**Question:** Cremaster muscle is supplied by-

A. External iliac artery
B. Internal iliac artery
C. Umbilical artery
D. Rectus sheath artery

**Core Concept:** Understanding the arterial supply of the cremaster muscle is essential for postgraduate medical students, especially for those preparing for exams like NEET PG, USMLE, AIIMS, and FMGE. The cremaster muscle is a paired, smooth muscle layer beneath the testis in males, which contracts to elevate the testis during changes in body temperature.

**Why the Correct Answer is Right:** The cremaster muscle is supplied by the external iliac artery (A), which branches off the common iliac artery, a terminal branch of the abdominal aorta. The external iliac artery supplies the cremaster muscle directly, ensuring adequate blood flow for its contraction and testicular protection.

**Why Each Wrong Option is Incorrect:**

B. Internal iliac artery (B): The internal iliac artery is a continuation of the common iliac artery and supplies the pelvic organs. It does not supply the cremaster muscle.

C. Umbilical artery (C): The umbilical artery is a terminal branch of the abdominal aorta and supplies the umbilicus during fetal life. It does not supply the cremaster muscle.

D. Rectus sheath artery (D): The rectus sheath artery is a branch of the epigastric artery, supplying the rectus sheath and abdominal wall muscles. It does not supply the cremaster muscle.

**Clinical Pearl:** A thorough understanding of the arterial supply of the cremaster muscle helps in recognizing clinical scenarios, like scrotal swelling that could be due to testicular torsion or other testicular pathologies. Knowledge of the arterial supply can aid in prompt diagnosis and management.

**Correct Answer:** External iliac artery (A) supplies the cremaster muscle, ensuring proper functioning and testicular protection.