Thorax Flashcards
Describe the blood supply and lymphatic drainage of the oesophagus
Arterial supply:
–> upper 1/3rd: Inferior thyroid artery (thyrocervical trunk)
–> middle 1/3rd: Branches of descending thoracic aorta
–> lower 1/3rd: Branches from left gastric artery, inferior phrenic artery
Venous drainage
–> Upper 1/3rd: inferior thyroid vein
–> Middle 1/3rd: Azygous vein
–> lower 1/3rd: oesophageal branches left gastric vein
Lymphatic drainage:
–> upper 1/3rd: deep cervical nodes
–> Middle 1/3rd: superior and posterior mediastinal nodes
–> lower 1/3rd: Left gastric nodes and coeliac plexus
Describe the musculature of the oesophagus
-Upper 1/3rd: striated
-MIddle 1/3rd: mixed
-Lower 1/3rd: smooth
What is the anatomical mechanism that normally prevents gastro-oesophageal reflux?
Lower oesophageal sphincter: functional sphincter which is a high pressure zone ~2-5cm
-Angle of his: oesophagus enters stomach at acute angle
-Phreno-oesophageal ligament which encircles gastro-oesophageal junction
-Prominent mucosal folds at gastro-oesophageal junction
-Increase in intra-abdominal pressure causes compression of abdominal part of oesophagus
What type of diaphragmatic hernias do you know of?
Congenital
-Bochdalek
-Morgagni
Aquired
Hiatus hernia
–> sliding
–> rolling
Risk factors for hiatus hernia
-Age related degeneration
Chronically raised intra-abdominal pressure
–> coughing
–> obesity
–> pregnancy
Why is a sliding hiatus hernia a risk factor for gastro-oesophageal reflux?
-Migration of LES into chest results in loss of high-pressure zone. This predisposes pt to GORD
What are the constrictions of the oesophagus?
Cricoid cartilage at C5/6 –> 15cm from incisors
Arch of aorta T4/5 –> 22.5cm from incisors
Left principal bronchus –> 27cm from incisors
Diaphragmatic hiatus T10/11 –> 40cm from incisors
ABCD:
-Arch of aorta
-left main bronchus
-Cricoid cartilage
-Diaphragm
What is the cell lining of oesophagus?
Stratified squamous
What is barrett’s oesophagus?
Columnar metaplasia with increased risk of developing adenocardinoma
What is achalasia?
-Oesophageal motility disorder involiving the smooth muscle layer of the oesophagus and LES. It is characterised by incomplete LES relaxation, increased LES tone and lack of peristalsis of the oesophagus
What is the microscopic picture of achalasia?
-Hypertrophied musculature with the abscence of a myenteric plexus
Course of oesophagus
-Originates at level of C6 (inferior border of cricoid cartilage)
-Runs in superior/posterior mediastinum
-Enters abdomen at diaphragmatic hiatus (T10)
-Abdominal part terminates by joining cardiac orifice of stomach at T11
What are the tributaries of the azygous vein?
Right handed PM Loves Eating Burgers
-Right superior intercostal vein
-Hemiazygous and accessory hemiazygous
-Pericardial veins
-Mediastinal veins
-Lower right posterior intercostal veins
-esophageal veins
-Bronchial veins
also13, 19
What structures pass through the hilum of the lung?
-Pulmonary artery and vein (most anteiror)
-Right and left main bronchus (most posterior)
-Bronchial artery and vein
-Lymph nodes
-Autonomic nerves
VAD anteiror to posterior: vein, artery, duct
Identify the surface anatomy of the lung on the skeleton?
Apex: curved line from the sternoclavicular joint to 3cm above the junction between the medial 1/3rd and the middle 1/3rd of the clavicle
Anterior border: sternoclavicular joint to the xiphisternal joint behind the lateral border of the sternum (left lung deviates laterally from the sternum ath the 4th costal cartilage to form the cardiac notch)
Inferior border: line drawn between 6th rib MCL, 8th rib MAL, 10th rib vertebral column
Posterior border: transverse process of C7-T10
Hilum: opposite T5, T6, T7
Carina: at the level of T4
