Male Reproductive System Overview

Gamete Definitions

• Gamete: A reproductive cell carrying genetic information. Humans have sperm (male) and ova (female) gametes.
• Ova: The female gamete, larger than sperm, containing genetic material and nutrients for embryo development.
• Spermatozoa (Sperm): The male gamete carrying genetic material.
• Zygote: The first cell formed from fertilization of an ovum by a sperm, containing a complete set of chromosomes from both parents.

Male Reproductive Organs: Gonads and Accessory Organs

• Gonads: The testes are the male gonads.
• Testes: Located in the scrotum, responsible for spermatogenesis (sperm production) and testosterone production.
• Accessory Organs: Seminal vesicles, prostate gland, bulbourethral glands, epididymis, vas deferens.

Testes Anatomy and Function

• Scrotum: A pouch of skin and muscle outside the body, maintaining the optimal temperature for sperm production.
• Tunica Albuginea: A fibrous capsule surrounding each testis, providing structural support and compartmentalizing seminiferous tubules.
• Seminiferous Tubules: Coiled structures within the testes lined with germinal epithelium; site of sperm production (spermatogenesis).
• Interstitial Cells (Leydig Cells): Located between seminiferous tubules, producing testosterone.
• Testosterone: A steroid hormone produced by interstitial cells; develops male reproductive tissues and secondary sexual characteristics.
• Epididymis: A highly coiled tube on the posterior surface of each testis; site of sperm maturation and storage, ensuring motility.

Sperm Transport Ducts

• Ductus (Vas) Deferens: A muscular tube transporting sperm from the epididymis to the ejaculatory duct.
• Ejaculatory Duct: Formed by the union of vas deferens and seminal vesicle duct; carries sperm and seminal fluid to the urethra.
• Urethra: The final duct, expelling semen containing sperm from the body.

Male Reproductive Glands

• Semen: A mixture of sperm and fluids from reproductive glands, transporting and nourishing sperm during ejaculation.
• Seminal Vesicles: Glands behind the bladder producing a viscous fluid rich in fructose and prostaglandins.
• Prostate Gland: A walnut-sized gland below the bladder secreting an alkaline fluid neutralizing vaginal acidity, enhancing sperm survival and motility.
• Bulbourethral Glands: Small glands at the base of the penis producing a lubricating pre-ejaculatory fluid.

Male External Genitalia

• Scrotum: A pouch of skin containing the testes, regulating temperature for optimal sperm production.
• Penis: The external organ for sexual intercourse and urination.
• Corpus Spongiosum: A cylindrical mass of erectile tissue along the underside of the penis, surrounding the urethra.
• Corpora Cavernosa: Two cylindrical masses of erectile tissue on the dorsal side of the penis, filling with blood during sexual arousal, causing an erection.
• Glans: The sensitive tip of the penis with nerve endings for sensitivity and pleasure.
• Prepuce (Foreskin): A skin covering the glans in uncircumcised males; protecting the glans and providing sensitivity.