BRS Thorax HY 3 Flashcards
The mediastinum
The mediastinum is an interpleural space and consists of the superior mediastinum and inferior
mediastinum. The inferior mediastinum further divides into the anterior, middle, and posterior
mediastina.
The middle mediastinum contains
the heart
The posterior mediastinum contains
the esophagus,
thoracic aorta, azygos and hemiazygos veins, thoracic duct, vagus nerves, and sympathetic
splanchnic nerves.
Achalasia
Achalasia is a condition of impaired esophageal contractions resulting from degeneration of
myenteric (Auerbach) plexus in the esophagus. The lower esophageal sphincter fails to relax
during swallowing.
Systemic sclerosis (scleroderma)
Systemic sclerosis (scleroderma) is a systemic collagen vascular disease and has clinical features of dysphagia for solids and liquids, severe heartburn, and esophageal stricture.
Coarctation of the aorta
Coarctation of the aorta occurs when the aorta is abnormally constricted just inferior to the ductus arteriosus, in which case an adequate collateral circulation develops before birth. Clinical signs include hypertension and/or heart failure. It causes (a) a characteristic rib notching and a high risk of cerebral hemorrhage;
(b) tortuous and enlarged blood vessels, especially the internal thoracic, intercostal, epigastric, and scapular arteries;
(c) an elevated blood pressure in the radial artery and decreased pressure in the femoral artery; and
(d) the femoral pulse to occur after the radial pulse
(normally the femoral pulse occurs slightly before the radial pulse).
Stellate block is
an injection of local anesthetic near the stellate ganglion by placing the tip of the
needle near the neck of the first rib. It produces a temporary interruption of sympathetic function
such as in a patient with excess vasoconstriction in the upper limb.
Injury to the recurrent laryngeal nerve
Injury to the recurrent laryngeal nerve may be caused by a bronchogenic or esophageal carcinoma,
enlargement of mediastinal lymph nodes, an aneurysm of the aortic arch, or thyroid and parathyroid surgeries, causing respiratory obstruction, hoarseness, or an inability to speak because of paralysis of the vocal cord.
Vagotomy
Vagotomy is transection of the vagus nerves at the lower portion of the esophagus in an attempt to reduce gastric secretion in the treatment of peptic ulcer.
The azygos vein
The azygos vein is formed by the union of the right ascending lumbar and right subcostal veins. Its lower end is connected to the IVC.
The azygos vein arches …
over the root of the right lung and empties into the SVC.
The hemiazygos vein
The hemiazygos vein is formed by the union of the left subcostal and ascending lumbar vein, receives the 9th, 10th, and 11th posterior intercostal veins, and enters the azygos vein. Its lower end is connected to the left renal vein.
The accessory hemiazygos vein receives
the fifth to eighth posterior intercostal veins and terminates in the azygos vein.
The superior intercostal vein
formed by the second, third, and fourth intercostal veins and drains into the azygos vein on the right and the brachiocephalic vein on the left.
The thoracic duct
The thoracic duct begins in the abdomen at the cisterna chyli, which is the dilated junction of the intestinal, lumbar, and descending intercostal trunks. It drains all parts of the body except the right head, neck, upper limb, and thorax, which are drained by the right lymphatic duct. It passes through the aortic opening of the diaphragm, ascends between the aorta and the azygos vein, and empties into the junction of the left internal jugular and subclavian veins.
