Increasing Excitatory Signals Above the Threshold for a Neuron to Fire

question 252

Multiple Choice

Increasing excitatory signals above the threshold for a neuron to fire will not affect the intensity of an action potential.This indicates that a neuron's reaction

• A)is inhibited by the myelin sheath.
• B)is delayed by a refractory period.
• C)is an all-or-none response.
• D)depends on neurotransmitter molecules.

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Definitions:

Chordae Tendineae

Heart strings, or tendinous cords, that connect the papillary muscles to the tricuspid and mitral valves in the heart.

AV Valves

Atrioventricular valves, which are heart valves located between the atria and ventricles that prevent blood from flowing backward.

Ventricular Systole

The phase of the cardiac cycle during which the ventricles contract, pumping blood out of the heart.

Phagocytosis

The process by which cells, such as immune cells, engulf and digest large particles or microorganisms.