Lachmans TEST REVIEW (PERSONAL Back/Thorax) Part 2 Flashcards
(25 cards)
What causes the symptoms in aortic coarctation?
Increased blood pressure in the prestenotic portion of the aorta and its branches, leading to an enlarged aortic arch and branches and left ventricular hypertrophy.
What arteries are involved in the scapular & cervical collateral anastomosis?
Branches from the subclavian
Transverse cervical, deep cervical, suprascapular, dorsal scapular)
Axillary (subscapular, circumflex scapular branch)
What forms the internal thoracic anastomosis pathway?
Internal thoracic artery (from subclavian) connects via anterior intercostal arteries with posterior intercostal branches from the aorta.
Which branches are involved in the musculophrenic & mediastinal anastomosis?
Musculophrenic and mediastinal branches (from internal thoracic) communicate with phrenic and mediastinal branches of the descending aorta.
How do the superior and inferior epigastric arteries contribute to collateral flow?
The superior epigastric artery (from internal thoracic) anastomoses with the inferior epigastric artery, bypassing the aorta.
What is the intercostal anastomosis pathway?
Anterior intercostal branches (from internal thoracic) connect with posterior intercostal arteries (from aorta), also includes the supreme intercostal artery.
What arteries are involved in the spinal anastomosis?
The anterior spinal artery (from vertebral artery) communicates with segmental spinal branches of the posterior intercostals from the descending aorta.
What causes rib notching in aortic coarctation?
Enlargement of the intercostal arteries causes pressure erosion/resorption of the inferior borders of the ribs.
Why might patients with aortic coarctation experience leg cramping during exercise?
The increased oxygen demand in the lower limbs may exceed the capacity of the collateral circulation, leading to muscle ischemia and cramping.
What happens when the azygos vein is obstructed and the SVC is blocked?
All blood normally draining into the SVC must be rerouted to the heart via the IVC through collateral venous pathways.
What is the thoracoepigastric vein’s role in SVC obstruction?
Connects the lateral thoracic vein (drains to axillary vein → SVC) with the superficial epigastric vein (drains into great saphenous → femoral vein → IVC), forming a collateral route.
What is the first major collateral pathway in SVC obstruction?
Thoracic wall veins anastomose and drain into the axillary and internal thoracic veins, as well as tributaries of the femoral vein.
What is the second collateral system for SVC obstruction?
Internal thoracic venous system (superior epigastric, musculophrenic, anterior intercostal, perforating cutaneous veins) connects to the inferior epigastric vein, which drains into the external iliac vein → IVC.
What is the third collateral channel in SVC obstruction?
The vertebral venous plexus – includes longitudinal veins and segmental intercostal vein anastomoses, both inside and outside the vertebral canal.
How does the azygos route contribute to collateral circulation despite SVC obstruction?
Reversal of flow (due to valveless veins) allows blood from thoracic segmental veins to reach the azygos vein, which connects to the IVC.
How is the azygos vein formed?
Fom the confluence of the right ascending lumbar vein and subcostal vein.
What veins help the azygos system collect blood from the left side?
The hemiazygos and accessory hemiazygos veins drain the left thoracic wall into the azygos vein.
Can these collateral venous pathways also compensate for IVC obstruction?
Yes, the same pathways can allow reversed flow from the IVC to the SVC if the IVC is obstructed.
How can lymphatic metastasis from the esophagus reach abdominal lymph nodes?
Through rich lymphatic anastomoses, allowing spread to lymph nodes around the celiac artery.
What lymph nodes commonly spread esophageal cancer to the pleura and lungs?
Tracheobronchial lymph nodes.
How does lymph return to the venous system?
Via the thoracic duct and the right lymphatic duct.
How does venous drainage of the esophageal wall facilitate metastasis?
Through the azygos and hemiazygos veins (→ SVC) and portal system tributaries (lower esophagus → left gastric vein).
How does esophageal blood reach the heart through the systemic system?
Esophageal veins → Azygos vein → SVC → Right atrium.
Describe the pathway of venous spread from the esophagus to the lungs.
Portal vein → Hepatic vein → IVC → Right atrium & ventricle → Pulmonary artery → Pulmonary circulation → Lung metastasis.
