Signaling Hormonal and nervous regulation
Signaling. Hormonal and nervous regulation Signaling is necessary to coordinate the behavior and interaction of organisms, as well as organs and cells within the body. Animals primarily use odors, that is, chemical signaling. Odorous substances - various molecules - are excreted in animals by skin glands, with exhaled air, with urine and other liquids, and in plants with leaves, bark, flowers. Odors are perceived in various animals by olfactory organs or diffusely scattered in the integument by chemoreceptor cells. There are, on the one hand, attractants - attracting substances, including pheromones - attracting a sexual partner, on the other - repellents - repellent substances. Attractants and repellents are very effective in the fight against harmful insects, snails, rodents and other animals. Their range can reach several kilometers. Fragrant herbs, oils have been used since ancient times. Many organisms use light to communicate. Glow possess some bacteria, fungi, protozoa, jellyfis...