The relationship between the kidneys and homeostasis is a crucial one in that the kidneys maintain the volume of the blood, remove nitrogenous wastes and regulate pH. Homeostasis is the regulation of the processes in the body to maintain a constant internal temperature which is vital for living organisms to function. This requires the excretion of metabolic wastes, the maintenance of a water balance and the regulation of chemicals within the body.
The maintenance of a constant internal environment ensures that body organs are able to operate efficiently. Homeostasis is maintained when temperature, heart and respiratory rates, blood pressure, water balance, blood sugar levels and detoxification processes are all within permissible levels. The skin is one of the organs which helps to maintain temperature, the heart maintains the heart rate and the ribs and diaphragm regulate the respiration rate. The pancreas plays a role in the maintenance of blood sugar levels and the liver is vital for the detoxification of the body. The role of the kidneys and homeostasis maintenance is the regulation of blood pressure and water balance. Homeostatic functions such as the excretion of toxic metabolic by-products such as urea, ammonia and uric acid are performed by the kidneys.
There are three systems which are important in excretion. There is the respiratory system where lungs remove CO2 and water; the integumentary system comprising the skin where active sweat glands draw heat from the body and blood vessels in the skin allow heat to escape; and the urinary system where the kidneys remove urine from the body. A healthy kidney maintains homeostasis through the removal of harmful wastes from the body and controls the balance of substances in the blood such as water, acids, ions and salts. The kidneys and homeostasis are vital for internal health and function.
Not only does the kidney and homeostasis maintenance require the removal of waste but also the control of which substances are reabsorbed by the body after the waste products have been filtered out. Homeostasis requires a certain volume of extracellular fluid in which there is a certain balance of ions and pH. The anti-diuretic hormone released from the pituitary gland in the brain is released into the blood when levels of fluid in the blood are low. The hormone decreases the absorption of water in the kidneys and homeostasis is stabilized. The same hormone acts if there is too much fluid in the blood for homeostasis. Less hormone is released, more water is absorbed by the kidneys and larger quantities of urine are produced.