Sensory deprivation and homeostasis.
Most afferent inputs are sensory stimulants, and physical activity is probably one of the most significant of all sensory stimulations. Gravity is a constant stimulus. These demands are also known as stress, and the stressor effect as the general adaptation syndrome (Selye). In this study, these demands are called sensory afferent stimuli, which are necessary triggers to start the hypothalamus-pituitary-adrenal mechanism and thus maintain the general mechanical, autonomic and metabolic functions of the body in the state of homeostasis. If the sensory stimulus is removed, there is no stressor effect and the cycle of response is eliminated. This results in a decreased hypothalamus-pituitary response and a decreased production of ACTH and corticoids. A decrease in the sensory input creates changes in the central nervous system and in the musculoskeletal system which are compatible with lack of the hypothalamus-pituitary responses. When a person becomes ill, physical inactivity as well as sensory and perceptual deprivation are at a maximum, and the absence of these stimuli interrupts the cycle of homeostasis. Physical activity is one of the most important stressors (sensory input) or triggering mechanisms for the cycle of homeostasis (hypothalamus-pituitary-adrenal cycle). Therefore, it is imperative to provide the patient with physical activities which ensure motion and take into account the effect of gravity. This is best accomplished by a program of physical, occupational and recreational therapy.
D000368:Aged; D005790:General Adaptation Syndrome / Q000503:physiopathology*; D006706:Homeostasis; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D005082:Physical Exertion; D010913:Pituitary-Adrenal System / Q000502:physiology; D012683:Sensory Deprivation; D013312:Stress, Physiological / Q000503:physiopathology*