kidney- anatomy-physiology and sign of disease

The human kidney is a pair of reddish, bean-shaped organs that removed waste substances present in the blood. when blood enters the kidney, the useful substances are absorbed /filtered back into the blood. waste substances get dissolved in water and are removed as urine by two tubes called ureters, a urinary bladder that stores urine, and a urethra that removes the urine.

a normal human being excretes about 2 to 3 liters of urine in a day.

importance of the kidney in our body : 

Many, nitrogenous wastes such as urea and uric acid are formed inside our bodies. urea is formed by a combination of carbon dioxide and ammonia, it is excreted from the body in the form of pale yellowish-colored liquid (urine). urine contains urea, uric acid, and minerals. formation of urine takes place inside the kidney.

how our kidney work : 

 the kidneys are the basic filtration unit in the body. they have a cluster of very thin-walled blood capillaries. each capillaries cluster in the kidney is associated with the cup-shaped end of a tube that collects the urine, each kidney has large numbers of these filtration units called nephrons packed close together. some substances like glucose, amino acid, salts, and water are initial filtrate and reabsorbed. the urine forming in each kidney eventually enters a long tube(ureter) which connects the kidney with the urinary bladder. urine is stored in the urinary bladder until the pressure of the expanded bladder leads to the urge to pass it out through the urethra. the bladder is a muscular organ and under nervous control.

Sign of kidney disease :

Kidney disease usually affects both kidneys. If the kidneys do not work due to their general function due to any illness, then waste and excess fluid can be formed in the body. Although many forms of kidney disease do not produce symptoms until the time of illness, there are six warning signs of kidney disease:

• high blood pressure.
• Blood and/or protein in the urine
• A creatinine and blood urea nitrogen (BUN), in blood, exceeding the normal range. BUN (creatinine waste are those which occur in the blood when the kidneys function is reduced)
• A glomerulus filtration rate (GFR) is less than 60.
• Urine more frequent, especially at night; Hard or painful urination
• puffiness around the eyes,
• Swelling in hands and feet.

Some common term used in the excretory system :

nephrons: The kidney is made of a large number of excretory units called nephrons.

excretion: the process of removal of waste from the cells of a living organism.

urinary bladder - that stores urine.

urethra - that removes the urine.

ureters - two tubes from the kidney to the urinary bladder called ureters.