Adaptasi Fisiologis Selama Puasa (Physiological Adaptation During Fasting)

Abstract

Fasting is an activity that has been done by people for long time. It is believed that fasting is good for health. During fasting people restrict food and water intake. How fasting makes body healthy and how body maintains the balance of energy and fluid during fasting are very interesting to learn. The objective of this review essay is to describe how the body maintain the balance of energy and fluid during fasting. During fasting, body lacks of food or energy intake, that means there is a relative lower blood glucose level. In this condition, the body produces hormones that increase the blood glucose level, like glucagons and epinephrine, that stimulate glicogenolysisis, lipolysis and gluconeogenesis, which maintain the blood glucose in the normal level. The processes above supply the glucose needed by the cells for metabolism. The lipolysis can reduce fat volume of the body, that is why fasting can reduce body weight and prevent the body from obesity and metabolic disorder. During fasting, the body also lacks of water intake, that means the body is relatively dehydration. In this condition the body produces hormons that reduce the urine output to minimize the liquid output from the body. They are antidiuretic hormone (ADH) from posterior hipophysis and aldosteron from kidney, that increase the natrium and water reabsorption from the tubulus of the kidney. The urine product restriction is supported by the vasoconstriction of the arthery that supplies blood to the kidney (arthery renalis). During fasting, the body produces high concentration and minimal volume of urine, that possibly the body to maintain liquid balance of the body, while the excretion of the toxic substances by the kidney still going on well. During fasting, the body do the physiological adaptations to maintain the energy and liquid balance. The processes to maintain the energy balance are glicogenolysis, lypolisis and gluconeogenesis, that are supported by glucagons and epinephrine. The process to maintain the liquid balance is the restriction of urine output, that is supported by ADH, aldosteron and the vasoconstriction of arthery renalis. Keywords: physiological adaptation, fasting