neurophysiology Neurophysiology is a branch of physiology and neuroscience concerned with the functions of the nervous system and their mechanisms. The term ''neurophysiology'' originates from the Greek word ''νεῦρον'' ("nerve") and ''physiology'' (whic ...

, the Compound action potential (or CAP) refers to various

evoked potential An evoked potential or evoked response is an electrical potential in a specific pattern recorded from a specific part of the nervous system, especially the brain, of a human or other animals following presentation of a stimulus such as a light fl ...

s representing the summation of synchronized individual

action potential An action potential (also known as a nerve impulse or "spike" when in a neuron) is a series of quick changes in voltage across a cell membrane. An action potential occurs when the membrane potential of a specific Cell (biology), cell rapidly ri ...

s generated by a group of

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

s or

muscle fiber A muscle cell, also known as a myocyte, is a mature contractile cell in the muscle of an animal. In humans and other vertebrates there are three types: skeletal, smooth, and cardiac (cardiomyocytes). A skeletal muscle cell is long and threadl ...

s in response to a stimulus. Alike individual action potentials, CAP waveforms are typically biphasic presenting a negative and positive peak. The morphological attributes of the CAP (amplitude, spread, latency) depend on various factors including electrode placement, stimulus intensity, number of fibers recruited, the synchronization of action potentials, and conduction properties of the neural or muscular fibers. In most occurrences, the CAP refers to: * the auditory compound action potential (CAP), generated by the

auditory nerve The cochlear nerve (also auditory nerve or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve. The cochlear nerve carries auditory sensory information ...

, or * the

compound muscle action potential The compound muscle action potential (CMAP) or compound motor action potential is an electrodiagnostic medicine investigation (electrical study of muscle function). The CMAP idealizes the summation of a group of almost simultaneous action potentia ...

(CMAP)

References

{{reflist Neurophysiology Action potentials