This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Genital System, Subject name: Anatomy
Cremaster muscle is supplied by 
Select and explain. 
A. Genital branch of genitofemoral nerve, B. Ilioinguinal nerve, C. Iliohypogastric nerve, D. Femoral nerve
A: Genital branch of genitofemoral nerve
Answer: A: Genital branch of genitofemoral nerve 
Explanation: Ans. a (Genital branch of genito-femoral nerve). (Ref. BD Chaurasia, Human Anatomy Vol. II 3rd ed. 172)CREMASTER# Cremaster Muscle consist of muscle fasciculi embedded in the cremasteric facia.# Fasciculi form loop that are attached laterally to inguinal ligament & medially to pubic tubercle, pubic crest, the conjoint lendon.# It is fully developed only in male.# It is supplied by Genital branch of the genitofemoral nereve (LI).# Its action is to suspend testis & can elevate it.# It also closes superficial inguinal ring by 'ball valve' mechanism when intraabdominal pressure is raised.# In UMN lesions above segment LI, Cremaster reflex is lost.