Endocrine glands secrete hormones directly into the bloodstream.

Endocrine glands secrete hormones directly into the bloodstream.

• A. Interstitial fluid
• B. Ducts
• C. Bloodstream
• D. Lymph

Answer: (C)

Endocrine glands are ductless, releasing hormones straight into nearby blood vessels. Once in the bloodstream, these hormones ride the circulatory system to reach distant target cells that have specific receptors for them, triggering the appropriate response. Interstitial fluid is just the fluid around cells and isn’t the main transport route for hormones. Ducts are used by exocrine glands to carry secretions to surfaces or cavities, not for endocrine signaling. Lymph is part of the immune system’s transport network, not the primary path for hormone signaling. So the bloodstream is the correct route for endocrine signaling.

Endocrine glands are ductless, releasing hormones straight into nearby blood vessels. Once in the bloodstream, these hormones ride the circulatory system to reach distant target cells that have specific receptors for them, triggering the appropriate response. Interstitial fluid is just the fluid around cells and isn’t the main transport route for hormones. Ducts are used by exocrine glands to carry secretions to surfaces or cavities, not for endocrine signaling. Lymph is part of the immune system’s transport network, not the primary path for hormone signaling. So the bloodstream is the correct route for endocrine signaling.