Question

What is a circulatory system?

Answer 1

Hint: Circulatory system is an important system in our body whose role is to circulate essential ions, nutrients etc to all the parts of our body. It is also known as the cardiovascular system or vascular system. Different organisms have different kinds of circulatory systems depending on their needs.

Complete answer:
The circulatory system helps in the transport and circulation of carbon dioxide, oxygen and nutrients to all the parts of the body. It is a system that comprises the heart, lungs and blood vessels-arteries and veins.

The circulatory system is of two types-
- Open circulatory system: It is the system found in the invertebrates. In this, the body fluid flows in the cavities and the blood vessels are not required for circulating blood.
- Closed circulatory system: In this system, the heart is present which is the pumping organ that pumps blood into the vessels that reach the tissues and organs. The exchange of gases takes place between the capillaries and the tissues as in the case of human beings and other animals.

In humans, the heart is the pumping organ that receives deoxygenated blood from the body through veins, sends it to the lungs from oxygenation and supplies the oxygenated blood to all the parts of the body through arteries. There occur two types of circulation- systemic in which the blood is supplied and received from all the parts of the body and pulmonary in which the blood is sent and received from the lungs for oxygenation.

Note: Human heart is a four-chambered heart that comprises two upper auricles and two ventricles. It does not involve the mixing of the oxygenated and deoxygenated blood. In the case of reptiles, they have three-chambered hearts: two auricles and one ventricle. This is because they can also exchange oxygen through their skin.