Animated science "Blood" : Blood is a strange fluid, it controls our life. The protein structure of blood enables it to perfom tasks like carrying oxygen to the parts. Our defense systems against infections are carried in blood. This human body animation gives in-depth information about blood, an important component of circulatory system.

Blood, is a fluid pumped by the heart that circulates throughout the body via the arteries, veins, and capillaries. An adult male of average size normally has about 6 quarts (5.5 liters) of blood. The blood carries oxygen and nutrients to the body tissues and removes carbon dioxide and other wastes. The colorless fluid of the blood, or plasma, carries the red and white blood cells, platelets, waste products, and various other cells and substances.

Red blood cells are very small and shaped like tiny doughnuts each contains molecule of a red colored chemical called hemoglobin Red Cells give blood its colour and accounts for up to 40% of its volume. The main function of these cells is to carry oxygen from the lungs to all the cells of the body and remove waste products such as carbon dioxide. Hemoglobin contains the element Iron, making it an excellent vehicle for transporting oxygen and carbon dioxide. As blood passes through the lungs, oxygen molecules attach to the hemoglobin. As the blood passes through the body's tissue, the hemoglobin releases the oxygen to the cells. The empty hemoglobin molecules then bond with the tissue's carbon dioxide or other waste gases, transporting it away.

White blood cells vary in shape because they play a variety of roles when defending against infections
White blood cells only make up about 1 percent of blood, but their small number belies their immense importance. They play a vital role in the body's immune system-the primary defense mechanism against invading bacteria, viruses, fungi, and parasites. They often accomplish this goal through direct attack, which usually involves identifying the invading organism as foreign, attaching to it, and then destroying it. This process is referred to as phagocytosis.

Platelets
The smallest cells in the blood are the platelets, which are designed for a single purpose-to begin the process of coagulation, or forming a clot, whenever a blood vessel is broken. As soon as an artery or vein is injured, the platelets in the area of the injury begin to clump together and stick to the edges of the cut.

Blood clotting (technically "blood coagulation") is the process by which (liquid) blood is transformed into a solid state.
This blood clotting is a complex process involving many clotting factors (incl. calcium ions, enzymes, platelets, damaged tissues) activating each other.

The three stages of this process are:

1. Formation of Prothrombinase

Prothrombinase can be formed in two ways, depending of which of two "systems" or "pathways" apply. These are
Intrinsic System
This is initiated by liquid blood making contact with a foreign surface, i.e. something that is not part of the body; or
Extrinsic System
This is initiated by liquid blood making contact with damaged tissue.
Both the intrinsic and the extrinsic systems involve interactions between coagulation factors. These coagulation factors have individual names but are often referred to by a standardized set of Roman Numerals, e.g. Factor VIII (antihaemophilic factor), Factor IX (Christmas factor).

2. Prothrombin converted into the enzyme Thrombin

Prothrombinase (formed in stage 1.) converts prothrombin, which is a plasma protein that is formed in the liver, into the enzyme thrombin.

3. Fibrinogen (soluble) converted to Fibrin (insoluble)

In turn, thrombin converts fibrinogen (which is also a plasma protein synthesized in the liver) into fibrin.
Fibrin is insoluble and forms the threads that bind the clot

• Peripheral
  
  
•  Nerves- Neuronal Transmission