The Aortic semilunar valve

After the aortic semilunar valve closes, there is a brief period where pressure in the aorta is risine This is known as the dicrotic notch What causes this increase in pressure? The building pressure in the atria The buliding pressure in the ventricles

The rebounding of blood against the aortic semilunar valve The closing of the mitral valive Question 29 Which of the following acts as the main pacemaker of the heart and is responsible for sinus riythm?

AV node Purkinje fibers SA node Left bundle branch Question 30 An EKG readout in which a P wave occurs without a subsequent QRS complex is indicative of Heart block Fibrillation Sinus rythym Junctional rythym