Which organ is an example of an endocrine gland?

Which organ is an example of an endocrine gland?

• A. Pancreatic islets
• B. Salivary gland
• C. Sweat gland
• D. Pituitary gland

Answer: (D)

Endocrine glands secrete hormones directly into the bloodstream rather than onto surfaces or through ducts. The pituitary gland is a classic endocrine gland because it releases multiple hormones directly into the blood to regulate growth, metabolism, and other glands. In contrast, salivary and sweat glands are exocrine—they have ducts that carry their secretions to a surface. The pancreatic islets are endocrine, but the pancreas as a whole is primarily an exocrine organ with digestive enzymes produced in ducts, while the islets are just scattered endocrine tissue within it. So the pituitary gland best fits the description of an organ that is an endocrine gland.

Endocrine glands secrete hormones directly into the bloodstream rather than onto surfaces or through ducts. The pituitary gland is a classic endocrine gland because it releases multiple hormones directly into the blood to regulate growth, metabolism, and other glands. In contrast, salivary and sweat glands are exocrine—they have ducts that carry their secretions to a surface. The pancreatic islets are endocrine, but the pancreas as a whole is primarily an exocrine organ with digestive enzymes produced in ducts, while the islets are just scattered endocrine tissue within it. So the pituitary gland best fits the description of an organ that is an endocrine gland.