#9 TpT The Nervous System, Part 2: Crash Course A&P

What is the name of the "Buzz", the signal that a neuron transmits?

• Neuron Signal

• Neuron Message

• Electrical Discharge

• Action Potential

the electric potential across a cell membrane is measured in ______.

• millivolts

• millimeters

• milliwatts

• milliohms

At resting potential the inside of the cell membrane is negatively charged. Why?

• Many positive ions outside (Na+) and (K+); and many negatives inside (proteins).

• More positives outside (Na+) than inside (K+); and more negatives inside (proteins)

• More positives outside (Na+) than inside (K+); and more negatives outside (proteins)

• More positives inside (Na+) than outside (K+); and more negatives outside (proteins)

What allows ions to flow down their electrochemical gradient across the membrane?

• The Sodium-Potassium Pump

• The Phospholipid Bilayer

• Gated Ion Channels

• The Charges of the Ions

To start an action potential moving down the axon, what must happen?

• Equalize the concentrations of Sodium and Potassium across the membrane. (Depolarization) Triggering channels to close.

• Trigger a big enough change in the membrane potential of the neuron body. (Depolarization) Triggering channels to open.

• Increase the negative charge in the neuron cell body. (Polarization) Triggering action of the Sodium-Potassium Pump.

• Transfer enough Potassium out of the neuron. (Repolarization) Triggering a Potassium concentration gradient.

What is the threshold voltage?

• -55 mV

• 0 mV

• -77 mV

• 55 mV

How is repolarization achieved?

• Sodium ions flow in.

• Potassium ions flow in.

• Sodiums ions flow out.

• Potassium ions flow out.

What prevents signals from traveling in both directions down the axon at once?

• Refractory Period

• Repolarization

• Hyper-polarization

• Sodium-Potassium Pump

In what way would neuron signals change from telling a muscle to pick up a piece of paper to telling a muscle to pick up a bowling ball?

• Each signal would last longer.

• Both stronger and more frequent signals would be sent.

• Signals would be sent with higher frequency.

• Stronger signals would be sent.

Which type of neuron conducts impulses faster?

• Myelinated Neurons

• Unmyelinated Neurons