Glands are organs in the body that produce and secrete hormones, enzymes, and other substances. The term GLAND can refer to a variety of different organs, including the ADRENAL gland, which produces hormones such as adrenaline; the PINEAL gland, which produces melatonin; the THYROID gland, which produces hormones that regulate metabolism; the ENDOCRINE gland, which produces hormones that regulate growth and development; the LIVER, which produces bile; the SALIVARY glands, which produce saliva; the PROSTATE gland, which produces seminal fluid; and the LYMPH glands, which produce lymphocytes.