Difference Between Arteries and Veins

Arteries and Veins

Two main types of blood vessels functioning in the circulatory system of our bodies are arteries and veins. Both arteries and veins cooperate for transporting blood throughout the body, aiding to oxygenate, and to deoxygenate every cell with every heartbeat. Arteries carry oxygenated blood from the heart to various body parts and body tissues whereas veins carry deoxygenated blood from various parts of the body and tissues to the heart to re-oxygenate. Their functions are associated with removing wastes from each body cell.

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What are Arteries?

Blood vessels that carry blood away from the heart to other parts of the body are called arteries. These are tube-like shaped and form branches called arterioles that reach tissues and organs. While heart contraction occurs, arteries pump blood to all the body parts. Aorta is the largest artery in the human body that is attached to the left ventricle of the heart. An artery that differs from the rest and is located attaching to the right ventricles is Pulmonary Artery as it carries low oxygen blood to the lungs where it further branches into capillaries and arterioles. It helps the blood to take up oxygen before returning to the heart via a pulmonary vein. 

The Three Types of Arteries and Arteries Functions are:

  1. Elastic Arteries: Also known as conducting arteries, these comprise a thick middle layer stretching in response to each heart pulse. It has the ability to stretch as it has numerous collagen and elastin filaments.

  2. Muscular Arteries: Also known as distributing artery, these medium-sized arteries draw blood from an elastic artery to branch into smaller arteries and arterioles known as resistance vessels. These comprise numerous smooth muscles that allow easy expanding and contracting depending on blood demand.

  3. Arterioles: Small-diameter blood vessels that extend from an artery and lead towards capillaries are called arterioles. Oxygen and nutrients pass into tissues from the blood through the thin capillary walls.

What are Veins?

Blood vessels that carry deoxygenated blood from body parts or tissues back to the heart are called veins. Like arteries, these are an important part of our circulatory system but have thinner walls than arteries. Thinnest veins are called venules that receive blood from the capillaries and deliver it to the larger veins. The largest vein in the human body is the superior and inferior vena cava that directly drain into the right atrium of the heart.

There are Three Different Types of Veins, Namely-

  1. Deep Veins: It is located deep within the body. It is different from superficial veins that are located close to the body’s surface. If a blood clot in the deep veins inside our body, the condition is called Deep Vein Thrombosis (DVT). It normally occurs in the lower leg, pelvis or thigh area.

  2. Superficial Veins: The veins that are easily visible in places like arms and cow’s udder are superficial veins as these are located closer to the surface of the skin. Superficial venous disease is the risk factor associated with these veins.

  3. Pulmonary Veins: Veins that are located throughout the body to carry or transport deoxygenated blood to the heart for reoxygenation are called pulmonary veins. The largest pulmonary veins include the four main pulmonary veins, two originate from each lung that drains into the left heart atrium.

Arteries and Veins Difference

Sl.No.

Characteristic

Arteries

Veins

1.

Blood Type

Arteries carry pure and oxygenated blood which is rich in nutrients, except the pulmonary artery.

Veins carry impure, deoxygenated blood except for the pulmonary vein.

2.

Walls

Arteries have rigid, highly muscular, and thicker walls.

Veins have thin and collapsible walls.

3.

Body Location

Arteries are located deep within the body.

Veins are superficial and peripherally located closer to the skin.

4.

Colour

Arteries are red-colored vessels.

Veins are blue colored vessels.

5.

Blood flow direction

These carry blood from the heart to various body parts and tissues.

Veins carry blood from the various parts of the body and tissues to the heart.

6.

Pressure

Blood flows through arteries under high pressure.

Blood flows through veins under low pressure.

7.

Valves

No valves are present.

Valves are present here to prevent the backward blood flow.

8.

Level of Oxygen

Arterial blood has higher oxygen levels.

Veins have a lower oxygen level.

9.

Carbon Dioxide Level

Arterial blood has low CO2.

Venous blood has a high level of CO2.

10.

Lumen

It has narrowed lumen.

It has a wide lumen.

11.

Valves

Absence of valves in these vessels.

Valves are present in the veins that allow blood flowing in the upward direction.

12.

Diseases

Certain artery related diseases such as atherosclerosis, renal vascular disease, and pectoris exist.

Very few veins related diseases are known such as varicose veins.


FAQ (Frequently Asked Questions)

1. What are the Different Layers of the Vein and Artery? 

There are three different layers of arteries and veins, namely-

  • Tunica intima (the innermost layer)

  • Tunica media (the middle layer)

  • Tunica adventitia (the outermost layer)

2. Which is the Largest Artery in the Human Body and What is Its Role?

The largest artery in the human body is Aorta where the left ventricle pumps blood to distribute blood to the whole body. It breaks into arteries and then to fine structures called arterioles. Its huge importance lies in the fact that it directly connects to the heart and is the initial point for blood transportation to the entire body system.

3. Name the Largest Vein in the Human Body?

The largest vein in the human body is the inferior vena cava, which carries low oxygen (deoxygenated) blood from the lower half portion of the body back up to the heart.

4. Mention the Major Arteries and Vein Differences.

Arteries are the blood vessels that carry blood with high oxygen amounts from the heart to all other parts, tissue, and organs of the body. On the other hand, veins are the blood vessels that carry blood with low oxygen amounts from various body parts, organs, and tissues to the heart. The exceptions for both the categories are pulmonary arteries and pulmonary veins that function opposite to the normal arteries and veins.