La anatomía de la aorta

La aorta es la arteria más grande del cuerpo. Transfiere sangre llena de oxígeno desde el corazón a diferentes órganos del cuerpo. La aorta comienza en el ventrículo izquierdo del corazón, se arquea hacia arriba hacia el cuello, luego se curva hacia abajo y se extiende hacia el abdomen. Obtenga más información sobre el importante papel que desempeña la aorta en el cuerpo.

Anatomía

Estructura

La aorta es la arteria más grande del cuerpo a la que están conectadas todas las demás arterias principales. Es una estructura grande similar a un tubo, generalmente de aproximadamente 1 pulgada de diámetro, aunque su tamaño varía proporcionalmente a la altura y el peso de la persona. La aorta es más ancha en el punto donde se conecta con el ventrículo izquierdo del corazón a través de la válvula aórtica; luego, se vuelve progresivamente más estrecho a medida que desciende hacia el abdomen.

Cuatro partes de la aorta

  • La aorta ascendente
  • Arco aórtico
  • Aorta descendente
  • Abdominal aorta

La aorta se divide en cuatro partes:

  • Ascending aorta: This is the first part of the aorta and it is connected to the left ventricle of the heart (the part that pumps oxygenated blood to the body’s tissues and organs). The ascending aorta starts at the aortic valve which closes and opens to stop and allow the flow of blood 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 of 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 on. 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) whose function is to nourish the aorta.

Location

The aorta is located at different parts of the body. It starts at the heart’s left ventricle, goes through the chest, and ends at the lower abdomen.

Anatomical Variations

For people that have dextrocardia (a condition where the heart is located on the right side of the body), the aorta is usually on the right side instead of on the left side. The same applies to people who have a condition called situs invertus, where all the organs are on the opposite side of where they usually are—like a mirror image.

There is a birth defect known as coarctation of the aorta, in which a part of the aorta is significantly narrower than it ordinarily should be. The narrowing is usually found right after the arteries that supply blood to the head and arms have arisen from the aorta. This narrowing occurs when the baby’s aorta doesn’t form properly while it’s in the womb and its effect is that it doesn’t let blood to flow to the body properly. This variation causes high blood pressure and eventual heart damage if it’s not corrected.

There is a common birth defect where babies are born with what is known as a bicuspid aortic valve. Usually, the aortic valve has three leaflets or “cups” through which blood passes into the aorta. With a bicuspid aortic valve, there are only two. This condition is often found in babies born with coarctation of the aorta, too. A bicuspid aortic valve can lead to conditions like aortic stenosis and aortic regurgitation later in adulthood if it’s not surgically corrected.

While birth defects involving the aorta can cause various health issues, for the most part, when caught and corrected, they won’t cause negative 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 are:

  • 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: This part gives rise to the right common carotid artery and the right subclavian artery (protruding from the brachiocephalic trunk) which supply blood to the right side of the head and neck and the right arm respectively. The left common carotid artery and the left subclavian artery which supply blood to the left side of the head and neck and the left arm respectively also branch off from the aortic arch.
  • 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.

Clinical Significance

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

Aortic aneurysm: An aortic aneurysm is a weakened point on the aorta. It occurs when the aorta is not able to contract and expand to accommodate the passage of blood properly. It is a serious condition because if the aorta ruptures at that spot, it can lead to severe internal bleeding and other serious complications.

Aortic atherosclerosis: This is 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 is 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) and 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.

Penetrando Ulce aórtica r : Esta es una condición crónica que es muy similar a la disección aórtica pero por lo general se considera una condición separada debido a que la causa de la disección no es un desgarro en la pared. En cambio, la causa es la formación de úlceras debido al desgaste de la pared aórtica causada por la aterosclerosis.

Fístula aortoentérica (AEF): esta es una condición rara en la que se forma una conexión anormal entre la aorta y el intestino. Por lo general, solo ocurre en pacientes que se sometieron a una cirugía para tratar un aneurisma aórtico en el pasado. Es una afección potencialmente mortal que es difícil de diagnosticar. Sus complicaciones son infecciones y hemorragias gastrointestinales.

Fístula aortobronquial (ABF, por sus siglas en inglés): esta es otra condición rara en la que se forma una conexión anormal entre la aorta y el árbol traqueobronquial, la estructura que suministra aire a los pulmones. Esta afección generalmente ocurre en personas que tienen aneurismas aórticos o que han tenido un injerto quirúrgico previo para tratar una afección aórtica. Su principal complicación es la hemoptisis , o tos con sangre o moco mezclado con sangre.

Estenosis aórtica: con esta condición, la válvula aórtica no se abre completamente cuando debería, lo que hace que el corazón tenga que bombear con más fuerza para que la sangre pase a través de la válvula y penetre en la aorta. Puede llevar a complicaciones como hipertrofia ventricular izquierda (LVH), disfunción diastólica e insuficiencia cardíaca diastólica.

Regurgitación aórtica: esto ocurre cuando la válvula aórtica no se cierra correctamente y, por lo tanto, permite que la sangre regrese al ventrículo izquierdo del corazón. Su forma aguda es causada por endocarditis infecciosa y disección aórtica en la parte ascendente. La forma crónica, que por lo general no muestra síntomas durante mucho tiempo, es causada por el deterioro de la válvula aórtica, el aneurisma en la aorta torácica, la fiebre reumática, la endocarditis infecciosa y el traumatismo. Puede conducir a edemas pulmonares, hipertrofia ventricular izquierda (LVH), arritmias e insuficiencia cardíaca. También se conoce como insuficiencia aórtica.

Aortitis: esta es la inflamación de la aorta. Podría ser causada por una serie de razones como lesiones e infecciones. También puede ser causada por afecciones como la arteritis de células gigantes y la arteritis de Takayasu (cuando la arteria que afectan es la aorta). La aortitis es rara, pero puede provocar complicaciones graves como insuficiencia cardíaca y aneurismas aórticos.

I am Dr. Christopher Loynes and I specialize in Bone Marrow Transplantation, Hematologic Neoplasms, and Leukemia. I graduated from the American University of Beirut, Beirut. I work at New York Bone Marrow Transplantation
Hospital and Hematologic Neoplasms. I am also the Faculty of Medicine at the American University of New York.