Which statement about endocrine glands is true?

• A. They lack ducts and release products into surrounding connective tissue to reach the blood.
• B. They contain ducts that empty their products onto a surface.
• C. They secrete enzymes into the digestive tract.
• D. They are exclusively pancreatic.

Answer: (A)

Endocrine glands are ductless; their secretory cells release hormones directly into the surrounding interstitial space, and these hormones then diffuse into nearby capillaries to enter the bloodstream. This setup lets hormones travel to distant target tissues. Exocrine glands, by contrast, have ducts that carry secretions to surfaces or lumens, and the pancreas contains both endocrine (hormone-secreting islets) and exocrine components, so it is not exclusively endocrine.