In closed circulatory system, blood is contained in a closed blood vessel and the blood is distributed to all parts of the body.

Closed circulatory system is found mostly in invertebrates such as insects.

Diagram shows heart of an insect. When the heart contract, it will pump haemolymph into the haemocoel.

Human heart have a complete double circulatory system.

Pulmonary circulation is referring to when blood is pumped to all parts of the body by aorta.

In amphibians, some oxygenated blood is mixed with the deoxygenated blood in the atrium.

Tricuspid valve in human heart ensure blood that flows into left ventricle does not flow back into left atrium.

Plasma protein is one of the blood component and function to carries the oxygen in the cell respiration.

Leucocytes is divided into two types; granulocytes and agranulocytes.

Granulocytes consist of basophil, eusinophyl and neutrophyl while agranulocytes consist of lymphocyte and monocyte.

The wall of an artery is elastic to stop it from breaking due to the high pressured blood that flows through it.

Human heart is made up of myogenic cardiac muscles.

Myogenic refers to heart is unable to contract and relaxed without receiving any impulse from the central nervous system.

The force that enables blood to flows in human is generated from the pumping of the heart and the contraction of skeletal muscles.

The "lub dub" sound during the heart pumping occurs due to the closing of closing of tricuspid/bicuspid valve and the semi-lunar valve.

The blood flows into the artery is assisted by the contraction of smooth and skeletal muscles.

Heparin is an anticoagulants found in the blood to prevent the blood from clotting inside the body.

Blood group A contains Antigen B on red blood cells and Anti A in the blood serum.

The red blood cell of a person with Rh positive, contain Rhesus factor or antigen D.

Artherosclerosis is a type of cardiovascular disease that causes fine arteries to break and the patient can suffer from stroke.

Severe chest pain or angina is caused when the formation and deposition of plaque in the artery walls.

Human blood circulatory system has two types of;open circulatory system and closed circulatory system.