Medical Definition of orthodromic 1 : proceeding or conducting in a normal direction —used especially of a nerve impulse or fiber orthodromic neural stimulation.

What is the orthodromic conduction?

Orthodromic, therefore, means conducting impulses in the normal or correct direction. Orthodromic denotes the propagation of an impulse along a conduction system (for example, nerve fiber) in the direction it normally travels.

What is orthodromic and Antidromic conduction?

In an orthodromic study, the recording electrodes measure the action potential traveling in the physiologic direction. In an antidromic study, the recording electrodes measure the action potential traveling opposite the physiologic direction.

What is orthodromic impulse?

An orthodromic impulse runs along an axon in its anterograde direction, away from the soma. In the heart, orthodromic may also refer to an impulse going in the correct direction from the dendrites to axon terminal (from the atria to the ventricles) in contrast to some impulses in re-entry.

What is the definition Antidromic?

: proceeding or conducting in a direction opposite to the usual one —used especially of a nerve impulse or fiber.

What does orthodromic mean?

16 related questions found

What is orthodromic AVRT?

Orthodromic AVRT means that the ventricles are depolarized normally via the atrioventricular node and His-Purkinje system (Figure 3). Because the impulse reaches the ventricles through the His-Purkinje network the QRS complexes will appear normal (i.e QRS duration will be <0.12 s).

What is compound action potential amplitude?

The amplitude of the recorded compound action potential is a summation of the individual action potentials from the different axons. When the waves pass the recording site in phase they add constructively and display a higher peak.

What is antidromic action potential?

An antidromic impulse in an axon refers to conduction opposite of the normal (orthodromic) direction. ... For most neurons, their dendrites, soma, or axons are depolarized forming an action potential that moves from the starting point of the depolarization (near the cell body) along the axons of the neuron (orthodromic).

What is an action potential?

The action potential is an explosion of electrical activity that is created by a depolarizing current. This means that some event (a stimulus) causes the resting potential to move toward 0 mV. When the depolarization reaches about -55 mV a neuron will fire an action potential. This is the threshold.

What are Ranvier's nodes?

node of Ranvier, periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. ... Nodes of Ranvier are approximately 1 μm wide and expose the neuron membrane to the external environment.

What is Saltatory conduction?

Saltatory conduction describes the way an electrical impulse skips from node to node down the full length of an axon, speeding the arrival of the impulse at the nerve terminal in comparison with the slower continuous progression of depolarization spreading down an unmyelinated axon.

What decreases nerve conduction velocity?

Temperature. In general, the conduction velocities of most motor and sensory nerves are positively and linearly associated with body temperature (low temperatures slow nerve conduction velocity and higher temperatures increase conduction velocity).

What is an F wave in nerve conduction?

The F-wave is a long latency muscle action potential seen after supramaximal stimulation to a nerve. ... It is generally accepted that the F-wave is elicited when the stimulus travels antidromically along the motor fibers and reaches the anterior horn cell at a critical time to depolarize it.

What does Nondecremental mean?

the propagation of a nerve impulse along an axon in which the amplitude of the impulse is maintained as it progresses. Compare decremental conduction.

Are neuron cells?

A neuron or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. It is the main component of nervous tissue in all animals except sponges and placozoa. ... A typical neuron consists of a cell body (soma), dendrites, and a single axon.

Where in a neuron does Saltatory conduction take place?

Although the action potential appears to jump along the axon, this phenomenon is actually just the rapid, almost instantaneous, conduction of the signal inside the myelinated portion of the axon.

What is action potential example?

For example, say you want to pick up a glass so you can take a drink of water. The action potential plays a key role in carrying that message from the brain to the hand.

What is repolarization in action potential?

Repolarization is a stage of an action potential in which the cell experiences a decrease of voltage due to the efflux of potassium (K⁺) ions along its electrochemical gradient. This phase occurs after the cell reaches its highest voltage from depolarization.

What is monophasic action potential?

The monophasic action potential (MAP) is a near replica of the transmembrane potential recorded when an electrode is pushed firmly against cardiac tissue. ... The network is formed by the interaction between the passive tissue properties and the double-layer capacitance of electrodes.

What is antidromic propagation?

The antidromic propagation of a spike refers to its conduction in a direction opposite from the normal (orthodromic) direction (away from axon terminals to soma instead of propagating from the initial segment of the axon, close to the soma, toward axon terminals).

Where does refractory period occur?

The relative refractory period is the period that occurs during the undershoot phase; where an action potential can be activated but only if the trigger (stimulus) is large enough.

Do you obtain an action potential if the impulse is antidromic?

(2009) have concluded that reliable action potentials can be obtained in antidromic recordings at 25% of the stimulus intensity that would generate a maximal response.

What is the stimulus artifact?

The stimulus artifact is present whether or not the nerve is in the tube, though its form may be altered by the electrical properties of the nerve. It is called an artifact because it is a product of human intervention and is not produced by the nerve.

What is cap amplitude?

The peak amplitude of the CAP is the voltage value of the peak of the CAP response. The latency of the onset of the CAP is the time from the onset of the stimulus artifact to the onset of the CAP. The latency of the peak of the CAP is the time from the onset of the stimulus artifact to the peak of the CAP.

What is Chronaxie and Rheobase?

Chronaxie is the minimum time required for an electric current double the strength of the rheobase to stimulate a muscle or a neuron. Rheobase is the lowest intensity with indefinite pulse duration which just stimulated muscles or nerves.