Endocrine glands are defined as glands that secrete chemicals called hormones directly into the bloodstream.

Endocrine glands are defined as glands that secrete chemicals called hormones directly into the bloodstream.

• A. Pituitary gland
• B. Endocrine glands
• C. Exocrine glands
• D. Nerve cells

Answer: (B)

Endocrine glands release hormones directly into the bloodstream, so those chemical messages can travel to distant organs. That defining feature—ductless secretion into the blood—matches the concept described in the statement, which is why this term is the best answer. In contrast, glands with ducts release their secretions onto body surfaces or into body cavities (exocrine glands), such as sweat onto the skin or digestive enzymes into the gut, so they don’t fit the description. Nerve cells aren’t glands at all, though they can influence glands indirectly through signaling. A specific organ like the pituitary is an example of an endocrine gland, but the description refers to the general category rather than one particular gland.

Endocrine glands release hormones directly into the bloodstream, so those chemical messages can travel to distant organs. That defining feature—ductless secretion into the blood—matches the concept described in the statement, which is why this term is the best answer.

In contrast, glands with ducts release their secretions onto body surfaces or into body cavities (exocrine glands), such as sweat onto the skin or digestive enzymes into the gut, so they don’t fit the description. Nerve cells aren’t glands at all, though they can influence glands indirectly through signaling. A specific organ like the pituitary is an example of an endocrine gland, but the description refers to the general category rather than one particular gland.