The Renal & Urinary Systems
The urinary system is the body system that produces, stores and rids the body of waste water (urine) and regulates the composition of your blood and your bodies water levels. The main organs of the urinary system are two kidneys (forming the renal system) and a bladder as well as two ureters, the tubes that carry the urine to the bladder, and one urethra, the tube that carries the waste water out of the body.
The Kidneys
In the kidneys there are around one million nephrons, which are the filtering organs and these contain their own glomerulus, a network of capillaries, to filter the blood and remove it of its impurities. After the blood has been filtered and important nutrients reabsorbed the waste material is washed away in the urine.
The less water we consume the more concentrated our urine is. This is because the kidneys retain the level of water in the blood and as a result less water is released to flush away waste products. This is most evident in the morning, when you have generally not been drinking throughout the night your urine is more concentrated as your kidneys conserve water for the blood.
The Bladder
The body generally produces around 1.5 litres of urine a day. This is stored (not all at once!) in the bladder until it is released. The bladder is a muscular organ which behaves in the same way as a water balloon by expanding and shrinking depending on the level of urine. It can hold roughly half a litre of urine for anything between 2 and 5 hours for a normal adult.
When the bladder is full signals are sent to the brain and you feel the need to urinate. The urination process is controlled by circular (sphincter) muscles that relax to let urine flow through the urethra and out of the body.
Water Consumption
It is important to regularly consume water throughout the day, most experts recommend that you drink around 8 glasses of water (2 litres) to maintain healthy kidneys. If you do not drink enough water throughout the day the body struggles to flush all the waste products in an effort to preserve water levels.
Lack of water can make you susceptible to cystitis or kidney infections (pyelonephritis) and could lead to renal problems later in life if you do not look after the health of your kidneys and bladder. This is especially true in children because their renal and urinary systems are still developing.
- Kidneys use water to flush waste products from the blood stream
- The bladder stores urine before it is excreted by the body
- Lack of water leads to concentrated urine
- Could cause kidney & bladder illnesses.
