So, this topic is about the endocrine system. And we'll just talk about some basic information. And in this lesson, I lay the ground work for understanding how chronic disturbance of homeostasis is connected to chronic fatigue. And how chronic fatigue is linked to overtraining. And as you progress through the next five lessons in this particular topic, you will gain an excellent understanding about how the endocrine system responds to a chronic disturbance in homeostasis. But there are eleven organ systems making up the human body. There is the integumentary, or the skin, the muscular, the skeletal, the nervous, endocrine, circulatory, lymphatic respiratory, digestive, urinary or the excretory system, and the reproductive system. And we've touched upon a few of these. They all interact in someway to maintain homeostasis. And consequently, they all impact the athlete's performance in some way. The endocrine system, though, is the master controller, which is one reason why it is important for coaches and athletes to understand how this organ system works. Adaptation and maladaptation to training is intimately connected to the hormones released by the endocrine system. The endocrine system is one of two important methods the brain uses to gather information from the state of the body's internal environment. And it sends instructions out to the various organ systems to make the necessary adjustments. The nervous system is the other way the brain communicates with the body's systems. The nervous system receives and sends instructions very, very rapidly. But the instructional messages are destroyed very quickly. The endocrine system is much slower. But the effects last for quite a long time, because the messages are destroyed very, very slowly. Both systems are structured to sense information, organize an appropriate response, and then deliver the instructional messages to the proper organs or tissues. So while the two systems work together to maintain homeostasis, they differ a little bit in their delivery mechanisms. The endocrine system uses hormones as the message carrier that are transported through a network of blood vessels to the appropriate organ systems. Nerves relay messages in the form of neurotransmitters that are released from the nerve endings in response to electrical stimulus. The signal moves from one nerve to the next until it reaches the desired organ system. Our focus in this lesson is on the endocrine system that uses hormones to communicate. Now the word hormone is from the Greek word meaning stimulate, or spur into action. The type of hormones released depends on the specific stress encountered by the athlete during training. Some are designed to cause the release of energy, some to build protein or store glycogen. And there are a lot of other actions, as well, that are all essential for survival. So, when you've completed this lecture, you will be able to explain how hormones work. You'll be able to describe the difference between anabolic and catabolic hormones. Explain how the hypothalamus, the pituitary gland and the endocrine glands interact with each other. And you'll be able to discuss how testosterone, growth hormone, insulin, cortisol and progesterone contribute to adaptation, homeostasis and performance. So, let's get started.
