[Science Form 3] About Blood

The transport system in humans is called the circulatory system, which is made up of heart and blood vessels.

The functions of the blood circulatory system are to:

• supply oxygen to all body cells and eliminate carbon dioxide,
• transport waste products

Structure of the heart

Oxygen-rich blood (red color)

Oxygen-poor blood (blue color)

• AO = Aorta
• LA = Left atrium
• LV = Left ventricle
• PA = Pulmonary artery
• RA = Right atrium
• RV = Right ventricle

The heart is a muscular structure that contracts in a rhythmic pattern to pump blood. It si the size of your fist and has four chambers:

• right atrium
• right ventricle
• left atrium
• left ventricle

The space in the atrium is smaller than that in the ventricle. The wall of the ventricle is thicker and stronger than that of the atrium.

Valve TRICUSPID - Prevents blood in the right ventricle from flowing back to the right atrium.

Valve BICUSPID - Prevents blood leaving the heart from flowing back.