Human Circulatory System Transportation


Blood travels through the body's arteries, veins, and nerves. Throughout your body, it is responsible for transporting oxygen, nutrients, and waste products. Circulatory system components include the heart, arteries, veins, and blood itself.

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Features of Circulatory System

The circulatory system−the system of blood vessels that transport blood throughout the body−is a network of vessels that begins in the heart and ends in blood capillaries. It is a closed-loop system, which means that it has no opening to the outside environment, so all of the materials it transports are contained within it. The circulatory system consists of two parts− the cardiovascular system, which is made up of the heart and blood vessels, and the lymphatic system, which is composed of lymph ducts and lymph nodes.

It begins with two atria (or auricles) and one ventricle (or ventriculus), which make up the heart. Blood flows through each atrium into its corresponding ventricle, where it is then pumped out into circulation via the major arteries. Blood can flow to any part of your body through a network of smaller arteries, arterioles, capillaries, and venules that branch off from the larger arteries. From here, it delivers nutrients to cells and then returns to the heart as venous blood via veins.

Diseases or disorders that affect this system can be fatal if not treated immediately.

Organs of the circulatory system

The circulatory system is both the most important and most complex of all the body's systems. It delivers oxygen and a wide variety of nutrients to every cell in your body, as well as carrying away carbon dioxide and other wastes. The circulatory system also plays a central role in temperature regulation by continually carrying heat from your warm-blooded centre (your heart, your arteries, and your muscles) to the slightly cooler skin on the rest of your body.


A pumping heart and an anatomical heart are the two sorts of hearts that can exist in the human body. The two upper atria take in blood from the body, the two lower ventricles circulate it to various organs, and there are four chambers in the heart. The atria contract, allowing blood to enter the ventricles. The heart's ventricles contract, causing the blood to be pumped out.

The four chambers of the heart are kept open by heart valves, which ensure that blood flows only in one direction. Blood flows from one chamber into another through an opening called an ostium (plural− ostia). The opening between each atrium and ventricle is called an atrioventricular valve (AV valve), and the opening between each ventricle and main artery is called a semilunar valve (also known as a pulmonary valve).

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Double Circulation

The heart has two separate blood supply systems− pulmonary circulation and systemic circulation. The two circulations are separated by the lungs, which filter out carbon dioxide and recirculate oxygen.

Renal veins and pulmonary vessels transport deoxygenated blood from the body's different regions. At this point, carbon dioxide is released into alveoli while oxygen diffuses into red blood cells. This process is called double circulation because it allows oxygenated blood to be pumped around one circuit while deoxygenated blood is pumped around another circuit before returning for another round of oxygenation.


Blood is the body's liquid connective tissue. It carries oxygen and nutrients to cells and removes waste products from them.

Blood consists of plasma, formed by water and dissolved proteins, blood cells (red blood cells, white blood cells, and platelets), and other components. The volume of blood in a healthy adult male is about 5 litres; it makes up 7% of total body weight.

The red blood cell count is normally about 4.7 million/microliter of blood. White blood cells are produced in the bone marrow, and their number varies according to health status. Platelets circulate through the body's bloodstream, ready to help stop bleeding at the site of injury or disease.

Blood Vessels

Blood vessels are the arteries and veins that carry blood throughout the body. The term "blood vessels" refers to the arteries and veins that carry blood throughout the body. Blood vessels are the conduits through which blood moves from the heart to the rest of the body. Circulating blood travels through a variety of blood vessels.

Blood is carried away from the heart through arteries. They have robust walls that can tolerate high pressure and contain oxygen-rich blood. Smooth muscles in the walls of arteries also help adjust the diameter of the artery and hence control blood flow.

Veins are vessels that return blood to the heart. They contain oxygen-depleted blood and have thin walls so they can easily expand and contract as they move blood towards the heart.

Capillaries are microscopic tubes that connect arteries with veins. The capillaries exchange oxygen from arteries with carbon dioxide from veins, enabling gas exchange between the bloodstream and tissues of the body. Capillaries also help regulate body temperature by controlling how much heat is transferred from arterial to venous blood as it passes through them.

Lymphatic vessels transport lymph, a clear fluid containing immune cells called lymphocytes (also known as white cells). Lymph collects around tissues in order to remove waste products such as excess water, salt, or fat which may have leaked out of damaged cells (lymphocytes).

Lymphatic System

The lymphatic system is a network of ducts, vessels, and organs that transport lymph, a colourless fluid containing immune cells, throughout the body. Lymph is formed when blood passes through the thin walls of smaller arteries and veins as it flows through tissues. The lymphatic system includes−

Lymph nodes − bean-sized collections of tissue that filter foreign particles and bacteria from the lymph. The nodes can swell or shrink in response to disease or infection.

Lymph vessels − thin-walled tubes that carry lymph away from the nodes toward larger vessels called thoracic ducts. These vessels also carry fat cells.

Thoracic ducts − large tubes that carry lymph from the upper body (neck, chest, and back) to the left subclavian vein near your heart.

Spleen − an organ inside your abdomen where white blood cells are made and stored until they're needed by your immune system. The spleen filters out old red blood cells and platelets when they're no longer needed by your body (this process is called "lymphocytopoiesis").

Functions of Circulatory System

The heart and blood arteries make up the circulatory system. The heart pumps blood through the body's arteries like a pump. Cells receive oxygen and nutrients from the blood, which then go to capillaries. Carbon dioxide and waste products are delivered back to the heart by veins in the returning blood.

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There are two primary functions of the circulatory system− delivering oxygen and nutrients to the cells and removing waste products from the cells. By dispersing heat through the skin's blood vessels, it helps to keep the body at a comfortable temperature.


The circulatory system is responsible for the transportation of blood, nutrients, and oxygen to different parts of the body. It is a complex system that is made up of the heart, blood vessels, and blood. The circulatory system is vital to the overall health of the body and plays a crucial role in keeping the body functioning properly.


1. What is the human circulatory system?

The human circulatory system is a network of blood vessels that carry blood throughout the body.

2. How does the heart move the blood?

Because it's a muscle, the heart goes through phases of contraction and relaxation. The pulmonary artery delivers oxygen-rich blood to the left side of your heart. The aorta is responsible for distributing this blood to the rest of your body. As blood circulates about your body, it is collected by veins and sent back to the lungs through your heart's right ventricle, where it can be oxygenated. Until you die, your blood is always being exchanged between the oxygenated and deoxygenated states.

3. What are arteries and veins?

Organs, muscles, and other tissues receive oxygen-rich blood carried by arteries from the heart. This process is called reoxygenation and is done by the return of exhausted blood to your heart via veins.

4. What are the functions of the circulatory system?

The main function of our circulatory system is to deliver oxygen-rich blood to all parts of our bodies so that we can live and function normally. Another important function is that it removes waste products from our bodies, such as carbon dioxide (CO2).


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