Q. What do you mean by Descending Aorta?

 The descending aorta begins at the level of the fourth thoracic vertebra. It is defined through the cardiac shadow on the CXR, as it lies on the anterior aspect of the thoracic vertebral bodies, just to the left of the midline. Lengthening with age may also affect this portion of the aorta, which may resemble an aneurysm. A tortuous aorta may lie to the right of the spine. In systemic hypertension, the ascending aorta and arch may be dilated. Post stenotic dilatation of the ascending aorta is seen in aortic stenosis. More diffuse dilatation of the ascending limb, arch and descending aorta is usually seen in aortic regurgitation. A small aortic knuckle may be seen in ASD, severe mitral stenosis and supravalvar stenosis.