Which of the following is NOT a major exocrine product?

• A. Digestive juices
• B. Mucus
• C. Sweat
• D. Urine

Answer: (D)

Exocrine secretions are products released by glands through ducts onto surfaces or into body cavities. Digestive juices are classic examples: salivary, gastric, and pancreatic secretions flow into the digestive tract to aid digestion. Mucus is another exocrine product, produced by mucous glands and goblet cells to lubricate and protect surfaces. Sweat is also exocrine, produced by sweat glands and released onto the skin to help regulate temperature and excrete salts. Urine, however, is not a secretion from an exocrine gland. It’s formed by the kidneys as a filtrate of blood, then excreted through the urinary tract. It isn’t released via a duct onto a surface or into a body cavity as a glandular secretion. Therefore, urine is not a major exocrine product.