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What are Blood Vessels?

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Blood Vessels

Blood vessels form a tubular network throughout the body that permits blood to be due to the guts to all or any of the living cells of the body then back to the guts. Blood from the guts passes through blood vessels of progressively smaller diameters that are referred to as arteries, arterioles and capillaries. These are the three types of blood vessels. 

Layers of Blood Vessels

The walls of arteries and veins contain three coats. They are known as layers of blood vessels. These coats also are referred to as tunics.

  • Tunica Externa: The outermost layer is the tunica externa and consists of connective tissue.

  • Tunica media: The centre layer is the tunica media and consists primarily of smooth muscles.

  • Tunica interna: The inner layer is that of the tunica interna. It consists of two parts that are elastic membrane and endothelium. The elastic membrane is formed from the connective tissue of yellow fibres which are bundles of elastin protein. it's thicker in arteries. The endothelium is formed from flattened squamous epithelial cells lining the lumen. Its cells are more elongated in arteries. We will learn more about the types of blood vessels and the functions of blood vessels. 


  • Arteries distribute blood from the guts to the various parts of the body.

  • Tunica media is thick, having more muscle fibres.

  • Tunica interna features a strong elastic membrane and more elongated endothelial cells.

  • Arteries aren't collapsible as they need thick walls.

  • Arteries haven't any walls.

  • The flow of the blood is fast because the blood in them is under great pressure.

  • Except for the pulmonary arteries, all the arteries carry oxygenated blood.


  • Veins collect blood from different parts of the body and pour it into the guts.

  • Tunica media is thin, having fewer muscle fibres.

  • Tunica interna features a simple, elastic membrane and elongated cells.

  • Veins are collapsible because they need thin walls.

  • Veins have valves that prevent the backward flow of blood.

  • The flow of blood in veins isn't so fast because the blood within the veins is low.

  • Except for pulmonary veins, all the veins carry deoxygenated blood


These are the narrowest blood vessels, through which the exchange of gases and nutrients between the blood and therefore the tissue fluid occurs. The walls of capillaries are composed of only one cell layer whose layer is straightforward epithelium or endothelium. This allows a more rapid exchange of materials between the blood and therefore the tissues. From the above paragraphs, we got a clear understanding of what are blood vessels. 

Disease Caused By Blood Vessels

Due to the buildup of minerals within the arteries and veins, there are various diseases that will happen which is said to affect the cardiovascular system.

High Vital Sign: Hypertension is that term for blood pressure that's above normal. During this measurement, 120mm Hg is the systolic, or pumping, pressure and 80mm Hg is the diastolic, or resting, pressure. If repeated checks of the vital sign of a private are 140/90 or higher, it shows hypertension which results in heart diseases and also affects vital organs just like the kidney and brain.

Angina Pectoris: A symbol of acute pain that appears when not enough oxygen is reaching the guts muscle. The term angina means pain. It can occur both in men and ladies of any age but is more common among middle-aged and elderly people. It occurs thanks to conditions that affect blood flow.

Heart Failure: It's a state of the guts when it doesn't pump blood effectively enough to satisfy the requirements of the body. It's sometimes called a congestive coronary failure because congestion of the lungs is one of the most symptoms of this disease.

Heart Attack: Attack occurs when the guts muscles are suddenly damaged by an inadequate blood supply.

Cardiac Arrest: Asystole means complete stoppage of the guts beat that's when the heart stops beating.

Coronary Artery Disease: Arteria coronaria disease often mentioned as atherosclerosis, affects the vessels that provide blood to the guts muscle. It's caused thanks to the deposition of calcium, fat, cholesterol, and fibrous tissues within the arteries supplying the guts musculature. These depositions make the lumen of arteries narrower.

Varicose Veins

The accumulation of blood within the veins of the legs over an extended period of your time, as may occur in people with an occupation that needs standing still all day, can cause the veins to stretch to the purpose where the venous valves are not any longer efficient. The leg muscles don't contract to compress the veins for upward movement of blood. This causes the pooling of blood within the leg veins because the blood is unable to ascend against gravity. the guts don’t receive enough blood to take care of the specified supply of blood to the brain, therefore less oxygen and nutrients are received by the person. The person may therefore faint and fall.

Functions of the Blood Vessels

  • Arteries carry oxygenated blood faraway from the body apart from the arteria pulmonalis.

  • Veins carry deoxygenated blood towards the body apart from the vena pulmonalis.

  • Capillaries help to exchange wastes, nutrients, gases and minerals.

  • All these three help in maintaining the constant pumping of the guts.

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FAQs on What are Blood Vessels?

1. Name Three Types of Blood Vessels.

Answer: The three types of blood vessels are Arteries, capillaries and veins.

2. What are Blood Vessels?

Answer: As their name suggests that these blood vessels carry blood to different organs of the body. Arteries, veins and capillaries are the three types of blood vessels.