Arteries in the Body: What Are Their Functions?

Arteries are blood vessels in the body that carry blood away from the heart and throughout the body. There are two types of arteries: systemic arteries and pulmonary arteries. Systemic arteries carry oxygen-rich blood from the left side of the heart to the body by way of the body's largest artery, the aorta. Pulmonary arteries carry oxygen-depleted blood from the right side of the heart to the lungs.

Arteries can be thought of as a system of pipes that branch into narrower blood vessels, called arterioles, until reaching capillaries, where oxygen exchange occurs. Arteries also have muscles that allow them to constrict and widen to regulate blood passage and blood pressure. Several serious conditions affect the arteries, including aneurysms, atherosclerosis, and dissection.

This article will discuss arteries, including their structure, function, and ways to keep these important structures healthy.

Arteries, Blood, and the Heart

The cells and tissues that make up the body require oxygen and nutrients from the blood. You can think of the heart as a muscular pump and the blood vessels as pipes. Arteries are pipes that carry blood away from the heart, whereas veins carry blood toward the heart.

The flow of blood in the body is as follows: After getting oxygen from the lungs, blood travels back to the left side of the heart, where it is pumped out into the body's largest artery, the aorta. The aorta branches into several large and medium-sized arteries that further branch into smaller arterioles.

Eventually, blood enters capillaries, where oxygen passes from the arteries directly into tissues. The now oxygen-depleted blood travels through veins to the right side of the heart. From here, it's pumped through the pulmonary arteries to the lungs to pick up more oxygen. The pulmonary veins lead the now oxygen-rich blood back to the left side of the heart, where the process continues.

How Arteries Differ From Veins

Arteries and veins are both types of blood vessels. However, they have several important differences. Firstly, arteries carry blood away from the heart to the body. For the most part, arteries carry oxygen-rich blood, with the notable exception of the pulmonary artery, which carries oxygen-depleted blood from the right side of the heart to the lungs to get oxygen.

Veins, on the other hand, carry blood toward the heart. For the most part, they carry oxygen-depleted blood from the tissues in the body. The notable exception is the pulmonary veins that carry oxygen-rich blood from the lungs to the left side of the heart, which is pumped into arteries to go to the body.

Additionally, the structure of arteries and veins has some important differences. Arteries are thicker-walled, muscular tubes that accommodate higher pressures. Veins, on the other hand, are thinner structures that can easily dilate. Also, unlike arteries, veins have valves to prevent backflow of blood.

Location of Major Arteries

There are several major arteries in the body. The largest artery is the aorta, which carries blood from the heart and travels down through the chest and abdomen, giving off branches that lead up to the head, arms, abdominal and pelvic organs, and legs.

The body's major arteries are:

• Coronary arteries: Supply blood to the heart
• Pulmonary arteries: Lead from the right side of the heart to the lungs
• Carotid arteries: Arteries in the neck that branch into various arteries that supply the head, including the brain (cerebral arteries), eyes (ophthalmic arteries), and face (facial arteries)
• Subclavian arteries: Lead to the armpits, supplying blood to the arms
• Celiac trunk: Branches into the left gastric artery, the common hepatic artery, and the splenic artery
• Superior and inferior mesenteric arteries: Supply blood to the colon
• Renal arteries: Supply blood to the kidneys
• Iliac arteries: Branch into the femoral arteries, popliteal arteries, and posterior tibial and dorsalis pedis arteries that supply the lower extremities

Anatomy of Arteries

Arteries are muscular tubes that can constrict and dilate to regulate blood flow and blood pressure in the body.

External Appearance

From the outside, arteries look like pulsating tubes. They are often depicted as red in medical illustrations (as opposed to veins, which are portrayed as blue). However, they are a shiny white, with noticeable small blood vessels surrounding them. This is the vasa vasorum, which supplies blood to the arteries themselves.

Artery Structure

Arteries have three layers, as follows:

• Tunica intima: The innermost layer, it is made up of epithelial cells.
• Tunica media: The middle layer and thickest part, it is made of muscle responsible for dilation (widening) and constriction (narrowing) to regulate blood flow and pressure.
• Tunica adventitia (or tunica externa): The outermost layer of the artery wall, it is responsible for the shape and strength of the arteries.

Healthy vs Clogged Arteries

There are several conditions that can affect the arteries, leading to vascular disease. One of the most common conditions is atherosclerosis, which is the buildup of cholesterol plaque (a sticky substance made up of cholesterol, fat, and other components) on the inner walls of arteries.

Atherosclerosis may impair blood flow or "clog" arteries. It can lead to the formation of blood clots, which may abruptly block blood flow leading to death of the tissue or organ. Depending on the location, it can cause potentially fatal complications such as heart attack and stroke.

How to Improve Artery Health

The following lifestyle habits are recommended to keep your arteries as healthy as possible, and to prevent cardiovascular disease:

• Get regular physical exercise, aiming for at least 150 minutes of moderate-intensity physical activity or 75 minutes of vigorous physical activity per week.
• Eat a heart-healthy diet rich in fruits, vegetables. For protein, eat beans, legumes, fatty fish and lean meats. Avoiding ultra-processed foods which are often high in sodium and trans fats.
• Quit smoking, and avoid secondhand smoke.
• Aim for seven to nine hours of quality sleep each night.
• See your healthcare provider to screen for and treat underlying conditions like high blood pressure, high cholesterol, and diabetes.

You can discuss with your healthcare provider whether screening for aortic conditions is right for you. For example, the following people are at higher risk of aortic aneurysm and some guidelines recommend screening with medical imaging such as ultrasound:

• History of smoking, especially for those age 65–75 years
• Family history of aortic aneurysm in a 1st degree relative (such as parent or sibling)
• Known connective tissue disorder, such as Marfan syndrome or Ehlers-Danlos

Summary

Arteries are tubular structures that carry blood away from the heart to the rest of the body. Systemic arteries carry oxygen-rich blood from the heart to the body, whereas pulmonary arteries carry oxygen-depleted blood to the lungs to get more oxygen.

Several conditions can affect arteries, including aneurysm and atherosclerosis. To keep your arteries healthy, practice healthy lifestyle habits like getting regular exercise, eating a heart-healthy diet, quitting smoking, and treating risk factors like high blood pressure, cholesterol, and blood sugar.