The primary function of human urinary system is to output waste products from the body and to maintain fluid/salt balance (rutgers.edu). These functions are realized through the specific structure of the system including two kidneys, two ureters, the bladder, and the urethra (VRP, 2012). The anatomy of each organ of urination corresponds to the function performed.
The Structure of Urinary System
Kidney is the primary organ of human urinary system which is situated in abdominal cavity. The organ consists of nephrons and the network of blood vessels facilitating its main function – filtering of wastes. The surrounding tissue – perinephric fat – protects kidney from mechanical damage.
The ureter is a membranous tube of approximately 25 cm long. The structure of this organ corresponds to its main function – to carry urine from kidney to bladder. Like kidney, ureter is a paired organ; though unlike living with one kidney, single-system ureteral ectopia requires less complicated treatment (Straticiue-Coingradi, et.al., 2010) and can be easily managed, especially when reveal in childhood.
In bladder, urine is accumulated and later released. It is located in the pelvic cavity and presents a multi-layer organ the size and shape of which depends on the amount of urine. The organ contains the network of nerves, the main function of which is to control the process of urination.
Urethra is a multi-layer tube which, however, differs in size in male and female. Female urethra is about 3-4 cm long, and its eternal orifice opens to vagina. Male urethra is longer – 20 cm – and apart from transporting urine it also takes part in reproduction by transporting semen.
The Role of Urinary System in Filtering Waste Products
When human body takes the nutrients from food, there is the need to remove wastes – urea - which, otherwise, will poison an organism. In kidneys, nephrons form the systems of renal pyramids which absorb wastes from the blood. Together with water, urea forms urine which is transported from kidney to ureters. The elastic muscle walls of ureters continuously tighten and relax pushing urine to the bladder. There, urine is stored and further released. Healthy bladder can store up to 16 ounces of urine for 2-5 hours (NIDDK, 2012).
The Role of Kidney in Managing Blood Pressure
Apart from performing waste accumulation function, the nephrons in kidney play significant role in controlling the amount of sodium in blood. According to the researchers at the University of Texas Health Science Centre, the amount of sodium in blood is under control of local regulatory system presented by distal nephrons (Health, 2011).
Consequently, nephrons in kidneys play vitally important role in preventing hypertension in humans. High blood pressure often results in more extensive work of the heart, which is an important risk-factor of most cardiovascular diseases, including myocardial infarction (Smith, et. al., 2006).
So, urinary system plays the primary role in releasing waste products from human blood and control over acid/electrolyte balance, so as to ensure the proper functioning of cardiovascular and other systems.
References
Kidney’s role vital in managing blood pressure. Health (Jan. 16, 2011). …