REPRODUCTION Human Reproductive Systems Human Reproduction and Development

REPRODUCTION Human Reproductive Systems

Human Reproduction and Development n Takes place internally n Depends on the endocrine system (hormones), nervous system, and reproductive system.

Human Reproduction and Development n Gonads are sex organs that produce gametes (egg and sperm). n That’s right, I said gonads!!

Human Reproduction and Development n Male gonads are the testes, which produce sperm and male sex hormones.

Human Reproduction and Development n Female gonads are the ovaries, which produce eggs (ova) and female sex hormones.

The Male Reproductive System n Testes are outside the body cavity n n Why? What could be the benefit that out weighs the potential harm?

The Male Reproductive System n n Sperm is produced at approximately 93°F Body Temperature is approximately 98. 6°F

Inside the testes 1. Seminiferous tubules: sperm produced by meiosis. n Spermatocytes: cells that divide by meiosis to produce spermatids n Spermatids mature into sperm

Seminiferous Tubules - extend over 1700 ft

Spermatogenesis n n n Begins at puberty Approx. 200, 000 sperm produced each day! Sperm stored in the Epididymis to mature.

Gametogenesis

Sperm Production in Testis

Testis

Sexual Structures n n n Vas Deferens – carries sperm from epididymis to urethra Urethra – carries sperm to outside the body Seminal vesicles - add fructose and nutrients to sperm as they pass. Prostate gland - secretes a milky alkaline fluid. Sperm and secretions make up semen.

Male Sex Hormones n Follicle-stimulating Hormone (FSH) n n Luteinizing Hormone (LH) n n Promotes sperm maturation Stimulates cells to secrete testosterone Testosterone n n Sperm formation Secondary sex characteristics