Question

How do endocrine glands act as chemical messengers?

Answer 1

Endocrine glands secrete hormones which are chemical messengers. Chemical messengers are those substances which are produced by some cells but affects the function of other cells. Glandular hormones (such as thyroxine), neurotransmitters (such as acetylcholine), neurohormones (such as thyrotropic releasing hormone secreted by hypothalamus), local hormones (such as histamine) and pheromones (such as bombykol secreted by female silk moths to attract the males) are five types of chemical messengers. Glandular hormones are secreted by endocrine glands.