What are the Different Functions of Kidneys?
The excretory system refers to the human body system that is responsible for the excretion task which means physical procedure of releasing wastes. Our Kidneys are part of this excretory system and have several tasks to perform. This post is an extension to the previous post (why kidney is an important organ?)
3. Different Hormone Production
Healthy kidneys make significant substances in the body called ‘hormones’. A hormone is a chemical produced by the body which is released into the blood. These hormones travel in the bloodstream like ‘messengers’ and help different organs by giving signals to regulate blood pressure, red blood cell production and the calcium balance in the body. Kidneys produce many different hormones and regulate various body functions.
a) Regulates blood pressure
When the blood runs through arteries in the body which is called circulatory system, it generates the force on the arterial walls. This process is known as blood pressure which relies on the heartbeat rate and pressure of the blood.
It is important to have blood pressure within normal range. This means blood pressure should neither be higher or less than the required healthy parameters. Regulating normal blood pressure is one of the prime jobs done by kidneys.
In a normal healthy condition, kidneys produce a hormone called renin. This hormone is generated by the kidneys to control blood pressure. Whenever a person’s blood pressure goes low, kidney releases renin hormone to alert the body blood vessels squeeze and become smaller and firm resulting in less blood flow with adequate pressure to reach everywhere in the body. Similarly high pressure is controlled by blood vessels expansion to give more space and slow down of blood flow speed.
b) Regulates red blood cells in the body
Our body requires sufficient oxygen level to survive. Red blood cells (RBCs) are the carrier of oxygen in the body. Red blood cells transports oxygen from the lungs to supply it throughout the body. Red blood cells provide us the energy required for our day to-day’s activities. Inadequate oxygen supply in the body is a condition known as hypoxia in medical terms.
Kidneys balancing act plays a vital role as production of any hormone should be within significant range to maintain good health. Overproduction of RBC can result in hemochromatosis disease in which too much iron is generated in the body which can further damage many body organs like heart, liver and pancreas; endocrine glands and joints etc.
Erythropoietin (EPO) is a hormone produced by peritubular capillary lining cells of the kidney. These kidney cells are able to sense oxygen levels in the body. When kidney receive less oxygen due to anaemia, peritubular capillary lining cells release erythropoietin hormone which sends the message immediately to the body mechanism (bone marrow) to increase the production red blood cells.
4. Managing pH Levels in the Body
Potential Hydrogen balance, commonly known as the pH balance, is the measurement of acidity and alkalinity. We know our body has high percentage of water and pH is a measure of how acidic a water-based solution is. Therefore pH level is used to know how much acid is mixed up in the fluids in a person’s body. The kidneys prevent blood plasma from becoming too acidic or basic by regulating ions.
Both acid and alkaline are checked on the pH scale ranging from 0 (completely acidic) to 14 (completely alkaline). A pH of 7.0 is considered neutral. Normally the body maintains the pH of blood close to 7.40. If this balance changes, and fluid in the body gets on either extreme side on the scale, the condition can create many health problems.
Healthy kidneys regulate this pH balance by filtering the acids and bases in the blood regularly by removing extra acid or base in the form of urine.
5. Produce an Active Form of Vitamin D for Healthy Bones
Like other nutrients, vitamin D is equally essential. Vitamin D is necessary to utilise calcium we receive from dairy products and some other foods also. Calcium is needed to make strong bones and teeth.
We get required amount of vitamin D from food, sun’s ultraviolet rays and vitamin pills. Kidneys convert vitamin D from supplements or the sun to the active form of vitamin D that is required by the body.
Apart from food and supplement, this particular vitamin D is also produced by special skin cells when they are exposed to sunlight. If the skin cells are unable to absorb vitamin D, then the liver do the needful. Incase for any medical reason if the liver fails, the same task is done by the kidneys.