Human Reproduction

Sexual Reproduction:

·         Organisms produce germ cells called gametes: ova in females and sperm in males.

·         Each contains half the genetic information of a normal cell.

·         Join during fertilisation to produce a cell with full complement of genetic information.

Structures in Males:

·        Scrotum:

-        Cremaster muscle moves testes up or down to maintain temperature 2-3 Celsius below body temperature

·        Testes:

-        Male gonads

·        Epididymis:

-        A highly convoluted duct behind the testis, along which sperm passes to the vas deferens.

·        Vas deferens:

-        Tubes connecting testes with the urethra.

·        Seminal vesicle:

-        Each of a pair of glands which open into the vas deferens near to its junction with the urethra and secrete many of the components of sperm.

·        Bulbo-urethral gland:

·        Prostate gland:

-       Produce secretions in which sperm swim.

-       Viscous and Alkaline

Testes:

·         Two testes 10-15g each in weight

·         Develop near kidneys

-        Descend via inguinal canals into scrotum

·         Compartments called lobules

-        Contain seminiferous tubules

-        Site of spermatogenesis

·         Between lobules are Leydig Cells

-        Site of male hormone production

-        Mostly testosterone

Spermatogenesis

·         Takes 65-75 days

·         Begins with stem cells called spermatogonia

-        Undergo mitosis

·         New cells differentiate into primary…