Descending Aorta

What is the descending aorta?

Your descending aorta is the longest part of your aorta, which is the largest artery in your body. It carries oxygen-rich blood from your heart through your chest and abdomen (belly). It also branches off into smaller arteries in many places to supply blood to other parts of your body.

Descending thoracic aorta vs. descending abdominal aorta

Your descending aorta is one continuous artery that extends through your chest and belly. But its name changes depending on where it’s located. You can compare it to a street that changes names when it crosses from one town into another.

When your descending aorta passes through your chest, it’s called your descending thoracic aorta. “Thoracic” is a medical term for something that’s related to your thorax (your chest).

When your aorta reaches your diaphragm, it changes names. Below your diaphragm, it’s called your descending abdominal aorta. This is the part that travels through your upper belly and ends near your belly button.

Is the thoracic aorta the same as the descending aorta?

No, they’re not the same. Your thoracic aorta refers to the section of your aorta that travels through your chest. It includes several distinct parts:

• Aortic root: The part that attaches to your heart.
• Ascending aorta: The part that curves upward from your heart.
• Aortic arch: The curved part that gives your aorta a cane-like shape.
• Descending thoracic aorta: The part of your descending aorta that’s contained in your chest.

Your descending aorta refers to the part of your aorta that extends downward from your aortic arch. It travels through your chest (descending thoracic aorta) and your belly (descending abdominal aorta).

So, your thoracic aorta and your descending aorta aren’t the same. But your thoracic aorta includes part of your descending aorta.

What is the difference between the ascending and descending aorta?

Your ascending aorta curves upward from your heart and leads to the aortic arch. It’s located only in your chest. Your descending aorta curves downward on the other side of your aortic arch. It extends from your chest down into your belly.

What is the function of the descending aorta?

Your descending aorta plays a vital role in supplying your body with oxygen-rich blood. It’s the main artery that carries blood through your chest and belly. Many smaller arteries branch from your descending aorta to carry blood to your organs and tissues.

Your descending aorta and its branches supply blood to your:

• Chest wall.
• Digestive system (esophagus, stomach and small and large intestines).
• Kidneys.
• Legs.
• Lymph nodes.
• Reproductive organs (testes or ovaries).
• Respiratory tract.
• Spinal cord.
• Urinary tract.

Where is the descending aorta located?

Your descending aorta begins in your chest at the end of your aortic arch. It starts just after the point where your left subclavian artery branches from your aorta. This is around the level of your fourth thoracic vertebra (spinal bone), midway down your spine. From there, it travels down through your chest and diaphragm, then into your belly.

Your descending aorta ends near your belly button. There, it splits into two arteries called your right and left common iliac arteries. Scientists call this intersection (which looks like an upside-down Y) the aortic bifurcation. That’s because your aorta splits into two new paths for blood flow. Your common iliac arteries then split into other branches that supply blood to your legs and feet.

What are the branches of the descending aorta?

Your descending aorta has many branches that supply blood to different parts of your body.

Branches of your descending thoracic aorta (in your chest) include:

• Bronchial arteries.
• Esophageal arteries.
• Mediastinal arteries.
• Pericardial arteries.
• Superior phrenic arteries.

Branches of your descending abdominal aorta (in your belly) include:

• Celiac trunk arteries.
• Gonadal arteries.
• Iliac arteries.
• Inferior phrenic arteries.
• Left and right renal arteries.
• Lumbar arteries.
• Median sacral arteries.
• Middle suprarenal arteries.
• Superior and inferior mesenteric arteries.

What does the descending aorta look like?

The entire aorta is a cane-shaped artery. It begins with the ascending aorta and aortic arch, which form the cane’s handle. The descending aorta is the first straight segment of the aorta, beginning right after the arch.

How big is the descending aorta?

The diameter of your aorta varies based on your age, body surface area and sex assigned at birth. But researchers agree these are the normal values:

• Normal thoracic descending aorta size: Less than 1.6 centimeters/square meters of body surface area.
• Normal abdominal descending aorta size: Less than 3 centimeters (approximately 2 centimeters).

What are the layers of the descending aorta?

The descending aorta has three layers of tissue:

• Tunica intima: This is the inner layer through which your blood flows. It regulates blood pressure, prevents blood clots and keeps toxins out of your blood.
• Media: This is the middle layer that helps move your blood in one direction through contractions of small muscles in its wall. It also contains elastic fibers that can wear out over time.
• Adventitia: This is the outer layer that provides support and structure for your aorta. It also connects with nearby nerves and tissues.

What conditions and disorders affect the descending aorta?

Aortic aneurysms are the most common condition affecting the descending aorta. An aneurysm is a bulge or swelling in an artery, resulting from a weak spot in the artery’s wall. Types of aneurysms that can affect your descending aorta include:

• Thoracic aortic aneurysm (TAA): This is a bulge in the upper part of your aorta that runs through your chest. High blood pressure or injury to your chest are the most common causes. Some connective tissue disorders (like Marfan syndrome) also raise your risk.
• Abdominal aortic aneurysm (AAA): This is the most common type of aortic aneurysm. It’s a bulge in the part of your aorta that runs through your belly. AAAs usually affect people over age 65. They’re more common in people assigned male at birth (AMAB), especially those with a history of tobacco use. Atherosclerosis is the most common cause.
• Thoracoabdominal aortic aneurysm (TAAA): This is an aneurysm that extends from your chest into your belly.

If you have an aneurysm in your descending aorta, your healthcare provider will monitor it over time. If it grows too large, you may need treatment to prevent a life-threatening complication, such as:

• Aneurysm rupture: A hole in the wall of your aorta (all three layers). This hole can quickly lead to life-threatening internal bleeding.
• Type B aortic dissection: A tear in the inner layer of your descending aorta. Blood fills the space between your inner and middle artery layers. This can lead to a rupture or lack of blood flow to some of your organs.

Aneurysm ruptures and aortic dissections need immediate medical attention.

Other conditions that may affect your descending aorta include:

• Atherosclerosis of the aorta: Plaque buildup throughout your aorta.
• Aortoiliac occlusive disease: Plaque buildup in the lowest part of your aorta (near the aortic bifurcation) and your iliac arteries.

What are common symptoms of descending aorta conditions?

It’s essential to know that descending aorta conditions may cause no symptoms. So, you may not know anything’s wrong until you have a medical emergency. That’s why it’s important to visit your healthcare provider for regular checkups so your provider can notice early signs of aortic disease.

An aneurysm in your descending aorta may not cause symptoms until it’s close to rupturing. Warning signs before a rupture can include:

• Feeling full when you haven’t eaten a lot.
• Pain in your back, butt, groin, leg or belly that doesn’t go away.
• Pulsing sensation in your belly that feels like a heartbeat.
• Trouble breathing or shortness of breath.

An aneurysm rupture or dissection is a medical emergency. Call 911 or your local emergency number if you experience these symptoms:

• Sudden, severe pain in your belly.
• Sudden, sharp, severe pain in your chest or upper back. This may feel like a tearing, stabbing or ripping feeling.
• Clammy or very sweaty skin.
• Confusion.
• Dizziness or fainting.
• Fast heartbeat.
• Nausea and vomiting.
• Shortness of breath.
• Trouble talking.
• Vision loss.
• Weakness or paralysis on one side of your body.

What tests diagnose descending aorta conditions?

Healthcare providers diagnose descending aorta conditions through imaging tests. These may include:

• Abdominal ultrasound.
• Computed tomography angiography (CTA).
• Magnetic resonance imaging (MRI).
• Transesophageal echocardiogram.

What are common treatments for descending aorta conditions?

Your healthcare provider will monitor your condition and recommend treatment if needed. Treatment options for aneurysms in your descending aorta include:

• Aneurysm surgery.
• Endovascular aneurysm repair (EVAR).
• Medications to help slow aneurysm growth. These include medications that lower your blood pressure or manage your cholesterol.

How can I keep my descending aorta healthy?

You may be able to prevent or delay aortic disease by adopting a heart-healthy lifestyle. Tips include:

• Drink less alcohol. People assigned male at birth should have no more than two drinks per day. People assigned female at birth (AFAB) should have no more than one drink per day.
• Eat a healthy, balanced diet low in sodium, cholesterol and saturated fats.
• Exercise regularly. Aim for 150 minutes of moderate-intensity exercise per week.
• Manage stress.
• Quit smoking and using tobacco products.

A note from Cleveland Clinic

Your descending aorta plays a vital role in helping blood flow throughout your body. That’s why it’s important to do whatever you can to keep your aorta healthy. Eating a heart-healthy diet, exercising and avoiding tobacco products can help you avoid aortic disease. It’s also important to visit your healthcare provider for yearly checkups.