The first sound of a cardiac cycle occurs when the _____ and ______ (select them in alphabetical order) are closing. The second sound of a cardicac cycle occurs when the

The first sound of a cardiac cycle occurs when the _____ and ______ (select them in alphabetical order) are closing. The second sound of a cardicac cycle occurs when the  _______ and ________  (select them in alphabetical order)  are closing. Word Options for Blanks: (some may not be used, some may be used more than once) aorta aortic valve bicuspid valve coronary sinus inferior vena cava left atrium left ventricle pulmonary arteries pulmonary trunk pulmonary valve pulmonary veins right atrium right ventricle superior vena cava tricuspid valve