Circulatory system functions

To understand the human circulatory system functions first we have to understand the circulatory system. So here is a short introduction.

Circulatory system

It is also known as the cardiovascular system and it transports the blood and lymph throughout the body to provide nutrients and oxygen to the tissues.

The circulatory system consists of
And lungs.

The lymphatic system is also part of the circulatory system which further consists of an antibody-mediated immune and mediated immune systems.


The heart is pumping organs which have four chambers
Two atria
Two ventricles

Deoxygenated blood comes into the right atrium from where it goes to the right ventricle.

And from the right ventricle, the blood goes into the lungs where it becomes oxygenated and return back to the left atrium.

From the left atrium, the blood passes into the left ventricle and from the left ventricle, the blood passes into the aorta.

Heart receive their blood from the coronary arteries.


Blood is a fluid that has the ability to transport substances. Blood consists of

Red blood cells
White blood cells

Plasma is the fluid portion through which nutrients, hormones, and waste products are transported.

Red blood cells also are known as erythrocytes are produced in the bone marrow. These cells have no nucleus and their cytoplasm contains hemoglobin.

White blood cells also are known as leukocytes are cells that are produced in the bone marrow have clearly defined nuclei.

Platelets are blood fragments and they are also produced in the bone marrow. They have no nuclei.
They play a major role in blood clotting.

Lymphatic system

This system is an extension of the circulatory system which transport lymph.lymph is watery fluid.

The lymphatic system consists of
Lymphatic vessels
Lymph nodes

Circulatory system functions

After understanding the system now it will be easy for you to understand the circulatory system functions. There are a lot of cardiovascular system functions but some of them are

1. It transports oxygen to tissues of the body. The oxygen carrying capacity depends on the partial pressure of oxygen. And due to this partial pressure in the lungs oxygen binds with the hemoglobin and leaves the hemoglobin at the tissue level.

2. It removes carbon dioxide from the tissue. This also depends on the partial pressure due to which in tissues carbon dioxide enters into the blood from where it is transported into the lungs.

3. The plasma of the blood contains nutrients and these nutrients are transported into the tissues to maintain their normal state.

4. There are a lot of glands that are ductless and secrete their secretion into the blood and the blood then transports it into their targeted area.

5. Another important circulatory system functions are transporting white blood cells throughout the body which helps the body in fighting against diseases.

6. WBC contains
Neutrophils. Phagocytic

Eosinophils. Damage to the larval stage of parasites

Basophils. Storage of histamine, immediate hypersensitivity reaction

Monocyte. Phagocytic, cellular, and humoral immunity.

7. Platelets also check endothelial lining for gaps and breaks.

8. Platelets that are present in the blood produce a material which is known as fibrin that creates a web to trap blood cells.

Indirect functions

We called these functions indirect because they are done by the lymphatic system but we include it due to that the lymphatic system is an extension of the circulatory system.

Indirect circulatory system functions are

Transport clean fluids back to the blood
Drain excess fluids from the tissues
Remove debris
Transport fats from the digestive system