What controls the mixture of fuel used by the muscles What stimulates the adipose tissue to release more FFA How is the liver made aware of the need to replace the glucose that is being removed from the blood by exercising muscles If glucose is not replace , a hypoglycemic (low blood glucose) condition will occur. Hypoglycemia is a topic of crucial importance in discussing exercise as a challenge to homeostasis. Blood glucose is the primary fuel for the central nervous system (CNS) , and without optimal CNS function during exercise, the chance of fatigue and the risk of serious injury increase. Although blood glucose was used as an example, it should be notes that sodium, calcium, potassium, and pH, are also maintained within narrow limits during exercise. It should be no surprise them that there are a variety of automatic control s maintaining these variables within these limits.
11. Chapter 2 presented an overview of automatic control systems that maintain homeostasis. In that context, you also were introduced to cell signaling the fact that a wide variety of signals, some acting locally and others reaching all tissues, are needs for our adaption to a single bout of exercise, or to changes single bouts of exercise, or to repeated bours of exercise (training) that lead to changes in muscle structure and function. Although this chapter focuses primarily on one category of cell signaling, endocrine signals-the other types of signals (i.r., autocrine, paracrine, and synaptic) are crucial-not only for muscular adaptations, but also for the health-related benefits , such as reduced risks of type 2 diabetes and coronary heart disease. This chapter provides additional information on cell signaling, with an emphasis on neuroendocrinology, a branch of physiology dedicated to the systematic study of control systems. The first part of the chapter presents a brief introduction to each hormone, indicates the factors controlling its searetion,