Aorta: Anatomy, Function, and Symptoms of an Aortic Problem

The aorta is the largest blood vessel in the body, carrying oxygen-rich blood from the heart to every organ and tissue. It begins at the left ventricle, extends upward through the chest to form an arch, and continues downward, eventually branching into the iliac arteries just above the pelvis. Divided into four sections—the aortic root, ascending aorta, aortic arch, and descending aorta—it ensures blood reaches areas like the arms, legs, brain, and abdominal organs.

Signs of a problem with the aorta can include severe chest or back pain, shortness of breath, a pulsing feeling in the abdomen, or fainting. Aortic issues, such as aneurysms, are often detected with imaging tests such as ultrasounds and CT scans. To protect the aorta, a balanced diet, regular exercise, and managing blood pressure and cholesterol levels are essential. Quitting smoking is also critical, as smoking greatly increases the risk of aortic conditions like aneurysms.

Aorta Anatomy

The aorta is the largest artery in the body to which all other major arteries are connected. It is a big tube-like structure, usually about 1 inch wide in diameter, although its size varies proportionally to the height and weight of the person.

The aorta is widest at the point where it connects to the heart's left ventricle through the aortic valve; then, it gets progressively narrower as it descends into the abdomen.

The aorta is divided into four parts:

• Ascending aorta: The ascending aorta is the first section of the aorta, connected to the left ventricle, which pumps oxygenated blood to the body. It begins at the aortic valve, which regulates blood flow from the heart into the aorta.
• Aortic arch: This is the part of the aorta that curves upward toward the head and neck. It starts where the ascending aorta ends.
• Descending aorta: This is the part of the aorta that travels downward from the aortic arch through the chest. It is also known as descending thoracic aorta or simply thoracic aorta.
• Abdominal aorta: This is the final part of the aorta. It starts at your diaphragm and ends where the aorta splits off into the two arteries (iliac arteries) that extend into the legs.

The aorta also has three layers in its wall:

• The tunica intima is the inner layer. This layer is a smooth surface where the blood flows. It is thin and made of endothelial cells and supporting tissue.
• The tunica media is the middle layer. This layer is made of smooth muscle, elastic tissue, and collagen.
• The tunica adventitia is the outer layer. This layer is made of connective tissue like collagen and a network of small blood vessels (known as vasa vasorum), which functions to nourish the aorta.

Anatomical Variations

Certain congenital conditions affect the position, structure, or function of the aorta, including:

• Dextrocardia: In people with dextrocardia, the heart is located on the right side of the chest instead of the left, often causing the aorta to also be positioned on the right. This positioning doesn't usually affect heart function on its own but may occur alongside other heart abnormalities that require monitoring.
• Situs inversus: In situs inversus, all major organs are mirrored from their usual positions, with the aorta located on the right. This mirror-image arrangement is generally harmless but can sometimes be linked to other heart or organ issues.
• Coarctation of the aorta: This birth defect causes a narrowing of the aorta, typically just after the arteries that supply the head and arms. The narrowed segment restricts blood flow, leading to high blood pressure and potential heart damage if not corrected, often requiring surgical intervention.
• Bicuspid aortic valve: Instead of the usual three leaflets, a bicuspid aortic valve has only two, which can cause blood flow issues over time. Commonly found alongside coarctation of the aorta, this condition may lead to aortic stenosis or aortic regurgitation in adulthood if left untreated.

Most aortic birth defects, when detected early and managed appropriately, can be corrected to prevent long-term health effects.

Function

The main function of the aorta is to supply blood to almost all the major organs in the body through the smaller arteries that arise from it.

Broken down, the function of the different parts of the aorta include:

• Ascending aorta: This part of the aorta connects to the aortic valve and it collects oxygenated blood from the left ventricle of the heart. It also gives rise to the left and right coronary arteries which supply blood to the heart.
• Aortic arch: The aortic arch gives rise to the right common carotid and right subclavian arteries (via the brachiocephalic trunk), supplying blood to the right side of the head, neck, and right arm. The left common carotid and left subclavian arteries branch directly from the arch, supplying the left side of the head, neck, and left arm.
• Descending aorta: This part has many smaller arteries branching out from it that supply blood to the esophagus, pericardium, the top part of the diaphragm, lymph nodes, ribs, and some other structures in the chest.
• Abdominal aorta: This final part of the aorta gives rise to the largest number of arteries. The arteries branching out from it supply the liver, diaphragm, stomach, spleen, abdominal esophagus, intestines, kidneys, spinal cord, and pancreas. It also gives rise to the iliac arteries which then supply the legs, gluteal muscles, and the organs in the pelvic area.

Aortic Problems

There are several conditions with serious complications that center around or affect the aorta:

Aortic aneurysm: An aortic aneurysm is a bulge in the wall of the aorta. It is a serious condition because if the aorta ruptures at that spot, it can lead to life-threatening severe internal bleeding and other serious complications.

Aortic atherosclerosis: This occurs when plaque (made up of substances like cholesterol and calcium) collects and hardens inside the aorta blocking the free flow of blood through it and weakening the aortic walls. It can lead to aortic aneurysms, arterial thrombosis, strokes, and anginas.

Aortic dissection: This occurs when blood flows between the inner and middle layers of the aortic wall through a tear in the inner layer. This causes the layers to separate (dissect). It is typically caused by atherosclerosis, hypertension, connective tissue disorders, and injuries. It is a very dangerous condition and can lead to aortic regurgitation, gastrointestinal bleeding, myocardial infarction, kidney failure, and pericardial effusion, and can be fatal.

Penetrating aortic ulcer: This is a chronic condition that’s very similar to aortic dissection but is usually considered a separate condition because the cause of dissection is not a tear in the wall. Instead, the cause is ulcers formed due to wear of the aortic wall which is caused by atherosclerosis.

Aortoenteric fistula (AEF): This is a rare condition in which an abnormal connection forms between the aorta and the bowel. It usually only occurs in patients who have had surgery to treat an aortic aneurysm in the past. It is a life-threatening condition that is difficult to diagnose. Its complications are infections and gastrointestinal bleeding.

Aortobronchial fistula (ABF): This is another rare condition where an abnormal connection forms between the aorta and the tracheobronchial tree—the structure that supplies air to the lungs. This condition usually occurs in people who have aortic aneurysms or have had a previous surgical graft to treat an aortic condition. Its major complication is hemoptysis, or coughing up blood or mucus mixed with blood.

Aortic stenosis: With this condition, the aortic valve doesn’t open completely when it should, making the heart have to pump harder to get blood through the valve and into the aorta. It can lead to complications like left ventricular hypertrophy (LVH), diastolic dysfunction, and diastolic heart failure.

Aortic regurgitation: This happens when the aortic valve doesn’t close properly, allowing blood to flow back into the heart’s left ventricle. Acute cases are often caused by infective endocarditis or aortic dissection in the ascending aorta. Chronic cases, which may be symptom-free for years, result from valve deterioration, thoracic aortic aneurysm, rheumatic fever, endocarditis, or trauma. This condition can lead to pulmonary edema, left ventricular hypertrophy, arrhythmias, and heart failure.

Aortitis: This is the inflammation of the aorta. It could be caused by a number of reasons like injury and infection. It can also be caused by conditions like giant cell arteritis and Takayasu arteritis (when the artery they affect is the aorta). Aortitis is rare, but it can lead to serious complications like heart failure and aortic aneurysms.

Symptoms of Aortic Problems

Symptoms of an aortic problem vary somewhat depending on the cause. Most people with an aortic aneurysm don't have symptoms unless the aneurysm expands or bursts.

Otherwise, possible symptoms of an aortic aneurysm might include:

• Difficult or painful swallowing
• Difficulty breathing
• Feeling full after not eating much
• Hoarseness
• Pain in the neck, jaw, back, chest, stomach area or shoulder
• A pulsating or throbbing feeling in your stomach area
• Shortness of breath
• Swelling of the face, neck, or arms

A ruptured aortic aneurysm may cause:

• Light-headedness
• Rapid heart rate
• Sudden, severe pain in the stomach area, chest, or back, often described as a tearing sensation
• Loss of consciousness
• Signs of shock, such as weak pulse, pale and clammy skin, and faintness
• Extreme drop in blood pressure

Many of these symptoms can be signs of other life-threatening conditions. See a healthcare provider immediately if you experience one or more of these symptoms.

Diagnosis

Diagnosis for aortic problems often involve one or more of the following tests and exams:

• Physical exam: A provider will check for physical signs and symptoms of an aortic problem, such as an unusual pulse, swelling, or signs of distress.
• Ultrasound: This non-invasive test uses sound waves to create images of the aorta. Your provider can use it to detect aneurysms and other abnormalities, especially in the abdominal area.
• Computed tomography (CT) scan: CT scans can provide detailed images of the aorta. Providers can use it to assess the size, shape, and condition of the aorta, and locate any blockages or tears.
• Magnetic resonance imaging (MRI): An MRI gives detailed images of the aorta as well. It is often used to evaluate problems related to the aorta's structure, such as aortic dissection.
• Echocardiogram: This test uses sound waves to create real-time images of the heart and aorta. It can be used to detect aortic valve problems or aortic enlargement.
• Angiogram: This test involves the use of contrast dye injected into the blood vessels, allowing X-rays to capture detailed images of the aorta and any possible aneurysms or blockages.

When diagnosed early, many aortic problems, including aortic aneurysm, can be monitored and successfully treated.

Keeping Your Aorta Healthy

Keeping your aorta healthy is crucial for overall cardiovascular health. Here are some key practices to maintain a healthy aorta:

• Manage blood pressure: High blood pressure weakens the walls of the aorta over time, increasing the risk of aneurysms and tears. Monitor your blood pressure regularly, take blood pressure medications as prescribed, and eat a heart-healthy diet to reduce strain on the aorta.
• Adopt a heart-healthy diet: Eat a diet rich in heart-healthy foods, like vegetables, whole grains, and healthy fats like olive oil and fatty fish. Cut down on salt and sugar intake and avoid saturated fats like those in fried and highly processed foods.
• Exercise regularly: Physical activity helps reduce blood pressure and protects your cardiovascular system. Aim for 30 minutes of aerobic exercise, like brisk walking, running, or swimming, at least five days a week.
• Quit smoking: Cigarette smoking is one of the biggest risk factors for cardiovascular disease and aortic problems. In fact, 75% of abdominal aortic aneurysm cases are in people who smoke. If you need help quitting, reach out to a healthcare provider to discuss options.
• Control cholesterol levels: A buildup of plaque due to high cholesterol causes increased inflammation in and around the aorta and other blood vessels, increasing the risk of aortic aneurysm, dissection, and other aortic conditions.
• Practice good oral hygiene: Gum disease is a little-known but significant risk factor for atherosclerosis and cardiovascular disease. Brush your teeth at least twice a day and floss daily to remove plaque and bacteria that can lead to gum disease.
• Maintain a healthy weight: People with overweight and obesity are at an increased risk of high blood pressure, heart disease, and other conditions that can affect the aorta. Maintain a healthy weight by eating a balanced diet and exercising regularly to lower your risk of these conditions.
• Limit alcohol consumption: Excessive drinking raises the risk of high blood pressure, arterial disease, and heart problems. The American Society of Hypertension recommends that men limit their alcohol consumption to no more than two drinks a day, and women to no more than one drink a day.

The U.S. Preventive Services Task Force recommends that men ages 65 to 75 who have ever smoked get an ultrasound screening for abdominal aortic aneurysms even if they have no symptoms.

If you have been diagnosed with an aortic disease, you can reduce your risk of complications by reporting any symptoms immediately and seeing a healthcare provider regularly for checkups.

Summary

The aorta is the largest blood vessel in the body, beginning at the left ventricle of the heart, arching through the chest, and extending down into the abdomen. Its primary function is to carry oxygen-rich blood from the heart to the body’s organs and tissues, branching into smaller arteries as it descends. Signs of an aortic problem can include chest or back pain, shortness of breath, a pulsating feeling in the abdomen, or sudden dizziness and should be addressed promptly.

Keeping your aorta healthy involves managing blood pressure, cholesterol, and lifestyle habits. Eating a balanced diet, exercising regularly, and quitting smoking can reduce the risk of conditions like aortic aneurysms and atherosclerosis. Limiting alcohol intake and maintaining a healthy weight also help protect the aorta from damage and ensure better heart health overall.