National League for Nursing (NLN PAX) Practice Exam

What do ductless glands in the human body secrete?

1. Enzymes

2. Mucus

3. Hormones

4. Metabolic wastes

The correct answer is: Hormones

Ductless glands, also known as endocrine glands, play a crucial role in the human body by secreting hormones directly into the bloodstream. Hormones are biochemical messengers that regulate various physiological processes, including growth, metabolism, and mood. Unlike exocrine glands, which have ducts to transport their secretions (like enzymes and mucus), ductless glands release their products directly into the circulatory system, allowing hormones to be distributed throughout the body to their target organs effectively. For example, the pancreas functions as both an endocrine and exocrine gland; its endocrine function involves the secretion of insulin and glucagon, hormones that regulate blood sugar levels. The thyroid gland is another example, secreting hormones that regulate metabolism, heart rate, and other vital functions. In contrast, enzymes are typically secreted by exocrine glands and act locally in the digestive system. Mucus is also secreted by exocrine glands, primarily for lubrication and protection of tissues. Lastly, metabolic wastes are byproducts of cellular metabolism that the body must eliminate, typically through excretory organs, not through secretion by ductless glands. Thus, the primary function of ductless glands is distinctly linked to the secretion of hormones, making the correct answer appropriate.