Circulatory System || Understanding the Anatomy of the Thoracic and Abdominal Circulation

You see, circulation in the thoracic and abdominal region begins with the Thoracic aorta which is the large vesicle superior to the diaphragm. It is part of the descending aorta and let's not forget that the aorta is an artery, it is just a large artery. It is coming off the descending aorta, and from the Thoracic aorta, there are a number of arteries that branches the Thoracic Aorta. One goes through the ribs, therefore, being referred to as an Intercostal artery and since one goes through the posterior axis, it is referred to as the Posterior Intercostal arteries, supplying the internal and external regions of the rib. The Thoracic aorta has another branch that supplies the diaphragm, this artery is superior to the diaphragm. It is known as the Superior Phrenic Artery. Also from the thoracic aorta is the Bronchial artery which supplies the bronchi of the lungs, the Esophageal artery, Another artery that supplies the mediastinum which houses the heart in the thorax, and supplies the lymphatic structures is known as the mediastinal artery. Also, the Pericardial artery which supplies the fibrous pericardium is also another branch of the thoracic aorta.^{, , , ,}

At the abdominal region, where the aorta goes down, the aorta becomes the abdominal aorta. As expected, if the thoracic arteries will supply the superior, then possibly the abdominal arteries should supply the inferior aspect of organs like the diaphragm. So the Inferior Phrenic artery supplies the lower part of the diaphragm but also supplies other organs like the stomach, the liver, the esophagus, and the inferior vena cava.^, The adrenal glands are also supplied by a branch from the abdominal artery known as the Supra renal artery, also the Renal arteries are another branch from the abdominal aorta which such supplies the kidneys. The Gonadal Arteries (testicular artery in males and ovarian artery in females) are also another branch of the abdominal aorta which supplies the reproductive organs. The abdominal aorta also braches to give the Celiac trunk/artery which branches to give the left gastric artery which supplies the stomach, the spleenic artery which also branches to supply the greater omentum of the stomach known as the Gastroepiploic artery, and also the gastroduodenal artery which supplies the pylorus and the duodenum. The gastroduodenal artery supplies the superior pancreatic duodenal artery which supplies the pancreas. The abdominal aorta branches to the Superior mesenteric artery which then splits into many branches which include the intestinal artery which supplies the jejunum and the ileum. The Superior mesenteric artery still splits into another artery known as the Ileocolic artery which supplies the ileum, caecum, and appendix. Also, the right colic artery is a branch that supplies the ascending colon. The transverse colon is supplied by the middle colic artery and it is a branch of the Superior mesenteric artery.^{, , ,} The inferior mesenteric artery is another branch of the Abdominal aorta and its branches into the left colic artery, sigmoid artery, and the Superior rectal artery which gives out two branches which are the mid rectal artery and the inferior rectal artery which supplies the rectum.,

From the abdominal aorta are arteries that supply the lumbar region of the body known as the Lumbar artery. From the abdominal aorta, towards the splitting is the left Common iliac artery which then branches into the left external iliac artery, and the left internal iliac artery.^{, ,} The internal iliac artery splits to give the Superior Gluteal artery which supplies the Gluteus maximus muscle the gluteus medius and the gluteus minimus, ^, Inferior to the Gluteal artery is the inferior gluteal artery which supplies the Gluteus maximus, the Quadratus femoris, Piriformis muscle, ischiococcygeus, and iliococcygeus. The inferior gluteal artery also branches to the internal pudendal artery which supplies the external genitalia and the Perineum. Also, the internal iliac artery supplies the Obturator artery which supplies the medial compartment of the thigh and the kneecap. The right common iliac artery is the second branch of the abdominal aorta also branches out to the right external iliac artery and the right internal iliac artery^{, , ,}

While the descending aorta which includes the thoracic aorta, the abdominal aorta, and the iliac arteries supplies oxygenated blood to the body and the lower part of the body but this aorta supply can be distorted as a result of a condition that is an autosomal dominant disorder which is as a result of a mutation of fibrillin gene Marfan Syndrome. Fibrillin is responsible for the elasticity of the blood vessels but when the gene is mutated, the elasticity of the vessels begins to decrease affecting the ability to withhold pressure and can lead to rupturing, and aneurysms, which would cause hypovolemic shock.^,

Image 1 || Wikimedia Commons || Thoracic Abdominal Arteries

Image 2 || Wikimedia Commons || Thoracic Abdominal Veins