gonad

The organ responsible for the production of reproductive cells (germ cells or gametes): in males the gonads (testes) produce spermatozoa, in females the gonads (ovaries) produce ova. In vertebrates the gonads also synthesize and secrete sex hormones (androgens, oestrogens, and progestagens): androgens are most abundant in males; oestrogens and progestagens in females.

The gonads are a combined gland providing both exocrine and endocrine functions.

In males, the male gonads, known as the testes or testicles, secrete the class of hormones called androgens, and produce spermatazoa. In females, the female gonads, known as the ovaries, secrete the hormones estrogen and progesterone, as well as ova.

The gonads are controlled hormonally by luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secreted by the anterior pituitary gland.

Gonads start developing as a common anlage, and only later are differentiated to male or female sex organs.

Although medically the term can refer to either male gonads (testicles) or female gonads (ovaries), the vernacular, or slang use of "gonads" (or "nads") usually only refers to the testicles.