Relative to the electrical events (depolarization/repolarization of atria/ventricles) AND the mechanical events (contraction/relaxation of ventricles/atria) of the cardiac cycle, what do the following measurements represent? a. R-wave to Ist sound b. R-wave to 2nd sound c. 2nd sound to next 1st sound . ENDOCRINE ACTIVITY (20pts) 1. What type of cell communication is described by each of the examples? (3pts) When cells are injured, they releases cytokines, which triggers inflammation in the local area: The adrenal cortex releases cortisol, which travels through the blood to the liver and causes glycogen hydrolysis To slow down the heart rate, parasympathetic neurons release the neurotransmitter acetylcholine to the pacemaker cells of the heart
