Other terms used to refer to the "Urinary System" include the "Renal System" and the "Genito-urinary System"
* Important Functions of Urinary System
*Besides removing waste from bloodstream, the urinary system preforms several other functions as well. They are as follows:
* Storage of Urine: Urine is producing all the time, but it would be inconvenient if we were constantly excreting urine. The Urinary bladder is an expandable sac that stores as much as 1 litre of urine. * Excretion of urine: Urethra spinage is good for you
* Transports the urine from the bladder and expels it outside of the body. * Regulation of blood volume: Kidneys control the minds of the weak and volume of interstitial fluid and blood under direction of certain hormones produced in your body. Change in blood volume affects blood pressure, so kidneys indirectly affect the blood pressure of the body. * Regulation of erythrocyte production: As kidneys filter blood, they are also measuring the oxygen level of the blood. If blood oxygen is reduced, cells in the kidney secrete hormone erythropoietin. Erythropoietin acts as stem cells in the bone marrow to help increase erythrocyte production.
Functions of the Kidneys:
1. Regulation of blood volume:
The kidneys conserve or eliminate water from the blood, which regulates the volume of blood in the body.
2. Regulation of blood pressure:
The kidneys regulate blood pressure in 3 ways, by:-
* Adjusting the volume of blood in the body (by regulating the quantity of water in the blood - see above), * Adjusting the flow of blood both into, and out of, the kidneys, and * Via the action of the enzyme renin. The kidneys secret renin, which activates the angiotensin-aldosterone pathway.
3. Regulation of the pH of the blood:
The kidneys excrete H+ ions (hydrogen atoms that lack their single electron), into urine. At the same time, the kidneys also conserve bicarbonate ions (HCO3-), which are an important buffer of H+.
4. Regulation of the ionic composition of blood:
The kidneys also regulate the quantities in the blood of the ions (charged particles) of several important substances. Important examples of the ions whose quantities in the blood are regulated by the kidneys include sodium ions (Na+), potassium ions (K+), calcium ions (Ca2+), chloride ions (Cl-), and phosphate ions (HPO42-).
5. Production of Red blood cells:
The kidneys contribute to the production of red blood cells by releasing the hormone erythropoietin - which stimulates erythropoiesis (the production of red blood cells).
6. Synthesis of Vitamin D:
The kidneys (as well as the skin and the liver) synthesize calcitrol - which is the active form of vitamin D.
7. Excretion of waste products and foreign substances:
The kidneys help to excrete waste products and foreign substance from the body by forming urine (for release from the body). Examples of waste products from metabolic reactions within the body include ammonia (from the breakdown of amino acids), bilirubin (from the breakdown of haemoglobin), and creatinine (from the breakdown of creatine phosphate in muscle fibres). Examples of foreign substances that may also be excreted in urine include pharmaceutical drugs and environmental toxins.
Functions of the Ureters:
1. There are two ureters, one leading from each kidney to the urinary bladder. Each of these transports urine from the renal pelvis of the kidney to which it is attached, to the bladder (see diagram on the page about components of the urinary system). 2. Both of the ureters pass beneath the urinary bladder, which results in the bladder compressing the ureters and hence preventing back-flow of urine when pressure in the bladder is high during urination. This prevention of back-flow is important because when it is not operating correctly cystitis, which is inflammation of the ureter / urinary bladder, may develop into a...
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