Physiology Purely serous salivary glands secrete which of the following substances? A Mucinogen and other glycoproteins B Enzymes and bicarbonate ions C Fibrous proteins and proteoglycans D Hormones and other regulatory agents 💡 Explanation Purely serous salivary glands secrete which of the following substances? ✓ Correct Answer: B. Enzymes and bicarbonate ions