By studying this chapter, you should be able to do the following:
Describe the concept of hormone–receptor interaction.
Identify the factors influencing the concentration of a hormone in the blood.
Describe the mechanisms by which hormones act on cells.
Describe the role of the hypothalamus in the control of hormone secretion from the anterior and posterior pituitary glands.
Identify the site of release, stimulus for release, and the predominant action of the following hormones: epinephrine, norepinephrine, glucagon, insulin, cortisol, aldosterone, thyroxine, growth hormone, estrogen, and testosterone.
Discuss the use of testosterone (and its synthetic analogs) and growth hormone on muscle growth and their potential side effects.
Contrast the role of plasma catecholamines with intracellular factors in the mobilization of muscle glycogen during exercise.
Discuss the four hormonal mechanisms by which blood glucose homeostasis is maintained.
Graphically describe the changes in the following hormones during graded and prolonged exercise: insulin, glucagon, cortisol, growth hormone, epinephrine, and norepinephrine.
Describe the effect of changing hormone and substrate levels in the blood on the mobilization of free fatty acids from adipose tissue.
Hormones: Regulation and Action
Hormonal Control of Substrate Mobilization during Exercise
Blood Glucose Homeostasis during Exercise
adrenocorticotrophic hormone (ACTH)
angiotensin I and II
antidiuretic hormone (ADH)
follicle-stimulating hormone (FSH)
growth hormone (GH)
inositol triphosphate (IP3)
insulin-like growth factors (IGFs)
luteinizing hormone (LH)
melanocyte-stimulating hormone (MSH)
posterior pituitary gland
protein kinase C
thyroid-stimulating hormone (TSH)
Exercise imposes a variety of biological stresses on the body. A vigorous bout of exercise provides numerous challenges including the homeostatic regulation of blood glucose, body temperature, blood pressure, and blood volume. These responses to exercise are the physiologic culmination of localized regulatory factors that impact the major organs in addition to individual tissues and cells within the body. In a healthy individual, the physiologic stresses imposed by exercise are regulated simultaneously through a systemic communication process involving hormones.
In general terms, hormones are chemical messengers produced in one tissue that signal changes in other organs and tissues throughout the body. Hormones are transported throughout the body via blood where they interact with cellular receptors. The study of hormones, and their effects on the body, is called endocrinology. The endocrine system represents the various body ...