Final answer:
The false statement about the endocrine glands is that sweat and sebaceous glands are examples of endocrine glands; they are in fact exocrine glands that secrete through ducts to nearby surfaces.
Step-by-step explanation:
To choose the false statement about the endocrine glands, let's evaluate each option given:
- They secrete chemical mediators called hormones. - True, endocrine glands release hormones into the interstitial fluid, which then diffuse into the bloodstream and reach target cells.
- Their secretions enter extracellular spaces and then pass into blood. - True, hormones are secreted into the surrounding interstitial fluid before diffusing into the blood.
- Sweat and sebaceous glands are examples of endocrine glands. - False, sweat and sebaceous glands are exocrine glands because they secrete substances via ducts to nearby surfaces, not directly into the bloodstream.
- Endocrine glands are ductless. - True, by definition, the endocrine glands are ductless and release their hormones directly into the blood.
- The pancreas, pituitary, thyroid, and hypothalamus are all endocrine glands. - True, although the pancreas also has exocrine functions, these organs are considered part of the endocrine system.
Therefore, the false statement is that sweat and sebaceous glands are examples of endocrine glands. They are actually exocrine glands.