The cells that nourish the developing sperm are

Sertoli cells, also known as sustentacular cells, are located in the seminiferous tubules of the testes. They provide physical and nutritional support to developing sperm cells during spermatogenesis. Sertoli cells play a crucial role in the maturation and protection of sperm as they undergo the process of becoming fully functional spermatozoa.

Leydig cells (interstitial cells) produce and secrete testosterone that plays a vital role in the development and maintenance of male accessory sex organs, as well as the development of secondary sexual characteristics.

Paneth cells, primarily found in the small intestine, secrete lysozyme.

Schwann cells provide support and insulation to peripheral nerve fibers. They produce the myelin sheath, which is essential for faster transmission of nerve impulses along axons.