The testis are where spermatozoa are made, the spermatozoa also known as sperm require a slightly lower temperature than body temperature to survive and thrive, that is why the testis are dropped slightly to the outside of the body.
the above picture is a great picture showing the anatomical structures within the testis.
LEYDIG CELLS
Leydig cells are the primary source of testosterone or androgens in males. they are located in the interstitial space present outside the seminiferous tubules in the testes.
SEMINIFEROUS TUBULES
the seminiferous tubules are the location where spermatogenesis takes place, sperm are made within the seminiferous tubules.
EPIDIDYMIS
this is the structure above the seminiferous tubules, this is the structure where sperm are stored and become mature. the maturation process within the epididymis takes 6-12 days as they travel through th eepididymis and once matured they reach and are stored within the tail of the epididymis.
When ejaculation occurs, sperm is forcefully expelled from the tail of the epididymis into the deferent duct. Sperm then travels through the deferent duct through up the spermatic cord into the pelvic cavity, over the ureter to the prostate behind the bladder then into the urethra for expellation