Tag Info

New answers tagged

1

The concentration of K+ inside the cell is 30 time more than outside. Hypoxia causes loss of this intracellular Kalium and consequent/premature repolarization when measuring the potential of action. As the all the ECG theory is Vector based, any abnormality in the electric pathways and myocytes will result in changes of ECG. This picture depicts the ST ...


3

In Wolff-Parkinson-White syndrome, the normal Q wave is usually masked by the preexcitation action potential which produces the delta wave. Despite this, missing Q wave is not a diagnosis criteria of the syndrome, and up to 70 percent of the patients show a negative delta wave which causes differential diagnosis problems because it is confused with Q, ...


1

Short answer SSVEP frequency corresponds to stimulus frequency and SSVEP amplitude decreases with stimulus frequency. Background The simplest form of steady state visual-evoked potentials (SSVEPs) are those to flash stimuli. Herrmann (2001) studied the SSVEP by recording the EEG from the visual cortex at various flash frequencies. He found that SSVEPs ...


2

This is the figure OP talks about: Negative Conductance Caused by Entry of Sodium and Cesium Ions into the Potassium Channels of Squid Axons, Francisco Bezanill, Clay M. Armstrong (1972). Short answer is that in non-linear mode of ion channel operation other ions start passing through it (channel loses specificity). Cumulative effect (because of ...


2

The only abnormality which can be seen on the ECG curve is a prolonged PR Interval but only when acute alcohol poisoning has been done. In the referenced paper the patient had consumed 3.7 g/l (3.7 per mille) which resulted in a PR prolongation of 200-300 ms. The normal PR interval is different for everybody but it normally is 0.12 to 0.20 seconds. A long ...


6

The pacemaker potential is interesting (to a biologist) as it involves your typical Na/K channels, Ca channel, as well as a funny current (If) or alternatively called hyperpolarization-activated current. The funny current is a mixed sodium-potassium current that activates upon hyperpolarization at voltages in the diastolic range (normally from ...



Top 50 recent answers are included