium (Na+) ions leave the cell

• Potassium (K+) ions leave the cell

Multiple Choice

Which of the following is true about the frequency of action potentials in response to a weak stimulus?

• A weak stimulus triggers less frequent action potentials.

• A weak stimulus triggers more frequent action potentials.

• A weak stimulus has no effect on action potential frequency.

• A weak stimulus always triggers fast reflexes.

Multiple Choice

Which of the following best describes the role of neurotransmitters in impulse transmission across a synapse?

• They transmit impulses by binding to receptors and changing membrane permeability.

• They act as enzymes to break down synapses.

• They form the space between neurons.

• They generate energy for the neuron.

Match

Match the following

• Depolarization

• Repolarization

• Hyperpolarization

• Threshold potential

• Resting potential

cell is getting more +, Na+ in

cell is getting more -, K+ out

cell gets more -, K+ channels close slow

-55 mV

-70 mV

• cell is getting more +, Na+ in

• cell is getting more -, K+ out

• cell gets more -, K+ channels close slow

• -55 mV

• -70 mV

Poll

How do you feel about action potentials?

• Amazing! I got it!

• Okay, will probably go over it on my own

• Meh, need a bit of help and time with the concept

• What is an action potential????