Transportation system define with digram

Transportation in Human Beings:

Blood is a red coloured liquid which circulates in our body. It is red because it contains a pigment called haemoglobin in its red cells.

Our Pump – the heart:

The heart is roughly triangular in shape. It has four compartments called chambers inside it. The upper two chambers of the heart are called atria and the lower two chambers are called ventricles. The atria receive blood from the two main veins. The left atrium is connected to the left ventricle through a valve V1 and the right atrium is connected to the right ventricle through another valve V2. These valves prevent the backflow of blood into atria when the ventricles contract to pump blood out of the heart to the rest of the body because when the ventricles contract, the valves V1 and V2 close automatically so that the blood may not go back into the atria. The job of heart is to pump blood around our body. All the atria and ventricles of the heart contract and relax at appropriate times and make the heart behave like a pump. A sheath of tissue called pericardium protects the muscular heart.

Blood vessels:

Arteries are the vessels which carry blood away from the heart to various organs of the body. Since the blood emerges from the heart under high pressure, the arteries have thick, elastic walls. Veins collect the blood from different organs and bring it back to the heart. They do not need thick walls because the blood is no longer under pressure, instead they have valves that ensure that the blood flows only in one direction. On reaching an organ or tissue, the artery divides into smaller and smaller vessels to bring the blood in contact with all the individual cells, called capillaries.

Lymphatic system:

A system of tiny tubes called lymph vessels (lymphatics) and lymph nodes (lymph glands) in the human body which transports the liquid called lymph from the body tissues to the blood circulatory system is called lymphatic system.