FINAL

• Movement of K+ ions is influenced by which two competing forces?

• A) into cell following concentration gradient, and out of cell following electrical ‘gradient’

• B -Out of cell following concentration gradient, and Into cell following electrical ‘gradient’

What is hyperpolarization?

• Change in membrane potential; it becomes more positive

• Change in membrane potential; it becomes more negative

• Change in membrane potential; it becomes more negative (even more negative than the RMP)

Local (graded) potentials can be excitatory or inhibitory. Action potentials can only be ______.

An ______ postsynaptic potential pushes postsynaptic neuron further away from action potential threshold.

• Which of the following is an example of dual innervation where PSNS and SNS are physiological antagonists?

• Higher SNS activity causes heart rate to increase and higher PSNS activity causes heart rate to decrease.

• Higher PSNS activity causes heart rate to increase and higher SNS activity causes heart rate to decrease.

• The PSNS stimulates the release of a watery saliva whereas the SNS stimulates the release of a more mucus-rich saliva.

• Blood vessels throughout the body are only innervated by the SNS.

What is needed before cross bridge cycling can occur?

• Calcium needs to bind to tropomyosin to move troponin out of the way in order to expose myosin binding sites on actin

• Calcium needs to bind to troponin to move tropomyosin out of the way in order to expose myosin binding sites on actin

• Calcium needs to bind to troponin to move it out of the way in order to expose myosin binding sites on actin

• Calcium must enter the sarcoplasmic reticulum

What does action potential threshold mean?

• Maximum level of depolarization needed for an action potential to occur

• Minimum level of hyperpolarization needed for an action potential to occur

• Minimum level of depolarization needed for an action potential to occur

• The point at which an action potential stops

Draw an action potential graph label

• - Important values

• - make sure you know what each of these values mean ant the signfigance of each value

• - Depolarization

• -Repolarization

• -Hyperpolarization

What is the difference between an action potential and local (graded) potential?

• local potential is when depolarization is occurring but the threshold for an action potential has not been reached

• Local potentials are irreversible, action potentials are reversible

• Local potentials is when depolarization has occured and reached 35-40mv but sodium channels do not close so repolarization can not occur

• Action potentials are for the muscles and local potentials are for the bones

What is a relative refractory period

• The time during which no action potential can be initiated
• The time during which a second action potential can be initiated, but only with a larger-than-normal stimulus.
• The time during which a second action potential can be initiated with a smaller-than-normal stimulus
• The time during which the neuron is completely inactive