How many blood vessels are in a person s body? How long are the blood vessels in the human body

The blood vessels in the human body are like rivers crisscrossing the earth, distributed in every corner of our body, and together with the heart, they form a continuous closed delivery pipe in the human body, so that the pipes extend in all directions in the body and can transport blood to the whole body.

There are three types of blood vessels: arteries, veins and capillaries.

On the surface of the body, beating blood vessels can be felt, which are arteries. It is used to transport nutrients in the blood, such as oxygen, sugar, vitamins, amino acids, inorganic salts, etc., to various tissues of the body, so that various tissue cells can grow and multiply, and maintain human life activities.

The blood vessels that are blue and purple on the surface of the human body and on the limbs and cannot beat are the veins. Its function is just the opposite, which is to take away the waste products metabolized by the cells of various tissues, such as carbon dioxide and urea, send carbon dioxide to the lungs and excrete it from the body, and send urea to the kidneys to excrete it from the body.

And capillaries, much thinner than human hair, are invisible to the naked eye, with a diameter of only 5 20 microns. Capillaries can only pass through a single single cell. Capillaries act like irrigation channels, carrying blood to all parts of the body.

Blood is pumped out and pumped in the heart and circulates repeatedly in the blood vessels, repeating itself and never stopping. If you include capillaries, the length of blood vessels in the human body is at least 10,000 kilometers, which is scary enough!

10,000 kilometers, the earth's equator is 40,000 kilometers long, and it can circle more than twice.

The whole body of the human body is full of blood vessels (arteries. Vein. Capillary. There are many, many kinds) blood vessels are divided into static and arterial ones.

Everything else is just a small branch.

There are about 250 trillion blood vessels in the human body.

They are all connected, so in general they can only be counted as one.

Each square human body** contains 19 feet of blood vessels, with a total length of more than 62,000 miles (1 mile = kilometer), and if they were all connected end to end, they would probably circle the earth.

Arteries originate from the heart, continue to branch, the caliber becomes tapered, the wall gradually thins, and finally divides into a large number of capillaries, which are distributed to various tissues and cells throughout the body. The capillaries rejoin, progressively forming veins and finally returning to the heart. Arteries and veins are the pipes that carry blood, capillaries are the places where blood and tissues exchange substances, arteries and veins are connected through the heart, and blood vessels throughout the body form closed pipes.

There are 96,000 kilometers of blood vessels in the human body, the length of this blood vessel includes the length of arteries, veins and capillaries, of which capillaries account for the main length of blood vessels in the human body, although the capillaries in the search and combustion hall are short, but because of the large number, thousands of capillaries constitute the capillary network in the human body, so the total length has reached 96,000 kilometers.

The circumference of the earth is 40,000 kilometers, that is, the total length of blood vessels in the human body can circle the earth for two and a half weeks, and it is precisely because there are so many capillary networks that if there is a rupture of arterioles or segmental veins in the human body, it will not affect the local blood circulation.

Blood vessels are the largest system in the human body. The vascular system is composed of veins, arteries and capillaries, with a total length of about 10,000 kilometers (if connected, it can circle the earth twice) and a surface area of more than ——— hectares.

The main part of the length of the vascular system is the "capillary network". "Although the length of each capillary is very short, there are thousands of capillaries in the human body, so the total length is very considerable. ”

The total length of blood vessels in the human body is about 96,000 kilometers, while the length of the earth is about 40,000 kilometers, so blood vessels can circle the earth for two and a half weeks.

The blood vessels of the human body are dense, all over the body, organs and tissues, and the blood vessels of the human body are divided into arteries, veins and capillaries. The human heart pumps blood each time, through the large arteries, middle arteries, arterioles, and finally through the capillaries into the venules, middle veins, then into the large veins, and finally back to the heart. There are more than 100 billion blood vessels in the human body, so every time the heart pumps blood, it will pass through the capillaries intact, and finally flow back to the heart through the veins, which plays a role in the transfer of nutrients and nutrients.

Therefore, any blood vessel with a thrombosis or occlusion will produce corresponding symptoms.

If all the arteries, veins and capillaries in an adult's body were connected, it would be about 150,000 kilometers long, which would be about two and a half weeks around the earth.

Classification of human blood vessels.

1. Arterial blood vessels: Arteries are blood vessels that transport blood out of the heart, and after emitting from the ventricles, they branch repeatedly, becoming thinner and thinner, and finally migrate to the capillaries. Arterial walls are thicker and can withstand greater pressure.

The wall of the aortic artery has more elastic fibers and greater elasticity, and the wall of the canal expands during ventricular ejection and retracts during ventricular diastole, so that the blood continues to flow forward. The smooth muscles of the arteriole and small arterioles, especially the small arteriole walls, are well developed and can contract or relax under the regulation of nerve humoral to change the lumen and size, affecting the local blood flow resistance.

2. Venous blood vessels: blood that flows back to the heart through capillaries, or blood that bursts from the heart to the lungs is called venous blood. The walls of the veins are thin, the elasticity is poor, there are venous valves, the blood flow rate is slow, and varicose (especially in the lower limbs) is prone to occur, because the blood has exchanged nutrients in the capillaries and the tissues of the body, so the venous blood is dark red.

3. Capillaries: Capillaries, also known as microvessels, refer to the microvessels of the cardiovascular system, which can only be seen under the microscope. Microvasculature refers to the small blood vessels connecting arterioles and venules, distributed in various tissues and organs, and the branches are connected into a network, so it is also called the terminal vascular bed.

In the order of vascular branches, microvessels mainly include arterioles, capillaries, and venules; Some also have two types of short circuits that directly connect arterioles and venules: direct access and arteriovenous anastomosis.

Human vascular action.

Blood vessels are the channels through which blood is transported by organisms, and can be divided into arteries, veins and capillaries according to the direction of transportation. Arteries carry blood from the heart to body tissues, veins bring blood from interstitial tissues back to the heart, and microvessels connect arteries and veins, where blood and tissues are exchanged for substances. Various organisms possess different types of blood vessels.

Open circulation organisms, such as insects, have only arteries. Blood flows out of the arteries and directly into contact with the tissues of the body, and then through the openings in the heart** blood. Closed-loop organisms, such as mammals, birds, reptiles, and fish, are connected by arteries to capillaries, to veins, and finally to the heart.

My neighbor has coronary heart disease. Now that it's cold, he's very well protected. I wear a warm dress every day, and I basically don't go out when it's cold.

He was introduced by a patient to take Yi'an Ning Pills. Now the whole person is recovering very well. He now eats a lighter diet and still insists on exercising every day.

It is possible to circle the earth for two and a half weeks.