Mention the location and structure of testes and explain about seminiferous tubules.

(N/A) Location and Structure of Testes:
The testes are situated outside the abdominal cavity within a pouch called the scrotum. The scrotum helps in maintaining the low temperature of the testes ($2-2.5^{\circ}C$ lower than the normal internal body temperature),which is necessary for spermatogenesis.
In adults,each testis is oval in shape,with a length of about $4$ to $5 \text{ cm}$ and a width of about $2$ to $3 \text{ cm}$. Each testis is covered by a dense covering.
Seminiferous Tubules:
Each testis has about $250$ compartments called testicular lobules. Each lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.
Each seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Sertoli cells.
The male germ cells undergo meiotic divisions finally leading to sperm formation,while Sertoli cells provide nutrition to the germ cells.
The regions outside the seminiferous tubules called interstitial spaces contain small blood vessels and interstitial cells or Leydig cells. Leydig cells synthesize and secrete testicular hormones called androgens.