100+ Free FC Plast Surg(SA) Part I Practice Questions

Explanation: The frontal (temporal) branch of the facial nerve passes over the middle third of the zygomatic arch within or just deep to the temporoparietal fascia (superficial temporal fascia). Injury to this branch causes paralysis of the frontalis muscle, leading to eyebrow ptosis and loss of forehead wrinkle movement. Its trajectory along Pitanguy's line makes it vulnerable during temporal and facial dissections.

Explanation: The latissimus dorsi muscle is a Mathes and Nahai Type V muscle flap primarily supplied by the thoracodorsal artery, a continuation of the subscapular artery. The thoracodorsal pedicle enters the deep surface of the muscle approximately 8 to 10 cm distal to the axillary artery origin. Secondary segmental arterial supply comes from the posterior intercostal and lumbar perforators.

Explanation: The adductor pollicis muscle has transverse and oblique heads, both of which are innervated by the deep branch of the ulnar nerve (C8-T1). It functions to adduct the thumb toward the index finger metacarpal and is assessed clinically via Froment's sign when ulnar nerve weakness is present.

Explanation: Fibroblasts migrate into the wound environment around day 3 to 5 post-injury under the influence of growth factors such as TGF-beta and PDGF. They synthesize structural proteins, including glycosaminoglycans, fibronectin, and collagen (initially Type III, later replaced by Type I during maturation), providing tensile strength to the healing tissue.

Explanation: Plasmatic imbibition is the initial phase of skin graft survival lasting 24-48 hours, during which the graft passively absorbs nutrient-rich exudate and oxygen from the wound bed via capillary action. This process results in a weight gain of up to 40% before functional capillary connections (inosculation) are established.

Explanation: Mathes and Nahai Type II muscle flaps possess one or more dominant vascular pedicles along with secondary minor segmental pedicles. Examples include the gracilis (dominant medial circumflex femoral artery) and rectus femoris muscles. Transposition can usually be sustained on the dominant pedicle alone after dividing the minor pedicles.

Explanation: The superficial branch of the radial nerve passes under the tendon of the brachioradialis to become subcutaneous in the distal forearm. It supplies sensory innervation to the skin of the anatomical snuffbox, dorsum of the thumb, index finger, middle finger, and radial aspect of the ring finger proximal to the distal interphalangeal joints.

Explanation: Hypertrophic scars remain strictly confined to the original injury boundaries and frequently regress or soften over months to years. In contrast, keloids characteristically extend beyond the original margin of the wound, invade adjacent normal skin, contain large hyalinized collagen bundles, and show minimal tendency toward spontaneous regression.

Explanation: A standard Z-plasty constructed with 60-degree limb angles yields a theoretical length gain of 75% along the central limb axis and reorients the scar vector by 60 degrees. 30-degree angles provide 25% gain, while 45-degree angles yield a 50% gain in length.

Explanation: Bupivacaine is an amide local anesthetic with high lipid solubility and approximately 95% plasma protein binding (chiefly to alpha-1-acid glycoprotein), resulting in a long duration of nerve block (4 to 8 hours). Lidocaine has ~65% protein binding and a duration of 1 to 2 hours without epinephrine.