CSFA Surgical Anatomy and Physiology 5 — Questions and Answers
Question 1: The Triangle of Doom in laparoscopic inguinal hernia repair defines a danger zone containing which critical structure?
- Femoral nerve and lateral femoral cutaneous nerve
- External iliac vessels (Correct answer)
- Inferior epigastric vessels
- Obturator nerve
Correct 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.
Question 2: During splenectomy, which ligament must be divided to mobilize the spleen medially and avoid injury to the tail of the pancreas?
- Gastrosplenic ligament
- Splenorenal (lienorenal) ligament (Correct answer)
- Phrenicocolic ligament
- Splenophrenic ligament
Correct 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.
Question 3: Which physiologic principle explains why a tourniquet applied to a limb causes metabolic acidosis upon release?
- Hyperventilation during ischemia releases CO2
- Ischemic tissue accumulates lactic acid which washes into circulation on deflation (Correct answer)
- Tourniquet increases systemic vascular resistance raising pH
- Reperfusion delivers oxygen causing alkalosis
Correct 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.
Question 4: The recurrent laryngeal nerve is at greatest risk of injury at which location during thyroid surgery?
- Posterior to the carotid sheath
- At the ligament of Berry where it passes close to the inferior thyroid artery (Correct answer)
- In the tracheoesophageal groove above the thyroid cartilage
- Lateral to the jugular vein
Correct 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.
Question 5: Which anatomic structure separates the anterior and posterior triangles of the neck and serves as a key landmark during neck dissection?
- Platysma muscle
- Sternocleidomastoid muscle (Correct answer)
- Anterior scalene muscle
- Omohyoid muscle
Correct 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.
Question 6: The Frank-Starling law of the heart states that cardiac output increases when:
- Heart rate decreases and afterload increases
- Ventricular preload (end-diastolic volume) increases, stretching myofibrils (Correct answer)
- Contractility decreases due to sympathetic withdrawal
- Venous return decreases secondary to vasodilation
Correct 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.
Question 7: 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?
- Serratus anterior
- Rhomboid major
- Latissimus dorsi (Correct answer)
- External intercostal
Correct answer: Latissimus dorsi
The latissimus dorsi is the large, flat muscle typically divided or retracted during posterolateral thoracotomy to access the thoracic cavity.
CSFA Surgical Anatomy and Physiology 5
The Triangle of Doom in laparoscopic inguinal hernia repair defines a danger zone containing which critical structure?