Source / episode info

• **Episode:**91
• **Title:**Divine Intervention Episode 91 – USMLE Anatomy Series 3 (Vascular Anatomy)
• **Published:**2019-04-05
• Source:Episode page

One-liner

This high-yield lecture details the complex arterial anatomy of the brain (Circle of Willis), the thoracic/abdominal aorta branches, critical anastomoses in the GI tract (foregut, midgut, hindgut), and key vascular relationships in the upper extremity.

High-yield summary

• Circle of Willis: The anterior communicating artery is the most common site for aneurysm formation; a basilar artery infarct can cause total pontine involvement, mimicking a locked-in syndrome.
• Aortic Dissection: Stanford A involves the ascending aorta and requires immediate surgical intervention; retrograde dissection often tracks down the right coronary artery (RCA).
• GI Anastomoses: The gastroepiploic anastomosis occurs along the greater curvature of the stomach (Right: from GDA/Common Hepatic Left: from Splenic Artery); the pancreaticoduodenal anastomosis connects superior and inferior branches.
• Aortic Branches & Changes: The celiac trunk supplies the foregut; the Superior Mesenteric Artery (SMA) supplies the midgut (up to splenic flexure); the Inferior Mesenteric Artery (IMA) supplies the hindgut.
• Upper Extremity Veins: For PICC line placement, the basilic vein is preferred over the cephalic or brachial veins due to anatomical safety and direct route to the subclavian/SVC system.
• External vs. Internal Iliac Anastomoses: The inferior epigastric artery (from external iliac) anastomoses with the superior epigastric artery (from thoracic aorta).

Learning objectives

• Identify the major arterial branches originating from the aortic arch, descending aorta, and celiac trunk.
• Describe the clinical presentation associated with infarcts in key brainstem arteries (e.g., PICA, AICA, Basilar).
• Trace the anastomotic pathways of the GI tract, specifically focusing on lesser/greater curvature connections.
• Differentiate between Stanford Type A and Type B aortic dissections regarding management and anatomical involvement.
• Recognize high-yield vascular relationships in the upper extremity (e.g., subclavian to axillary to brachial changes; basilic vein preference).