The type of gland that secretes its products into ducts that open onto surfaces, such as a gland in the lining of the digestive tract, is called ______ gland.

The type of gland that secretes its products into ducts that open onto surfaces, such as a gland in the lining of the digestive tract, is called an exocrine gland.

Exocrine glands are different from endocrine glands, which release their products directly into the bloodstream. The main characteristic of exocrine glands is their use of ducts to transport secretions to specific sites. Examples of exocrine glands include sweat glands, salivary glands, and glands within the digestive system that secrete enzymes and fluids to aid in digestion. The secretion process in exocrine glands is often essential for many bodily functions, such as digestion, temperature regulation, and lubrication of surfaces. Thus, understanding the role of exocrine glands is crucial in fields like biology, medicine, and physiology.