The frog sciatic nerve gives a graded response because the nerve is a bundle of axons (CAP) and not a single axon (thus it does not show the all or none response of an axon-either generating an action potential or not). Thus the nerve impulse is graded (it can be none, small, medium, large, larger, maximal).Keeping this in view, what was the smallest voltage required to produce the maximum cap?
The smallest voltage to produce the maximum CAP would be . 61 mV. In order to produce the maximal response, you would need all of the nerve fibers to be excited.
Also Know, what other stimulus parameter might also affect the nerve's tendency to generate a cap? Duration as well as frequency can affect the nerve's tendency to generate CAP. Duration can affect a nerves tendency to generate CAP because even a weak signal can generate CAP if it lasts long enough.
Also to know, is the frog sciatic nerve myelinated?
The sciatic nerve of frogs, frequently used in experimental studies, is a mixed nerve composed of myelinated and unmyelinated fibers.
Why the compound action potential is not all or none?
The compound action potential is graded in nature, in striking contrast to the all-or-none response of single axons. Finally, at maximal stimulus strength, every axon in the nerve was contributing its own all-or-none action potential, whence no further increase in the response was possible.
How does a cap differ from a single action potential?
How does a CAP differ from a single action potential? A compound action potential occurs when the nerve is stimulated, while a single action potential refers to the response from a single nerve fiber. The frog sciatic nerve gives a graded response because the nerve is a bundle of axons and not a single axon.What is the relationship between stimulus strength and response amplitude in a single axon?
What is the relationship between stimulus strength and response amplitude in a single axon? According to the all-or-none law, the response a single axon is the same no matter what the stimulus strength is. If the stimulus causes the axon to reach threshold, that axon will complete a full contraction.How many axons are in the sciatic nerve?
Thus, the entire sciatic nerve at midthigh is composed of about 27,000 axons; 6% are myelinated motor axons, 23% and 48% are myelinated and unmyelinated sensory axons, respectively, and 23% are unmyelinated sympathetic axons.What is the diameter of a nerve?
Most individual axons are microscopic in diameter (typically about one micrometer (µm) across). The largest mammalian axons can reach a diameter of up to 20 µm. The squid giant axon, which is specialized to conduct signals very rapidly, is close to 1 millimetre in diameter, the size of a small pencil lead.What is the difference between the absolute and relative refractory period?
Absolute: Is the period of time during which a second action potential ABSOLUTELY cannot be initiated, no matter how large the applied stimulus is. Relative: Is the interval immediately following the Absolute Refractory Period during which initiation of a second action potential is INHIBITED, but not impossible.Why does the amplitude of the compound action potential increase with increasing stimulus strength?
Q: Why does the CAP increase in size and duration with increasing stimulus strength? A: The CAP is the algebraic sum of all individual fibre action potentials of the nerve. As stimulus strength increases, we recruit more fibres, therefore more APs add up to produce a larger bell-shaped curve.What is the cause of the relative refractory period?
The relative refractory period is the interval of time during which a second action potential can be initiated, but initiation will require a greater stimulus than before. Refractory periods are caused by the inactivation gate of the Na+ channel.Why is compound action potential biphasic?
Both the classic intracellular action potential and the compound action potential are biphasic. In other words, they have both positive and negative deflections, but for different reasons. The negative phase of the intracellular action potential is attributed to the mechanism of after-hyperpolarization.What is a threshold stimulus?
The threshold stimulus is the weakest stimulus that could generate an action potential in a neuron.What happens at action potential?
An action potential occurs when a neuron sends information down an axon, away from the cell body. Neuroscientists use other words, such as a "spike" or an "impulse" for the action potential. Action potentials are caused when different ions cross the neuron membrane. A stimulus first causes sodium channels to open.What is an all or nothing response?
All-or-none law. The all-or-none law is the principle that the strength by which a nerve or muscle fibre responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fibre will give a complete response; otherwise, there is no response.What is the amplitude of the compound action potential related to?
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.What is an all or nothing action potential?
An action potential occurs when the membrane depolarises to a certain threshold, if this threshold is not reached the action potential will not be triggered. This is referred to as the all-or-nothing principle in biology: it means that the power of a stimulus is not proportional to the power of the action potential.What is this response to stimulus called?
In physiology, a stimulus (plural stimuli or stimuluses) is a detectable change in the physical or chemical structure of an organism's internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity.What are the four basic parts of a neuron?
A neuron has 4 basic parts: the dendrites, the cell body (also called the "soma"), the axon and the axon terminal.What happens depolarization?
Depolarization occurs when a stimulus reaches a resting neuron. During the depolarization phase, the gated sodium ion channels on the neuron's membrane suddenly open and allow sodium ions (Na+) present outside the membrane to rush into the cell.What is action potential in psychology?
An action potential is part of the process that occurs during the firing of a neuron. During the action potential, part of the neural membrane opens to allow positively charged ions inside the cell and negatively charged ions out. When the charge reaches +40 mv, the impulse is propagated down the nerve fiber. 
