What is the difference between endocrine and exocrine glands?

Endocrine glands secrete hormones directly into the bloodstream, while exocrine glands secrete substances through ducts.

Endocrine glands are ductless glands that secrete hormones directly into the bloodstream. These hormones travel through the bloodstream to target cells and organs, where they regulate various physiological processes such as growth, metabolism, and reproduction. Examples of endocrine glands include the pituitary gland, thyroid gland, and adrenal gland.

Exocrine glands, on the other hand, secrete substances through ducts that lead to the surface of the body or into body cavities. These substances include enzymes, mucus, sweat, and saliva, and they play important roles in digestion, lubrication, and protection. Examples of exocrine glands include the salivary glands, sweat glands, and pancreas.

Another key difference between endocrine and exocrine glands is their mode of secretion. Endocrine glands secrete hormones in response to specific stimuli, such as changes in blood glucose levels or stress. Exocrine glands, on the other hand, secrete their substances continuously or in response to mechanical or chemical stimulation.

In summary, endocrine glands secrete hormones directly into the bloodstream to regulate physiological processes, while exocrine glands secrete substances through ducts for digestion, lubrication, and protection.