Table of Contents
Which term to the period whereby no neural impulse can be generated even with intense stimulation?
The period immediately following the transmission of an impulse in a nerve or muscle, in which a neuron or muscle cell regains its ability to transmit another impulse, is called the refractory period. During the refractory period, the membrane cannot generate another action potential.
During which period can a second action potential be initiated by a larger than normal stimulus?
relative refractory period
The relative refractory period is a period after one action potential is initiated when it is possible to initiate a second action potential, but only with a greater depolarization than was necessary to initiate the first.
What are the characteristics of impulse conduction?
Impulse conduction – an impulse is simply the movement of action potentials along a nerve cell. Action potentials are localized (only affect a small area of nerve cell membrane). So, when one occurs, only a small area of membrane depolarizes (or ‘reverses’ potential).
How does threshold change during the relative refractory period?
How does threshold change during the relative refractory period? The threshold that must be achieved is higher than the original stimulus intensity during the relative refractory period.
Why is it called relative refractory period?
The cell membrane cannot immediately produce a second AP. As voltage-gated Na+ channels transition from the inactivated to the closed state (i.e., they become capable of being activated), the membrane becomes capable of supporting a 2nd action potential – this period is called the RELATIVE REFRACTORY PERIOD.
What is the refractory period in action potential?
250ms
After an action potential initiates, the cardiac cell is unable to initiate another action potential for some duration of time (which is slightly shorter than the “true” action potential duration). This period of time is referred to as the refractory period, which is 250ms in duration and helps to protect the heart.
What initiates a nerve impulse?
A nerve impulse begins when a neuron receives a chemical stimulus. The nerve impulse travels down the axon membrane as an electrical action potential to the axon terminal. The axon terminal releases neurotransmitters that carry the nerve impulse to the next cell.
What is an impulse describe the physiology of impulse conduction?
A nerve impulse is the electric signals that pass along the dendrites to generate a nerve impulse or an action potential. Conduction of nerve impulse occurs due to the presence of active and electronic potentials along the conductors. Transmission of signals internally between the cells is achieved through a synapse.
What is relative refractory period?
Medical Definition of relative refractory period : the period shortly after the firing of a nerve fiber when partial repolarization has occurred and a greater than normal stimulus can stimulate a second response — compare absolute refractory period.
What is parasympathetic and sympathetic?
The autonomic nervous system comprises two parts- the sympathetic and parasympathetic nervous system. The sympathetic nervous system activates the fight or flight response during a threat or perceived danger, and the parasympathetic nervous system restores the body to a state of calm.