Surgical Anatomy and Physiology Flashcards

The Triangle of Doom in laparoscopic inguinal hernia repair defines a danger zone containing which critical structure?

Answer: External iliac vessels

The Triangle of Doom is bounded by the vas deferens medially and the spermatic vessels laterally, overlying the external iliac artery and vein which must not be stapled.

During splenectomy, which ligament must be divided to mobilize the spleen medially and avoid injury to the tail of the pancreas?

Answer: Splenorenal (lienorenal) ligament

The splenorenal ligament contains the splenic vessels and the tail of the pancreas; careful division prevents pancreatic injury and postoperative fistula.

Which physiologic principle explains why a tourniquet applied to a limb causes metabolic acidosis upon release?

Answer: Ischemic tissue accumulates lactic acid which washes into circulation on deflation

Anaerobic metabolism in the ischemic limb produces lactic acid, which rapidly enters systemic circulation when the tourniquet is deflated, causing transient metabolic acidosis.

The recurrent laryngeal nerve is at greatest risk of injury at which location during thyroid surgery?

Answer: At the ligament of Berry where it passes close to the inferior thyroid artery

The RLN is most vulnerable at the ligament of Berry (posterior suspensory ligament) where it may loop or branch adjacent to the inferior thyroid artery branches.

Which anatomic structure separates the anterior and posterior triangles of the neck and serves as a key landmark during neck dissection?

Answer: Sternocleidomastoid muscle

The sternocleidomastoid muscle divides the neck into the anterior and posterior triangles and is a central landmark guiding the planes of modified radical neck dissection.

The Frank-Starling law of the heart states that cardiac output increases when:

Answer: Ventricular preload (end-diastolic volume) increases, stretching myofibrils

Increased end-diastolic volume stretches the sarcomeres toward an optimal length, increasing the force of contraction and stroke volume per the Frank-Starling mechanism.

During a posterolateral thoracotomy, the surgical first assistant retracts which muscle that originates from the lower six ribs and inserts on the iliac crest and thoracolumbar fascia?

Answer: Latissimus dorsi

The latissimus dorsi is the large, flat muscle typically divided or retracted during posterolateral thoracotomy to access the thoracic cavity.