In glandular epithelial tissue, what is the key difference between exocrine and endocrine glands?

• A. Exocrine glands are always unicellular, whereas endocrine glands are always multicellular.
• B. Exocrine glands are ductless and release hormones directly into the blood, whereas endocrine glands secrete through ducts onto body surfaces.
• C. Exocrine glands secrete their products through ducts onto an epithelial surface, whereas endocrine glands secrete hormones into interstitial fluid and then the bloodstream.
• D. Exocrine glands secrete only mucus, whereas endocrine glands secrete only enzymes.

Answer: (C)

Verified step by step guidance

1. Understand the basic function of glandular epithelial tissue: glands produce and secrete substances necessary for body functions.
2. Identify the two main types of glands: exocrine and endocrine glands, and recognize that their primary difference lies in how and where they release their secretions.
3. Recall that exocrine glands secrete their products through ducts that lead to an epithelial surface, such as the skin or the lining of the digestive tract.
4. Recognize that endocrine glands are ductless and release hormones directly into the interstitial fluid, from where these hormones enter the bloodstream to reach target organs.
5. Conclude that the key difference is the presence or absence of ducts and the destination of their secretions: exocrine glands use ducts to secrete onto surfaces, while endocrine glands secrete hormones into the blood.