Circulatory system vs Cardiovascular system

Technically, the cardiovascular system (heart and blood vessels) is comprised of the heart and blood vessels and is a component of the circulatory system. The two terms circulatory system and cardiovascular system are often used interchangeably. The circulatory system includes not only the cardiovascular system but also the lymphatic system and blood that maintain the body’s internal environment.

‍

The cardiovascular system pumps blood, while the circulatory system transports blood and all its constituents.

‍

In this blog, we will explore what circulatory and cardiovascular systems are, how they differ, and how they work together to sustain life.

‍

What is the circulatory system?

The circulatory system includes the heart, blood vessels, and blood circulating in the body, while the cardiovascular system consists of the heart and blood vessels. The circulatory system has two divisions.

• Pulmonary circulation: It is from the right side of the heart, taking deoxygenated blood to the lungs, where it is oxygenated and returned to the left side of the heart.
• Systemic circulation: It delivers oxygenated blood from the left heart to the rest of the body and returns deoxygenated blood to the right side through the large veins.

‍

Components of the circulatory system

• Heart
  
  • The heart pumps blood to all parts of the body. It is comprised of two upper and two lower chambers (atria and ventricles).

‍

• Blood vessels

Arteries, veins, and capillaries are the blood vessels of the circulatory system.

• The arteries supply oxygenated blood (pulmonary artery being the exception) to other parts of the body from the heart. The aorta is the first part of the systemic circulation and is the thickest part. It gradually branches into smaller arteries.
• The arteries branch into arterioles and then into capillaries. The capillaries then unite to bring blood into the venous system.
• Capillaries merge into venules, which form the veins. The Venous system is comprised of two major veins, the
  
  • superior vena cava, which drains the tissues above the heart.
  • inferior vena cava, which drains tissues below the heart.

• Blood
  
  • A fluid that contains red and white blood cells, platelets, and plasma, responsible for transporting essential supplies

‍

Circulatory system and its functions

The heart circulates about 7500 liters of blood every day. If the blood supply to the brain is hampered within 4 minutes, the cells get damaged. Similarly, heart cells are damaged if the blood supply to them is restricted. The circulatory system has three basic functions.

• Move blood throughout the body.
• Provide oxygen and nutrients to all parts of the body.
• Remove waste products like carbon dioxide and other chemical byproducts.

‍

What is the cardiovascular system?

The cardiovascular system is responsible for delivering blood to different parts of the body. It consists of

• Heart
• Closed system of blood vessels.
  
  • Arteries that carry blood away from the heart.
  • Veins that bring blood back to the heart.
  • Capillaries, the tiny blood vessels.

‍

Differences between cardiovascular and circulatory systems

‍

‍

The role of the lymphatic system

The lesser-known part of the circulatory network is the lymphatic system. It is vital for keeping our body healthy. It complements our cardiovascular system, collects fluid that leaks out of the blood vessels into the body tissues, and returns it to the bloodstream.

‍

Functions of the lymphatic system

• Maintain fluid balance: It prevents the buildup of fluid and tissues by continuously draining and recycling the fluid back into the blood circulation.
• Absorb fat: Lymphatic vessels in this intestine absorb dietary fats and fat-soluble vitamins and help them enter blood capillaries.
• Defence: Lymph nodes filter harmful substances and fight infections.

‍

Blood circulation is a closed circulation, while the lymphatic circulation is an open system where the lymph flows slowly in one direction. The lymph flow depends on muscle movements, breathing, and valves.

‍

How do the two systems work together?

The two systems help to maintain the body’s internal balance whenever plasma seeps out of the capillaries into the surrounding tissues to deliver nutrients and oxygen. The lymphatic system collects this and returns it to the bloodstream.

‍

The exchange of fluids between blood and lymph ensures the tissues are properly nourished and there is no fluid overload. Together, they create a stable internal environment essential for all normal body functions.

‍

The circulatory system keeps the blood circulating and delivers essential supplies. The lymphatic system balances the fluid level, transports fat, and provides immune defense. The collaboration between the two systems ensures nourishment, protection, and equilibrium to all cells of the body. 

‍

Disorders of the circulatory and cardiovascular system

The earlier cardiovascular disease is detected, the sooner it can be managed with fewer complications. The disorders usually manifest as

• Lightheadedness
• Dizziness
• Blurred vision
• Fainting
• Shortness of breath
• Chest pain

‍

The common conditions and disorders that affect our circulatory and cardiovascular systems

• High blood pressure
• High cholesterol
• Arrhythmia
• Heart attack
• Stroke
• Atherosclerosis
• Vascular diseases like deep vein thrombosis or pulmonary embolism

‍

Conclusion

The cardiovascular system and circulatory system are closely related, but they are not the same. The cardiovascular system includes the heart and blood vessels, while the circulatory system includes both the cardiovascular and lymphatic systems. They help to keep the body's fluids moving, deliver oxygen and nutrients, remove waste, and protect against infections.