NATS 1675 Lecture 20: The Circulatory System continued / Vascular [Blood] Tissue
Document Summary
Nats 1675 lecture #20 the circulatory system continued / vascular [blood] It is a recording of the electrical changes that occur in the heart during a cardiac cycle. The various peaks and valleys of one cardiac cycle are labeled/indicated by letters: The p-wave indicates that the atria are about to contract; the s-a node has fired . The qrs sequence indicates the ventricles are about to contract; the a-v node has. The t-wave indicates the recovery of the ventricles. It refers to atrial pressure which changes as the heart goes through its cycle. Heart beats/contracts about once in 0. 8 seconds. Contraction phase is referred to as systole. Relaxation phase is referred to as diastole. The sounds the heart makes are described as lub dup (also lubb dupp and lub dub) Lub, the first sound, occurs when increased pressure forces the flaps of the av-valves to close. A swishing sound after the lub indicates a heart murmur or leaky valve.
