NURS 3664 Lecture Notes - Lecture 5: Qrs Complex, Heart Valve, Circulatory System
Document Summary
Structures and functions of cardiovascular system: heart, four chambers, 3 layered wall, endocardium, myocardium, epicardium, pericardium (pericardial sac, left ventricular wall 2-3 times thicker than right. Electrocardiogram: the electrical activity of the heart can be detected on the body surface using electrodes and is recorded on an electrocardiogram (ecg). The letters p, qrs, t, and u are used to identify the separate waveforms: the first wave form, the p wave, begins with the firing of the. Sa node and represents depolarization of the atria: the qrs complex represents depolarization from the av node throughout the ventricles. Purkinje fibers, or it may be associated with hypokalemia. Intervals between these waves (pr, qrs, and qt intervals) reflect the length of time it takes for the signal to travel from one area of the heart to another. These time intervals are measured, and changes from these time references often indicate pathology.
