The endocrine component of the pancreas consists of islet cells (islets of Langerhans) that create and release important hormones directly into the bloodstream. Two of the main pancreatic hormones are insulin, which acts to lower blood sugar, and glucagon, which acts to raise blood sugar.
Variability is a measure of the spread of a data set. Learn more about the different measures of variability including the range, variance, and standard deviation, and how they are used in the field of Psychology.
Heart rate variability. Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include: cycle length variability, RR variability (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and heart period variability.