Summary and Main Ideas

Summary

• Nutrients and oxygen are required by cells for cellular respiration. These are transported by blood to the various cells.
• Carbon dioxide and other waste products need to be transported from the cells to the exterior. This is also transported via blood.
• There are open and closed circulatory systems. In an open circulatory system blood enters a cavity, in a closed circulatory system blood remains in vessels.
• A double closed circulation system consists of the pulmonary and systemic circulatory systems.
• Blood is pumped through the heart under high pressure to the various parts of the body.
• The right side of the heart receives deoxygenated blood from the body via veins and sends it to the lungs to be oxygenated.
• The left side of the heart receives oxygenated blood from the lungs and sends it via arteries to all parts of the body.
• Specialised cells (sinoatrial node) send signals to the atrioventricular node to cause the atria and ventricles to contact and control the cardiac cycle and heart rate.
• The lymphatic system is composed of lymph vessels, lymph nodes, and organs.
• Lymph vessels assist the circulatory system and all the cells of the body by removing wastes, germs and excess water from the tissue fluid.
• There are many diseases that affect the heart and circulatory system and many treatments are available.