The nourishing cells in the seminiferous tubules are

The seminiferous tubules contain two types of cells on their inside: male germ cells (spermatogonia) and Sertoli cells.

Sertoli cells provide nutrition to the developing germ cells (spermatozoa). Because of their supporting and nourishing role, Sertoli cells are also known as sustentacular cells or nurse cells.

Leydig cells, also known as interstitial cells, are located in the interstitial spaces outside the seminiferous tubules and synthesize and secrete testicular hormones called androgens.

Follicular cells are found in the ovaries, not in the testes.

Answer: Sustentacular cells