How is urine formed?

 

Urine analysis

Is simply an analysis of the urine it is a very common test that can be performed in many health care setting including doctors  office urgent care facilities laboratories and hospitals.

Analyzing urine was actually the beginning

Of laboratory medicine references to. The study of urine can be found in the drawings of cavemen and in Egyptian hieroglyphics

Urine formation and composition. 

• The kidney continuously form urine as an ultrafiltrate of plasma 

• Reabsorption of water and. Filtered substance essential. To body. Function converts approximately 170.000 ml of Filtered plasma to the average daily urine output of 1200 ml. 

• In order to produce urine the kidney do not simply pick waste products out of the blood stream and send them along for final disposal

• The two million or more nephrons form urine by three precisely regulated process 1-filteration 2-reabsorption 3-secretion. 

 1-filteration

Blood enter the afferent arteriole and flows into the glomerulus where filterable blood

Components such as water and nitrogenous waste will move towards the inside of the glomerulus  and non filtrate component such as cells will exit via the efferent arteriole these filtrate accumulate 

In the glomerulus to form glomerular filtrate. 

2-reabsorption

 during which molecules and ions, will be reabsorbed back in to the circulatory system 

What remains in the glomerulus after this process has taken place is known as the tubular fluid and this is what will pass through to the collecting duct to form urine 

3-secretion

Some substances such as hydrogen ions creatinine and Drugs will be removed from blood to form the urine. 

In general urine consists off urea and other organic and inorganic chemicals dissolve it in water

Urine is is normally 95% water and 5% solute although considerable variations in the concentrations of solute can you occur owing to the influence of factors such as dietary intake physical activity body metabolism and endocrine functions 

Urea a metabolic waste product produced in the liver from they break down of protein and amino acids accounts for nearly half of the total dissolved solids in urine

Other organic substances include primary creatinine and uric acid the major in organic solids dissolved in urine is chloride followed by sodium and potassium small or trace amount of many additional in organic chemicals are also present in urine

Other substances found in urine include hormones vitamins and medications

Although not  apart  of original plasma filtrate the urine also may contain formed elements such as Casts crystals mucus and bacteria 

increased amounts of this formed elements are often indicative of diseases.

The presence of squamous epithelial cell and the mucus in urine from woman can result in hazy but normal urine

Specimen that are allowed to stand or are refrigerated also may develop the turbidity that is non-pathologic  improper preservation of specimen result in bacterial growth  this increase specimen but is not representative of the actual specimen

Refrigerated specimen frequently develop a thick turbidity caused by the precipitation of amorphous phosphates carbonates and urates.

Additional nonpathological causes of urine turbidity include semen, fecal contamination ,radiographic contrast media ،talcum powder and vaginal creams.