What are ductless glands that secrete hormones directly into the bloodstream called?

Ductless glands that secrete hormones directly into the bloodstream are known as endocrine glands. These glands release their products, which are hormones, directly into the circulatory system, allowing these signaling molecules to be transported throughout the body to target organs or tissues, where they exert their effects. This mechanism is crucial for regulating various physiological processes, including metabolism, growth, reproduction, and homeostasis.

In contrast, exocrine glands are characterized by having ducts, through which they secrete substances like enzymes, saliva, and sweat directly onto the epithelial surfaces or into cavities instead of into the bloodstream. Secretory glands is a more general term that does not specifically define ductless secretion and could include both endocrine and exocrine actions. Accessory glands typically refer to organs or structures that assist in a specific function or process but do not fit the definition of glands that secrete directly into the bloodstream.