How are exocrine glands different from endocrine glands?

• A. Exocrine glands are always unicellular, whereas endocrine glands are always multicellular.
• B. Exocrine glands are found only in the digestive system, whereas endocrine glands are found only in the nervous system.
• C. Exocrine glands secrete their products through ducts onto an epithelial surface or into a body cavity, whereas endocrine glands secrete hormones into interstitial fluid and then the bloodstream.
• D. Exocrine glands secrete hormones directly into the bloodstream, whereas endocrine glands release their products through ducts onto body surfaces.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the basic definitions of exocrine and endocrine glands. Exocrine glands release their secretions onto epithelial surfaces or into body cavities, while endocrine glands release hormones directly into the bloodstream.
2. Step 2: Identify the mode of secretion for each gland type. Exocrine glands use ducts to transport their secretions, whereas endocrine glands are ductless and secrete hormones into the interstitial fluid surrounding the cells.
3. Step 3: Recognize the types of secretions. Exocrine glands typically secrete enzymes, mucus, or other substances, while endocrine glands secrete hormones that regulate various physiological processes.
4. Step 4: Note the locations and functions. Exocrine glands can be found in various systems (e.g., digestive, respiratory), and endocrine glands are part of the endocrine system, influencing distant target organs via the bloodstream.
5. Step 5: Summarize the key difference: Exocrine glands secrete products through ducts onto surfaces or cavities, whereas endocrine glands secrete hormones into interstitial fluid and then the bloodstream for systemic distribution.