The prostate is a gland that is part of the male reproductive system and is located inside the body. Its primary function is to produce a fluid that, together with sperm cells from the testicles and fluids from other glands, makes up semen. The muscles of the prostate also ensure that the semen is forcefully pressed into the urethra and then expelled outwards during ejaculation. The prostate gland is surrounded by a capsule of connective tissue containing many smooth muscle fibers and elastic connective tissue, which is why it feels very elastic to the touch when it is examined. The ducts in the prostate gland flow into the urethra, which passes through the prostate. The prostate also plays a role in hormone production and helps regulate urine flow. A normal functioning prostate is not critical for a person to live, but it is important for fertility.