Action Potentials Are Described as Being 'All-Or-None

question 21

Multiple Choice

Action potentials are described as being 'all-or-none'. This property means that ______.

• A) action potentials do not vary in size dependent upon the size of the stimulus
• B) an axon can only fire one action potential at a time
• C) for an action potential to be triggered all of the sodium channels in the membrane need to open
• D) if a sensory neuron experiences a stimulus below the threshold potential it will produce a small action potential

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Definitions:

Rubbery

A term often used in medicine to describe a consistency of tissue that is flexible yet resistant, similar to the feel of rubber.

Fixed

A term that describes something that is securely attached, unchanging, or incapable of being altered.

Fontanels

Soft spots on an infant's skull that allows for growth of the head during the first year.

Tonic Neck Reflex

An infant reflex where turning the head to one side causes the arm on that side to stretch out and the opposite arm to bend at the elbow.