Neurophysiology and Action Potentials

The video tutorial by Dr. Inbamalar covers the origin and propagation of biopotentials, which are electrical potentials created by ion flow in cells. It explains resting and action potentials, depolarization, and repolarization, including the role of the sodium-potassium pump. The tutorial also defines key terms like the all-or-nothing law and refractory periods, and provides examples of biopotential signals such as electrocardiograms and electroencephalograms.

What are biopotentials primarily created by?

• The circulation of blood

• The flow of electrons in the body

• The movement of muscles

• The flow of ions in and out of cells

Which ions are primarily involved in maintaining the resting potential of a cell?

• Calcium and magnesium

• Sodium, potassium, and chloride

• Iron and zinc

• Hydrogen and oxygen

What happens to the cell's membrane during an action potential?

• It becomes negatively charged inside

• It allows sodium ions to enter the cell

• It becomes impermeable to all ions

• It releases all potassium ions

What is the approximate potential inside a cell during an action potential?

• +20 millivolts

• -70 millivolts

• 0 millivolts

• +50 millivolts

What process helps the cell return to its resting potential after an action potential?

• Diffusion

• Osmosis

• Sodium-potassium pump

• Active transport of calcium

What is the role of the sodium-potassium pump in repolarization?

• It pumps both sodium and potassium ions out of the cell

• It pumps sodium ions out and potassium ions into the cell

• It pumps potassium ions out of the cell

• It pumps sodium ions into the cell

What does the 'all or nothing law' state about action potentials?

• Action potentials are the same size regardless of the stimulus

• Action potentials occur only if the stimulus is above a certain threshold

• Action potentials vary in size depending on the stimulus

• Action potentials can be partially triggered

Which of the following is an example of a biopotential signal?

• Electrocardiogram

• Body temperature

• Respiratory rate

• Blood pressure reading

What is the absolute refractory period?

• A period when the cell can respond to any stimulus

• A period when the cell cannot respond to any new stimulus

• A period when the cell is hyperactive

• A period when the cell is at rest

Which biopotential signal is generated from the muscles?

• Electrocardiogram

• Electroencephalogram

• Electromyogram

• Electroretinogram