Surgical Anatomy and Physiology Flashcards

Which nerve is at risk during dissection along the medial aspect of the axilla during axillary lymph node dissection?

Answer: Long thoracic nerve

The long thoracic nerve runs along the serratus anterior on the medial axillary wall and, if injured, causes a winged scapula.

The pylorus regulates gastric emptying via contraction of which muscle layer?

Answer: Outer circular smooth muscle forming the pyloric sphincter

The pyloric sphincter is formed by a thickened ring of circular smooth muscle that controls passage of chyme into the duodenum.

During a thyroidectomy, which structure must be identified to prevent hypocalcemia postoperatively?

Answer: Parathyroid glands

Inadvertent removal or devascularization of the parathyroid glands leads to postoperative hypocalcemia due to loss of PTH secretion.

The hepatoduodenal ligament (portal triad) contains all of the following EXCEPT:

Answer: Hepatic vein

The hepatic veins drain directly into the inferior vena cava and are not part of the portal triad within the hepatoduodenal ligament.

Which layer of the peritoneum directly covers the abdominal organs and is reflected to form mesenteries?

Answer: Visceral peritoneum

Visceral peritoneum directly invests the organs and is continuous with the mesenteries that suspend them from the posterior abdominal wall.

In the context of surgical hemostasis, which coagulation pathway is initiated when tissue factor is exposed at a wound site?

Answer: Extrinsic (tissue factor) pathway

Exposed tissue factor binds factor VIIa to initiate the extrinsic pathway, which rapidly activates the coagulation cascade at sites of vascular injury.

The saphenous nerve, a branch of the femoral nerve, accompanies which vessel and is at risk during saphenous vein harvest?

Answer: Greater saphenous vein

The saphenous nerve runs alongside the greater saphenous vein, particularly below the knee, and can be injured during vein harvest causing medial leg paresthesia.