Abdominal Aorta - Lecture Notes Review

Flashcards covering anatomy, physiology, sonographic appearance, and laboratory values related to the abdominal aorta.

What are the two main sections of the aorta?

The Thoracic Aorta and the Abdominal Aorta, separated by the diaphragm.

Where does the Abdominal Aorta enter the diaphragm, becoming the abdominal portion?

The Abdominal Aorta enters/continues as it passes through the diaphragm into the abdominal cavity.

How many main segments are described for the Abdominal Aorta and what is the final landmark?

Proximal, middle, and distal segments ending at the iliac bifurcation.

What is the final bifurcation of the Abdominal Aorta?

Iliac bifurcation into the right and left common iliac arteries at the level of the umbilicus.

List the main branches of the Abdominal Aorta from superior to inferior.

Celiac trunk, Superior Mesenteric Artery, Renal Arteries, Inferior Mesenteric Artery, Iliac Bifurcation.

What are the three branches of the celiac trunk?

Common Hepatic Artery, Left Gastric Artery, Splenic Artery.

What does the Superior Mesenteric Artery supply?

The duodenum and other parts of the bowel, including the head of the pancreas.

What do the Renal Arteries supply?

The kidneys.

Which renal artery has a longer course and what is its relation to the IVC?

The right renal artery is longer and courses posterior to the IVC.

Where does the Inferior Mesenteric Artery originate and what does it supply?

Branches off the aorta anteriorly; supplies the colon.

Where is the Iliac bifurcation located?

At the level of the Umbilicus, forming the right and left common iliac arteries.

Which structures are posterior to the Abdominal Aorta?

Left lobe of liver, pylorus of stomach, body of pancreas, splenic artery and vein, left renal vein.

Which structures are anterior to the Abdominal Aorta?

Spine and psoas muscles.

What are the arterial wall layers of the Abdominal Aorta?

Tunica Intima, Tunica Media, Tunica Adventitia.

What is the Windkessel effect and its function?

A mechanism that maintains a consistent blood pressure by allowing blood flow during both systole and diastole.

How does the Abdominal Aorta contribute to bleeding control?

It contains nerve and chemical receptors that can trigger vasoconstriction or vasodilation in response to stimuli.

What is the sonographic appearance of the Abdominal Aorta lumen and walls?

Anechoic lumen with thick, straight walls.

What is the 'seagull sign' in relation to the celiac axis?

The celiac axis is the first major branch with the hepatic artery to the right and the splenic artery to the left.

Describe the Superior Mesenteric Artery’s appearance and relation to surrounding structures.

SMA runs inferior to the celiac axis, parallel to the aorta; it is small, round, anechoic and surrounded by echogenic fat; posterior to the splenic vein and pancreatic body and anterior to the aorta.

Where is the SMA in relation to the Splenic Vein, Pancreatic Body, and Aorta?

Posterior to the Splenic Vein and Pancreatic Body; anterior to the Aorta.

How is the Renal Artery visualized on ultrasound?

Medial to the renal hilum; seen in both coronal and transverse planes; in transverse it appears as an anechoic vessel extending laterally from the Aorta.

How is the Iliac Bifurcation seen on ultrasound?

In coronal and transverse views; in transverse, seen as two anechoic circles just distal from the Aorta.

What are the typical measurements of the Abdominal Aorta (length and diameters)?

Length ~14 cm; Proximal diameter ~2 cm; Distal diameter ~1.5 cm; should not exceed 3 cm at any level.

What laboratory values are mentioned and their clinical significance?

Hematocrit (percentage of RBCs; used to assess bleeding; decrease may indicate internal hemorrhage) and Cholesterol (abnormal levels may indicate pathology).