Descending thoracic aorta

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Thoracic aorta
Aorta segments.svg
Schematic view of aorta and its segments, with Descending thoracic aorta labeled near middle
Gray530.png
The thoracic aorta, viewed from the left side.
Details
Source descending aorta
Branches bronchial arteries, esophageal arteries, posterior intercostal arteries, abdominal aorta, superior phrenic artery, pericardial arteries
Identifiers
Latin pars thoracica aortae, aorta thoracalis
MeSH D001013
TA98 A12.2.11.001
TA2 4186
FMA 3786
Anatomical terminology

The descending thoracic aorta is a part of the aorta located in the thorax. It is a continuation of the aortic arch. It is located within the posterior mediastinal cavity, but frequently bulges into the left pleural cavity. The descending thoracic aorta begins at the lower border of the fourth thoracic vertebra and ends in front of the lower border of the twelfth thoracic vertebra, at the aortic hiatus in the diaphragm where it becomes the abdominal aorta.

Contents

At its commencement, it is situated on the left of the vertebral column; it approaches the median line as it descends; and, at its termination, lies directly in front of the column.

The descending thoracic aorta has a curved shape that faces forward, and has small branches. It has a radius of approximately 1.16 cm. [1]

Structure

The descending thoracic aorta is part of the aorta, which has different parts named according to their structure or location. The descending thoracic aorta is a continuation of the descending aorta and becomes the abdominal aorta when it passes through the diaphragm. The initial part of the aorta, the ascending aorta, rises out of the left ventricle, from which it is separated by the aortic valve. The two coronary arteries of the heart arise from the aortic root, just above the cusps of the aortic valve. The aorta then arches back over the right pulmonary artery. Three vessels come out of the aortic arch: the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. These vessels supply blood to the head, neck, thorax and upper limbs.

Behind the descending thoracic aorta is the vertebral column and the hemiazygos vein. To the right is the azygos veins and thoracic duct, and to the left is the left pleura and lung. In front of the descending thoracic aorta lies the root of the left lung, the pericardium, the esophagus, and the diaphragm.

The esophagus, which is covered by a nerve plexus lies to the right of the descending thoracic aorta. Lower, the esophagus passes in front of the aorta, and ultimately is situated on the left.

Function

The aorta is an artery that conveys oxygenated blood from the heart to other parts of the body. It is one of the largest arteries in the body. [2] The aorta gives off several paired branches as it descends. In descending order, these include the

Note: The posterior intercostal arteries are branches that originate throughout the length of the posterior aspect of the descending thoracic aorta.

Clinical significance

Histopathological image of dissecting aneurysm of descending thoracic aorta in a patient without evidence of Marfan's trait. The damaged aorta was surgically removed and replaced by artificial vessel. Victoria blue & HE stain. Aortic dissection (1) Victoria blue-HE.jpg
Histopathological image of dissecting aneurysm of descending thoracic aorta in a patient without evidence of Marfan's trait. The damaged aorta was surgically removed and replaced by artificial vessel. Victoria blue & HE stain.

Additional images

Related Research Articles

Aorta Largest artery in the human body

The aorta is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries. The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

Thoracic cavity Chamber of the body of vertebrates that is protected by the rib cage

The thoracic cavity is the chamber of the body of vertebrates that is protected by the thoracic wall. The central compartment of the thoracic cavity is the mediastinum. There are two openings of the thoracic cavity, a superior thoracic aperture known as the thoracic inlet and a lower inferior thoracic aperture known as the thoracic outlet.

Inferior vena cava One of two veinous trunks bringing deoxygenated blood back to the heart

The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.

Subclavian artery Major arteries of the upper thorax, below the clavicle

In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.

Thoracic duct Lymphatic vessel

In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. It is also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal. The other duct is the right lymphatic duct. The thoracic duct carries chyle, a liquid containing both lymph and emulsified fats, rather than pure lymph. It also collects most of the lymph in the body other than from the right thorax, arm, head, and neck. The thoracic duct usually starts from the level of the twelfth thoracic vertebra (T12) and extends to the root of the neck. It drains into the systemic (blood) circulation at the junction of the left subclavian and internal jugular veins, at the commencement of the brachiocephalic vein.

Thoracic diaphragm Sheet of internal skeletal muscle

The thoracic diaphragm, or simply the diaphragm, is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.

Pulmonary artery Artery in pulmonary circulation carrying deoxygenated blood from heart to lungs

A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.

Azygos vein

The azygos vein is a vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cava. It connects the systems of superior vena cava and inferior vena cava and can provide an alternative path for blood to the right atrium when either of the venae cavae is blocked.

Abdominal aorta

The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.

Mediastinum Central part of the thoracic cavity

The mediastinum is the central compartment of the thoracic cavity. Surrounded by loose connective tissue, it is an undelineated region that contains a group of structures within the thorax, namely the heart and its vessels, the esophagus, the trachea, the phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph nodes of the central chest.

Descending aorta

The descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or segments, the thoracic and the abdominal aorta, in correspondence with the two great cavities of the trunk in which it is situated. Within the abdomen, the descending aorta branches into the two common iliac arteries which serve the pelvis and eventually legs.

Bronchial artery

In human anatomy, the bronchial arteries supply the lungs with nutrition and oxygenated blood. Although there is much variation, there are usually two bronchial arteries that run to the left lung, and one to the right lung and are a vital part of the respiratory system.

Common carotid artery One of the two arteries that supply the head and neck with blood

In anatomy, the left and right common carotid arteries (carotids) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.

Aortic arch

The aortic arch, arch of the aorta, or transverse aortic arch is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea.

Hemiazygos vein

The hemiazygos vein is a vein running superiorly in the lower thoracic region, just to the left side of the vertebral column.

Aortic hiatus Anatomical detail

The aortic hiatus is a hole in the diaphragm. It is the lowest and most posterior of the large apertures.

Intercostal arteries Arteries supplying the space between the ribs

The intercostal arteries are a group of arteries that supply the area between the ribs ("costae"), called the intercostal space. The highest intercostal artery is an artery in the human body that usually gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space. It usually arises from the costocervical trunk, which is a branch of the subclavian artery. Some anatomists may contend that there is no supreme intercostal artery, only a supreme intercostal vein.

Prevertebral fascia

The prevertebral fascia is a fascia in the neck.

Outline of human anatomy Overview of and topical guide to human anatomy

The following outline is provided as an overview of and topical guide to human anatomy:

Pulmonary pleurae Serous membrane that lines the wall of the thoracic cavity and the surface of the lung

The pulmonary pleurae are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls.

References

PD-icon.svgThis article incorporates text in the public domain from page 598 of the 20th edition of Gray's Anatomy (1918)

  1. Solutions to the Van der Pol Equation: a Model of Aortic Blood Flow
  2. "Aorta Anatomy". UF Health, University of Florida Health. 2013-08-08. Retrieved 2022-06-05.