Why is action potential biphasic?

The BIPHASIC action potential results from the recording system which uses two surface electrodes of opposite polarity. Electrical stimulation of the nerve gives rise to a compound nerve action potential (CNAP). As it passes the second recording electrode it is deflected in the opposite direction.

Why are we using two pairs of recording electrodes?

In this lab you will study the response of the sciatic nerve of the frog to electrical stimulation using two pairs of stainless steel wire electrodes that are both in contact with the nerve, therefore recording the potential difference between two points on the nerve.

What causes the negative phase of an extracellular recording of a cap?

The negative phase of the extracellular recording is due to the different voltages recorded by two wire recording electrodes, as ions pass through the two electrodes at different time.

How will the action potential at R1 or R2 change as you continue to increase the stimulus voltage?

3. How did the action potential at R1 (or R2) change as you increased the stimulus voltage above the threshold voltage? The action potential didn’t change as the stimulus voltage increased. This is because once threshold is met, the event it all or none, not graded.

What is monophasic and biphasic action potential?

Monophasic Action Potential: To record a monophasic action potential, one of the recording electrodes should be in ECF and the other in ICF. For biphasic action potential recording, both the recording electrodes can be placed either in ECF or ICF.

Why do you suppose the latency differed between the median and lateral fibers?

Terms in this set (38) Earthworm (Lumbricus spp.) Historically, giant axons played an important role in the discovery of: the membrane mechanisms underlying the action potential.

What causes compound action potential?

A compound action potential (CAP) is a signal recorded from a nerve trunk made up of numerous axons. It is the result of summation of many action potentials from the individual axons in the nerve trunk.

What is the usual mode of stimulus transfer in neuron to neuron interactions?

19 Cards in this Set

Excitabilty/Conductivity is the ability to transmit nerve impulses to other neurons	Conductivity
which of the stimuli resulted in the most effective nerve stimulation	chemical
what is the usual mode of stimulus transfer in neuron-to-neuron interactions?	chemical

Why does the compound action potential increase in amplitude with increased voltage?

The evoked compound action potential (ECAP) is the sum of the contributions from all the fibers that respond and so as the stimulation current is increased, more fibers respond, the amplitude grows and (as illustrated in Figure 1) additional peaks appear which are responses from smaller diameter fibers.

Why are fewer action potentials recorded at R2 when TTX is applied between R1 and R2 How well did the results compare with your prediction?

4. Why are fewer action potentials recorded at R2 when TTX is applied between R1 and R2? How well did the results compare with your prediction? TTX blocked the sodium channels, preventing the propagation of the action potential from R1 to R2.

Why were the peak values of the action potential at R2 and R4 the same when you applied a strong stimulus?

Why were peak values of the action potentials at R2 and R4 the same when you applied a strong stimulus? Because action potentials are all-or-nothing.

What does biphasic mean?

having two phases
Biphasic, meaning having two phases, may refer to: Phase (matter), in the physical sciences, a biphasic system, e.g. one involving liquid water and steam. Biphasic sleep, a nap or siesta in addition to the usual sleep episode at night. Phase (pharmacology)