What Is an Artery? Structure, Functions and Types of Arteries

Arteries are thick-walled blood vessels that originate from the heart and carry oxygen-rich blood to tissues. As one of the main components of the circulatory system, arteries ensure that cells receive the oxygen and nutrients they need by transporting blood from the heart to organs thanks to their elastic structures that can withstand high pressure.

The main function of arteries is to deliver the blood pumped by the heart to all tissues of the body through systemic circulation. These vessels generally carry oxygen-rich blood and branch into smaller vessels as they move away from the heart, turning into arterioles and capillaries, thus enabling substance exchange at the cellular level.

In systemic circulation, arterial blood carries oxygen-enriched blood from the left ventricle of the heart to all body tissues, including the brain, muscles, and internal organs. This process ensures the regular distribution of oxygen and nutrients necessary for maintaining cellular metabolic activities.

The arterial wall structure and pressure characteristics are defined by a strong and elastic vessel structure composed of three layers. The thick muscle layer and elastic fibers balance the high-pressure blood flow coming from the heart and help maintain the stability of the circulatory system by ensuring that blood moves continuously and regularly.

Things You Should Know	Information
What is an artery	Arteries are vessels that originate from the heart and carry oxygen-rich blood to body tissues. As an exception, the pulmonary artery carries oxygen-poor blood to the lungs.
Functions	They ensure the delivery of oxygenated blood and nutrients to organs and tissues. They also contribute to the regulation of blood pressure.
Structural features	They have thick and elastic walls. They consist of three layers: tunica intima (inner), tunica media (middle, contains smooth muscle), tunica adventitia (outer). This structure is resistant to high-pressure blood flow.
Direction of blood flow	Carries blood from the heart to organs and tissues.
Type of blood carried	Generally carries oxygenated (oxygen-rich) blood. The pulmonary artery is an exception and carries oxygen-poor blood.
Examples of arteries	Aorta, carotid artery (neck), femoral artery (leg), brachial artery (arm), pulmonary artery (lungs).
Pulse detection	Arteries are vessels where the pulse can be felt because they expand with each heartbeat.
Blood pressure	Blood pressure is high in arteries. Therefore, their walls are thicker and more elastic than veins.
Clinical importance	Blockages in arteries (e.g., atherosclerosis) can obstruct blood flow to vital organs and lead to serious conditions such as heart attack and stroke.

What Is an Artery and What Are Its Fundamental Characteristics in Our Body?

Blood circulation in our body is a closed system that operates in great harmony. Within this system, the most prominent characteristic of arteries is that they function under high pressure. Each time the heart contracts, it forcefully ejects the blood inside it. The arteries are the first place where this ejected blood is received and distributed throughout the body. This high-pressure pulse creates a noticeable wave in the vessel walls; the pulse we feel from our wrist or neck is actually nothing more than this stretching movement created in the arterial wall by the blood pumped by the heart.

The system is built on a very delicate balance. The highest pressure in the vessel during the contraction of the heart is called systolic pressure, while the lowest pressure remaining in the vessel when the heart muscle relaxes and fills with blood for the next beat is called diastolic pressure. These values are commonly known as high blood pressure and low blood pressure. The elastic structure of arteries softens the difference between these two pressures, allowing blood flow to our organs to continue uninterrupted, smoothly, and continuously.

What Layers Make Up an Artery and What Are Their Characteristics?

A structure that is constantly exposed to high pressure must be extremely durable. When examined at the microscopic level, the wall of an artery consists of three different protective layers nested within each other. Each of these layers has critically important functions. On the innermost side, there is a smooth surface in direct contact with blood, similar to a non-stick pan. This smoothness allows blood to flow without obstruction and prevents clotting. In the middle, there is a thick muscle layer that gives the vessel its strength, and on the outermost side, there is a protective sheath that connects the vessel to surrounding tissues.

The layers forming the vessel wall are:

• Intima
• Media
• Adventitia

The health of these layers is a direct reflection of overall vascular health. In particular, the disruption of the smooth structure of the innermost layer for various reasons is the stage where the first seeds of major problems such as atherosclerosis are sown.

Where Does Arterial Blood Carry and Does It Always Carry Clean Blood?

The general route of arteries is always outward from the heart toward the tissues. The aorta, the main artery leaving the left ventricle, first curves upward and gives off branches to the brain and arms. Then it descends through the chest and abdominal cavity, providing rich blood flow to all internal organs such as the liver, stomach, intestines, and kidneys. Finally, it divides into two in the groin region and extends down to the legs and the tips of the feet.

There is a common belief in society that arteries always carry oxygen-rich, or “clean,” blood. However, there are always exceptions in medicine. While the systemic circulation carries clean blood to nourish the body’s cells, there is another mechanism called pulmonary circulation. The pulmonary arteries, which exit from the right side of the heart and go directly to the lungs, carry “dirty” blood that has circulated through the body, lost its oxygen, and become loaded with carbon dioxide. After being cleaned in the lungs, this blood returns to the heart.

What Are the Types of Arteries in Our Body?

The amount of blood required by each region of our body and the level of pressure to which vessels are exposed differ greatly. Coping with the storm created by blood freshly pumped from the heart requires a different level of durability, while nourishing the delicate tissues inside our eyes requires a much more sensitive structure. For this reason, arteries show structural differences depending on their location and diameter.

The main types according to vessel structure are:

• Elastic
• Muscular
• Arteriole

The large vessels closest to the heart contain abundant elastic fibers, allowing them to absorb massive pressure by stretching like a spring. As these vessels progress toward the organs, they become smaller and the amount of muscle in their walls increases. This muscular structure regulates blood flow by increasing or decreasing it depending on the needs of each organ. At the farthest points, the vessels become so small that they are no longer visible to the naked eye.

What Is the Connection Between Arteries and Capillaries?

The journey of arteries carrying blood ends in the depths of the tissues. When they reach the endpoints, arteries give way to capillaries. Capillaries are so incredibly thin that red blood cells can pass through them only by bending and twisting, almost in single file.

This extraordinary close contact is where the secret of life takes place. As the blood cell slowly passes through the capillary, it releases oxygen and nutrients into the cells by diffusing through the vessel wall. At the same time, it absorbs waste products and carbon dioxide produced by the cells. The ultimate purpose of the entire massive high-pressure highway system is to ensure that this silent exchange at the microscopic level occurs perfectly.

What Are Common Arterial Diseases?

As human lifespan increases and sedentary lifestyles become more widespread with modern living, we encounter arterial diseases much more frequently. Under normal conditions, these vessels, which are smooth like glass and highly elastic, begin to wear out slowly over the years. Cholesterol, calcium, and some other waste substances in the blood begin to seep from the smooth inner surface of the vessel and accumulate within the wall. These deposits harden over time and form structures called plaques.

The main conditions leading to atherosclerosis are:

• Atherosclerosis
• Calcification
• Plaque accumulation

As these plaques grow, they narrow the inner lumen of the vessel and significantly reduce the amount of blood passing through it. When tissues cannot receive the blood they need, they begin to experience starvation at the cellular level. This situation creates the basis for serious problems, especially in the heart, brain, and leg vessels. The disease can progress silently for years without showing any symptoms.

What Symptoms Occur in the Body in Arterial Blockage?

When the vessel begins to narrow, the body tries various ways to compensate, but after a certain point, the lack of oxygen in the tissues signals itself with warning signs. Blockages in the arteries that supply the legs, in particular, deeply affect patients’ daily lives. Complaints that initially occur only during exertion begin to disturb the person even at rest as the disease progresses.

The most typical symptoms are:

• Pain
• Cramp
• Numbness
• Tingling
• Coldness
• Paleness
• Wound

The most characteristic finding is severe cramp-like pain in the calves after walking a certain distance, forcing the person to stop and rest. When the patient rests for a few minutes, the pain subsides as the muscles’ oxygen demand decreases, but it reappears at the same distance when walking resumes. If the blockage is very advanced, the tissues may become so deprived of nutrients that non-healing wounds or tissue death can begin at the tips of the toes.

What Is Arterial Aneurysm (Ballooning) and Why Is It Dangerous?

Unlike blockages, in some arterial diseases, the vessel does not narrow; instead, the vessel wall expands excessively. When the vessel wall loses its structure and weakens due to genetic factors, high blood pressure, or aging, it bulges outward like a balloon, a condition known as an aneurysm. This condition is most commonly seen in the aorta, the largest artery in our body.

Aneurysms usually do not cause any discomfort to the patient and are often detected incidentally during ultrasound or tomography scans performed for other reasons. However, this silence is extremely deceptive. As the balloon expands, the wall becomes thinner, and the high blood pressure generated by each heartbeat continuously strikes this thin wall from the inside. If the aneurysm exceeds a certain diameter, the weakened vessel wall may suddenly rupture. This can cause severe internal bleeding that may lead to death within minutes.

Why Is Sudden Arterial Blockage an Emergency?

Unlike atherosclerosis that develops slowly over years, arteries can sometimes become suddenly blocked within seconds. This usually occurs when a blood clot formed in the heart of patients with heart rhythm disorders breaks off and is carried by the bloodstream to suddenly block an artery in areas such as the leg, arm, or brain. This is called an embolism.

Organs can adapt somewhat to a gradual decrease in blood flow, but they have no defense against a sudden, complete interruption. A sudden, extremely severe and unbearable pain occurs in the affected area. The limb becomes ice-cold, pale, and the person loses sensation and movement in that area. This condition is a true emergency where even seconds are critical. If the clot is not removed in a very short time, there is a risk of permanent loss of the limb.

What Is Interventional Radiology in the Treatment of Arteries?

In the past, the only option to open a blockage in arteries or repair a bleeding area was major and challenging open surgery. Large incisions were made in the patient’s body, and procedures were performed by directly accessing the vessel. However, thanks to tremendous advances in medical technology, a new era has opened in the treatment of these diseases. This era is called interventional radiology.

Interventional radiology is the art of reaching vessels deep within the body without making large external incisions, guided by very clear and real-time images provided by ultrasound, angiography, or tomography devices. Using very thin, high-tech needles, wires, and tubes (catheters), the vascular system is accessed through a tiny puncture in the skin. This allows the physician to navigate inside the vessels like traveling on a highway and directly treat the diseased area from within.

What Are the Advantages of Interventional Methods Compared to Arterial Surgery?

The advantages of this modern treatment approach compared to traditional open surgery are so numerous that it has become the first preferred method in many vascular diseases today. These methods are especially life-saving for elderly patients, those with heart conditions, or those at risk of undergoing general anesthesia.

The main advantages are:

• Incision-free
• Suture-free
• No general anesthesia
• Scarless
• Painless
• Safe
• Fast

Since there is no large surgical wound, post-procedure pain is minimal. Sedation instead of general anesthesia eliminates the risk of being connected to a ventilator. While traditional vascular surgery requires hospitalization for days, patients undergoing these minimally invasive procedures can usually return home and resume normal life the next day. The very low risk of bleeding and infection also significantly increases comfort during recovery.

How Is a Blocked Artery Opened with Balloon and Stent Methods?

The most commonly used method for treating calcified plaques that narrow arteries is to widen the vessel from the inside using a minimally invasive approach. The procedure usually begins with local anesthesia applied to the artery in the groin area. A thin guidewire is inserted and advanced in the direction of blood flow to safely reach the narrowed or blocked area.

A special medical balloon in a deflated state is positioned at the site of the blockage over this wire. When the balloon is inflated with controlled high pressure from outside, it forcefully compresses the hard plaques against the vessel wall, creating a wide tunnel through which blood can flow freely. However, in some cases, ballooning alone is not sufficient; to prevent the crushed plaques from collapsing back into the vessel over time, a supporting structure is needed. For this purpose, stents—flexible metallic mesh structures—are permanently placed inside the vessel. The stent supports the artery from within like a scaffold, keeping it open for life.

How Is Arterial Aneurysm Treated with a Minimally Invasive Method?

The treatment of aneurysms, especially in the aorta, is one of the most impressive technological advancements in medical history. These high-risk surgeries, which previously required opening the chest or abdominal cavity, can now be performed entirely with minimally invasive methods using advanced stent grafts.

Through a small puncture in the groin vessels, a special catheter system is advanced into the aorta. At the tip of the catheter is a stent system covered with a special medical fabric and supported by a strong metallic frame. When it reaches the weakened area of the aneurysm, the system is deployed like an umbrella. The fabric-covered stent attaches firmly to the healthy vessel tissue, creating a new and durable channel for blood flow. Blood now flows through this newly created system, relieving the weakened and ballooned tissue outside from pressure and eliminating the risk of rupture.

In Which Situations Is Arterial Embolization Performed?

Interventional medicine not only opens blocked vessels but also has the ability to intentionally block certain vessels to stop bleeding or deprive diseased tissues of nutrients. This procedure is called embolization. The principle is simple: cut off the energy supply of the problematic tissue.

Common conditions where this treatment is used include:

• Fibroids
• Enlarged prostate
• Bleeding
• Tumors
• Aneurysms

For example, uterine fibroids, which are very common in women and can cause severe bleeding, were previously treated by removing the uterus. Today, the arteries supplying the fibroid are identified and intentionally blocked by injecting tiny particles. As the fibroid is deprived of blood supply, it gradually shrinks, allowing the woman to both relieve symptoms and preserve her uterus. Similarly, in men with benign prostate enlargement, blocking the arteries supplying the prostate leads to shrinkage of the gland and relief of urinary symptoms. Additionally, in life-threatening internal bleeding in areas such as the stomach, intestines, or lungs, identifying and blocking the bleeding vessel within seconds can be truly life-saving.

How Is a Clotted Artery Cleared?

In arteries suddenly blocked by clots, every second counts. Blood-thinning medications administered through an IV alone are not sufficient to dissolve large and hard clots. At this point, pharmacomechanical treatments come into play. The physician reaches the very center of the clot via a catheter in the angiography unit.

Powerful clot-dissolving drugs are injected directly into the core of the clot under pressure, maximizing their effectiveness. At the same time, special medical devices are used to mechanically break up the clot or create a strong suction effect to remove it from the vessel like a vacuum cleaner. Especially in leg blockages or stroke involving brain vessels, these direct interventions performed in the early hours or days can prevent tissue death, reduce the risk of amputation to nearly zero, and enable the patient to fully recover.

What Tests Are Performed Before Arterial Procedures?

To safely perform all these advanced interventions, a detailed analysis of the patient’s condition is essential beforehand. During angiography procedures, a contrast agent is injected into the blood to visualize the vessels. This substance is later filtered and excreted by the kidneys.

The primary parameters required for procedural safety are:

• Creatinine
• Urea
• Platelet
• INR

Blood tests are evaluated to ensure that the kidneys can safely perform this filtration function. Additionally, since the vessel will be intervened upon during the procedure, the patient’s blood clotting times and bleeding risk are assessed. If necessary, medications the patient is taking may be temporarily discontinued or adjusted under medical supervision before the procedure.

What Should Be Considered for Arterial Health After the Procedure?

Once the procedure is completed and the patient is taken to bed, the recovery process begins. After removing the plastic sheath from the groin or wrist where access was gained, pressure is applied manually or with special devices for a certain period to prevent bleeding. In some cases, the small puncture in the vessel can be closed immediately with special closure devices.

It is very important for the patient to lie flat on their back for several hours without getting up to ensure proper healing of the area. For the first few days after discharge, heavy lifting should be avoided, caution should be taken when climbing stairs, and physical activities that may strain the area should be avoided. However, the most critical point is the strict adherence to the blood-thinning medications prescribed by the doctor to ensure that the stents placed in the vessel function properly for many years.

What Should Be Done to Prevent Arterial Diseases in the Future?

It should not be forgotten that successfully opening a blocked vessel with advanced technology does not mean the disease will never return. If the lifestyle factors that caused the blockage continue, the disease may recur in another vessel or in a different part of the same vessel. Arterial health is a reflection of overall health, and maintaining it is entirely in your hands.

Essential habits for healthy arteries include:

• Exercise
• Diet
• Weight
• Control

If you smoke, it should be completely eliminated from your life immediately. A diet low in saturated fats and rich in olive oil, vegetables, fresh fruits, and whole grains should be adopted. Regular brisk walking is one of the most effective ways to maintain arterial elasticity. If you have high blood pressure or diabetes, these conditions must be kept under control.

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