0:00 The aorta is the largest artery in the human body, and arguably one of the most 0:07 important. 0:10 It receives oxygen-rich blood from the left ventricle of the heart and supplies 0:14 it to 0:14 the body via the systemic circulation. 0:18 The aorta begins at the left ventricle and terminates at the level of L4 around 0:23 the level 0:24 of the umbilicus and supplies a number of major arteries and vital organs. 0:32 The aorta can be divided into four sections, the ascending aorta, the aortic 0:38 arch, the 0:38 thoracic or descending aorta, and the abdominal aorta. 0:43 The aorta terminates by bifurcating into the left and right common iliac 0:50 arteries. 0:51 Let's talk about the first part, called the ascending aorta. 0:56 The first section of the aorta is the ascending aorta. 0:59 It arises from the aortic orifice and ascends to become the aortic arch. 1:04 It is approximately two inches or five centimeters long and travels with the 1:10 pulmonary trunk 1:11 within the pericadio sheath. 1:15 The left and right aortic sinuses, also known as the sinuses of Valsalva are d 1:21 ilation in 1:22 the ascending aorta, located at the level of the aortic valve. 1:28 These sinuses give rise to the left and right coronary arteries that supply the 1:33 muscle of 1:34 the heart itself, the myocardium. 1:41 The next part of the aorta is the aortic arch, which is the continuation of the 1:47 ascending 1:48 aorta. 1:51 It begins at the level of the second sternocostal joint, and arches superiorly, 1:58 then posteriorly, 2:00 and to the left before moving inferiorly. 2:05 The aortic arch is approximately five centimeters long, and is connected to the 2:11 pulmonary trunk 2:12 by the ligamentum arteriosum, a remnant of the fetal ductus arteriosus, and 2:18 terminates 2:19 at the level of about T4 vertebrae. 2:27 There are three major branches which arise from the aortic arch. 2:32 All to distal these are the brachiocophallic trunk, the left common carotid 2:39 artery, and 2:40 the left subclavian artery. 2:42 The brachiocophallic trunk is the first and largest branch of the aortic arch. 2:46 It ascends laterally and splits into the right common carotid artery and the 2:50 right subclavian 2:51 artery. 2:52 These arteries supply the right side of the head and neck, and the right upper 2:56 limb. 2:57 The next branch is the left common carotid artery, it ascends up the neck and 3:00 supplies 3:01 the left side of the neck and head. 3:03 The third branch is the left subclavian artery, this supplies the left upper 3:10 limb. 3:11 Some clinical anatomy, a condition that can be found at the aortic arch is co-o 3:16 ctation 3:16 of the aorta. 3:18 It is a congenital condition that occurs when there is a narrowing of the aorta 3:23 , usually 3:23 at the insertion of the ligamentum arteriosum. 3:29 The narrowing of the vessel leads to increased resistance to blood flow, which 3:33 increases 3:34 the afterload, the pressure that the heart must over the work against to eject 3:39 blood. 3:40 This results in left ventricular hypertrophy. 3:43 As the co-octation is located distal to the vessels that supply the head, neck 3:48 and upper 3:49 limbs, blood supplying to those areas are not compromised. 3:55 On the other hand, blood supply to the lower limbs is reduced, resulting in 4:01 weakness of 4:02 the lower limbs, and a weak delayed femoral pulse, which presents clinically as 4:09 radio 4:10 femoral delay, which just means that there is a mismatch in timing when pulses 4:15 are felt 4:15 in the arms, the radial pulse compared to the femoral pulse. 4:22 Another aorta is a very important condition to catch, because without 4:26 intervention these 4:28 infants often do not survive past neonatal period. 4:33 Treatment for co-octation of the aorta depends on the age of diagnosis and the 4:37 severity of 4:37 the condition. 4:39 Common interventions are surgical, however balloon angioplasty and stenting may 4:43 be used 4:44 as first line. 4:49 The third part of the aorta is the thoracic aorta, descending aorta, which 4:54 continues 4:54 from the aortic arch, and spans from the level of T4 to T12. 5:01 Initially it begins to the left of the vertebral column, but approaches the mid 5:06 line as it descends. 5:08 It exits the thorax via the aortic hiatus in the diaphragm, where it becomes 5:13 the abdominal 5:14 aorta. 5:19 The branches of the thoracic aorta in descending order are the bronchial 5:25 arteries, mediastinal 5:28 arteries, esophageal arteries, pericardio arteries, the superior phrenic 5:35 arteries supplying 5:36 the superior diaphragm, and the intercostal and subcostal arteries, which are 5:42 paired 5:42 arteries that branch off throughout the length of the posterior thoracic aorta. 5:47 These are nine pairs of intercostal arteries. 5:55 The abdominal aorta is the last part of the aorta, and is the continuation of 6:00 the thoracic 6:01 aorta. 6:02 It begins at the level of the T12 vertebrae, and terminates at the level of L4 6:08 vertebrae. 6:09 At the L4 vertebrae, the aorta terminates by bifocating into the right and left 6:14 common 6:15 iliac arteries that supplies the lower limbs. 6:23 The branches of the abdominal aorta, there are many. 6:27 In descending order, these are the inferior phrenic arteries, that's apply the 6:32 diaphragm, 6:34 celiac trunk, superior mesenteric artery, middle super renal artery, renal 6:40 arteries, 6:41 gonadal arteries, inferior mesenteric artery, median sacral artery, and lumba 6:54 arteries. 6:57 The three anterior branches, the celiac trunk, the superior mesenteric artery, 7:03 and the inferior 7:04 mesenteric artery of the abdominal aorta are very important, as they supply the 7:09 gastrointestinal 7:10 tract. 7:11 In summary, the celiac trunk supplies the fore gut, the superior mesenteric 7:16 artery supplies 7:17 the mid gut, and the inferior mesenteric artery supplies the hind gut. 7:27 Some clinical anatomy, aortic dissection. 7:31 An aortic dissection is a serious condition, which occurs when there is injury 7:35 in the inner 7:35 most wall, known as the tunica intima of the aorta. 7:39 This tear creates two channels for blood flow. 7:42 The first is the normal lumen of the aorta, and the other is into the wall 7:49 where blood 7:50 remains stationary. 7:52 You can imagine the blood that remains in the wall can result in constriction 7:57 of the 7:57 aortic lumen, leading to a reduction of blood flow to the rest of the body. 8:05 Aortic dissection is a medical emergency, and can quickly result in death due 8:10 to insufficient 8:11 blood flow to the heart or complete rupture of the aorta. 8:16 Aortic dissection can occur anywhere along the aorta, but the most common site 8:19 is the 8:20 beginning of the ascending aorta. 8:26 Patients with an aortic dissection will classically present with a tearing 8:30 chest pain, which radiates 8:32 through to the back, other symptoms arise due to decreased blood supply to 8:36 other organs, 8:37 such as stroke or mesenteric ischemia. 8:40 Other causes of aortic dissection include chronic hypertension, a weakened aort 8:45 ic wall 8:45 can be due to malfan syndrome, or an aortic aneurysm, which we will talk about 8:54 next. 8:55 The current gold standard first-line investigation for an aortic dissection is 9:00 a CT angiogram. 9:02 However, MRI angiograms, so MRA, and transisophageal echocardiogram can also be 9:13 used. 9:14 Treatment for aortic dissection depends on the type of aortic dissection. 9:18 There's type A, which develops in the ascending aorta, whereas type B involves 9:25 a tear in the 9:26 descending part of the aorta and may extend to the abdomen. 9:30 Type A aortic dissection involves surgery, and here what happens is the surgeon 9:37 will 9:37 remove as much of the dissected aorta as possible in order to stop blood from 9:42 leaking 9:42 into the aortic wall, and a graft is then used to reconstruct the aorta. 9:47 Medications are also used to reduce heart rate and lower blood pressure to 9:50 prevent worsening 9:51 of the dissection. 9:53 Similar management is for type B, but mainly for type B, it's medication. 10:00 Clinical anatomy, aortic aneurysm. 10:12 An aortic aneurysm is a balloon-like bulge or dilation of the aorta, to more 10:18 than 50% 10:19 times its normal diameter. 10:22 Aortic aneurysm can occur anywhere in your aorta, however the most common site 10:27 for aneurysmal 10:28 changes is the abdominal aorta. 10:30 This is known as triple A, which is the abdominal aortic aneurysm. 10:39 Aortic aneurysms can arise because of an underlying weakness of the vessel 10:43 walls such 10:43 as in Marfan syndrome, or they can be due to pathological processes such as an 10:49 aortic 10:49 dissection. 10:52 An ultrasound is used for diagnosis, and treatment involves surgical 10:56 replacement of the weak 10:58 and vessel wall with a piece of synthetic tubing. 11:07 Aortic aneurysms that are small usually do not present immediate threat, 11:11 however if left 11:12 untreated, a large aneurysm can rupture. 11:15 This is a medical emergency and is often fatal. 11:19 Pations who have an abdominal aortic aneurysms may experience back pain, 11:24 abdominal pain and 11:25 abdominal pulsations. 11:28 It is also possible that the aneurysm can result in compression of the nerve 11:32 root causing 11:33 pain and numbness in the lower limbs. 11:37 Patients who have an aortic arch aneurysm may have a horse voice due to 11:42 involvement of 11:43 the left recurrent laryngeal nerve which wraps around the aortic arch. 11:48 However, it is possible for patients to not present with any symptoms at all. 11:58 In summary, this video we talked about the different parts of the aorta, the 12:03 ascending 12:03 aorta, the aortic arch, the thoracic or descending aorta and finally the 12:08 abdominal aorta and 12:10 their branches. 12:11 We also discussed three clinical conditions, the aortic coactation which 12:16 affects the aortic 12:17 arch, the aortic dissection which mostly affects the ascending aorta and the a 12:24 ortic 12:24 aneurysm which most commonly affects the abdominal aorta. 12:28 Thank you for watching.
