What is Circulatory System in the Body?

Our body has special systems and complicated mechanism which ensure proper functioning of all the internal organs as well as different body parts. One of the very important systems is the circulatory system that is also known by the cardiovascular system or the vascular system.

The meaning of cardiovascular word in Latin refers to ‘heart’ and ‘vessel’. As the name circulatory system suggests, it is a process of transporting vital substances throughout the body. The circulatory system has two mechanisms, a systemic circulation and a pulmonary circulation. The lymphatic system and the cardiovascular system are often called the body's two circulatory systems.

How does Circulatory System Work in the Body?

It is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.

Different Components of the Circulatory System Comprise the Following:

1. The Heart, Blood and Blood Vessels

a) Heart: The heart is an important well-developed organ in the circulatory system, which is located behind but slightly to the left side of breastbone. It is the key organ like a hollow, muscular pump (or two pumps in one) that propels blood throughout the body. The right side of the heart receives blood from the body and pumps it to the lungs. It usually beats from 60 to 100 times per minute, but can go much faster when necessary.

b) Blood: It is a fluid consisting of plasma, red blood cells, white blood cells, and platelets that is circulated by the heart through the vertebrate vascular system. The blood provides the body with the oxygen and nutrients it needs. It also carries away materials from all the body tissues.

c) Blood Vessels: This circulatory system consists of a network of blood vessels such as arteries, veins and capillaries. These blood vessels carry blood to and from all areas of the body.

2. The Lymphatic System

The lymph, lymph nodes, and lymph vessels constitutes the lymphatic system. This system is an important part of the immune system, the body's defense system against disease. It is an open system providing an accessory route for excess filtered blood plasma from the interstitial fluid (between cells) as lymph to be returned to the blood.

Different Components of the Lymphatic System Comprise the Following:

a) Lymph: Lymph is basically recycled excess blood plasma cell. It is colourless fluid containing white blood cells, which bathes the tissues and drains through the lymphatic system into the bloodstream.

b) Lymph Nodes: These are small bean-shaped glands which are part of the lymphatic system. Lymph nodes carry fluid (lymph fluid), nutrients, and waste material between the body tissues and the bloodstream.

c) Lymph Vessels: Lymphatic vessels (or lymph vessels or lymphatics) are thin-walled, valved structures that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system.

Lymph vessels are lined by endothelial cells and have a thin layer of smooth muscles and adventitia that bind the lymph vessels to the surrounding tissue. Valves are found in larger lymph vessels and collecting vessels and are absent in the lymphatic capillaries. The valves is to prevent backflow of fluid.

There are two lymph channels in the body—the right lymphatic duct and the thoracic duct. The right lymphatic duct drains lymph from the right upper limb, right side of thorax and right halves of head and neck.