Male Anatomy

The male reproductive system consists of a number of sex organs that play a role in human reproduction. These organs are located both externally and internally, and are responsible for producing, storing, and delivering sperm, as well as synthesizing hormones such as testosterone.

Overview

• External genitalia:
  • Penis: Intromittent organ for sexual intercourse and urination.
  • Scrotum: Sac of skin that holds and protects the testes, regulates temperature.
• Internal genitalia:
  • Testes: Produce sperm and testosterone.
  • Epididymis: Site of sperm maturation and storage.
  • Vas deferens: Transports sperm from epididymis to ejaculatory duct.
  • Seminal vesicles: Secrete fluid that nourishes sperm.
  • Prostate: Produces prostatic fluid, helps regulate urine flow.
  • Bulbourethral glands: Secrete pre-ejaculate for lubrication.

Structure and Function

• Penis: Contains erectile tissue (corpora cavernosa and corpus spongiosum), urethra for semen and urine, glans, and foreskin.
• Scrotum: Contains the testes and epididymides, regulates temperature via cremaster muscle and dartos fascia.
• Testes: Contain seminiferous tubules (site of spermatogenesis) and interstitial (Leydig) cells (produce testosterone).
• Epididymis: Long, coiled tube where sperm mature and are concentrated.
• Vas deferens: Muscular tube transporting sperm during ejaculation.
• Accessory glands: Seminal vesicles, prostate, and bulbourethral glands contribute fluids to semen.

Development

• Sexual determination: Genetic sex is determined at fertilization (XX = female, XY = male). The presence of the Y chromosome and SRY gene leads to testis development.
• Embryology: Testes develop in the abdomen and descend into the scrotum before birth. Androgens (testosterone, DHT) drive the development of male genitalia.
• Puberty: Increased testosterone leads to secondary sexual characteristics (body hair, deepening voice, muscle mass, etc.).

Clinical Significance

• Chromosomal abnormalities: Klinefelter's syndrome (XXY), Turner syndrome (XO), androgen insensitivity, and others can affect development.
• Common disorders: Cryptorchidism (undescended testes), hypospadias, erectile dysfunction, prostate enlargement/cancer, infertility.

Related Topics

• Penis
• Scrotum
• Testes
• Epididymis
• Vas deferens
• Seminal vesicle
• Prostate
• Bulbourethral gland
• [Sperm](../male 1/sperm.md)
• Seminiferous tubules
• Development
• Clinical significance

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For more details, see the linked articles above. This page serves as an overview and cross-reference for all aspects of male anatomy and reproductive health.