AS Biology Edexcel Topic 1 - structure & function of the mammalian heart

The structure and its relation to the function of the MAMMALIAN HEART:

Cardiac cycle:

• Diastole - heart muscles relax as the atria fill up with blood coming in through the veins (right - inferior/superior vena cava from lower/upper body, left - right/left pulmonary veins from the lungs)
• Atrial systole - Atria contract forcing the atrioventricular valves (right - tricuspid, left - bicuspid) open to allow the blood through into the ventricles
• Ventricular systole - Ventricles contract…