Hormones are produced in the pituitary, the thyroid, the parathyroids, the adrenals, the thymus, the pineal, the islands of Langerhans and the gonads or sex glands. However many other organs and parts of the body also produce hormones. Thus the hypothalamus, a part of the brain, releases several hormones that trigger the release of hormones in the pituitary and other ductless glands, and also influences a wide variety of metabolic processes. The small intestines, the kidneys and especially the placenta of pregnant women likewise release hormones.
For the various organs of the body to function harmoniously they must be in touch with one another. A main means for transmitting messages from one organ to another is the nervous system. The other is the hormonal system. The nerves might be said to work like a telephone. It requires a hookup at each end and a line along which the message or impulse travels, and this is also true of nerves. Thus in the skin there are tiny receptors that pick up such sensations as heat, cold and pain and carry them to the brain.
For the various organs of the body to function harmoniously they must be in touch with one another. A main means for transmitting messages from one organ to another is the nervous system. The other is the hormonal system. The nerves might be said to work like a telephone. It requires a hookup at each end and a line along which the message or impulse travels, and this is also true of nerves. Thus in the skin there are tiny receptors that pick up such sensations as heat, cold and pain and carry them to the brain.