Question

What does each accessory sex gland contribute to semen?

Answer 1

1. Seminal Vesicles: Produce about 60% of semen volume; secrete an alkaline fluid rich in fructose (energy source for sperm), prostaglandins (stimulate female genital tract contractions), citrate, hyaluronidase enzyme, and fibrinogens.
2. Prostate Gland: Contributes about 30% of semen; secretes a slightly acidic, thin fluid rich in citric acid, acid phosphatase, enzymes (including clotting enzymes and fibrinolysin), and substances that nourish sperm and increase their motility.
3. Bulbourethral (Cowper’s) Glands: Secrete clear, alkaline mucus before ejaculation to lubricate the urethra and neutralize acidic urine residue, protecting sperm.

These secretions together form the liquid part of semen, helping sperm viability and mobility.