Describe the structure, location and blood, lymph and nerve supply to the following: i. Scrotum ii. Penis iii. Prostate gland iv. Urethra v. Vas deferens vi. Seminal vesicles vii. Cowper's gland viii. Epididymis

18.viii. Epididymis

• Structure: The epididymis is a comma-shaped, highly convoluted tube, approximately 6 meters (20 feet) long when uncoiled. It consists of a head (caput), body (corpus), and tail (cauda). Its wall contains smooth muscle that aids in moving sperm.
• Location: It is located on the posterior aspect of each testis, extending from the superior pole to the inferior pole.
• Blood Supply: The epididymis receives arterial blood primarily from the testicular artery (a branch of the abdominal aorta) and also from the artery to the vas deferens (a branch of the inferior vesical artery). Venous drainage is via the pampiniform plexus, which eventually forms the testicular vein.
• Lymph Supply: Lymphatic drainage follows the testicular vessels and drains into the lumbar (para-aortic) lymph nodes.
• Nerve Supply: The epididymis is innervated by autonomic nerves from the testicular plexus, which contains both sympathetic and parasympathetic fibers. Sympathetic fibers originate from T10-L1 spinal segments, and parasympathetic fibers are from the vagus nerve.