A Brief Study About the Kidney and Urinary Tract Biology

Under normal circumstances, humans have two kidneys. Each kidney has a ureter that drains urine from the renal pelvis (the kidney is central to the collection of urine) into the bladder. From the bladder, urine flows through the urethra, leaving the body through the penis (male) and vulva (women).

Kidney function is to:

* Filtering of metabolic waste
* Filter out excess sodium and water from the blood
* Helps remove waste products and excess sodium and water from the body
* Helps regulate blood pressure
* Helps regulate blood cell formation.

Each kidney consists of about 1 million filtering units (nephrons). A nephron is a structure that resembles a bowl with a perforated wall (Bowman's capsule), which contains a tuft of blood vessels (glomeruli). Bowman's capsule and glomerular renal korpuskulum form.

Blood entering the glomerulus has a high pressure. Most of the liquid part of blood that is filtered through tiny holes in the walls of blood vessels in the lining of the glomerulus and Bowman's capsule; so the only remaining blood cells and large molecules (eg proteins).

The fluid was filtered (filtrate) into the cavity of Bowman (areas located between the inner layer and outer layer of Bowman's capsule) and flows into the proximal convoluted tubule (tube / channel upstream from the Bowman's capsule); sodium, water, glucose, and other materials that come filtered reabsorbed and returned to the blood.

The kidneys also use energy to selectively move large molecules (including drugs, eg penicillin) into the tubule. The molecule is discharged into the urine, although its size is large enough to be able to pass through the holes in the glomerular filter.

The next part of the nephron is Ansa Henle. When the liquid through the Ansa Henle, sodium and some other electrolyte is pumped out so the remaining liquid becomes more concentrated. This concentrated liquid that will flow into the distal convoluted tubule. In the distal tubules, the more the amount of sodium is pumped out.

Fluid of some nephron flow into a collecting ducts (collecting ducts). In the collecting ducts, the fluid passes through the kidneys as a concentrated liquid, or if it is still runny, then the water will be absorbed from the urine and returned to the blood, so that the urine becomes more concentrated. The body controls the concentration of the urine based on its needs for water through the hormones that affect kidney function works.

Urine that form in the kidneys flows down through the ureters into the bladder; flow is not a passive flow. The ureter is the tube / muscular tube that drives a number of urine in a wavy motion (contraction). Each ureter will get into the bladder through a sphincter. Sphincter is a muscular structure (muscular) that can be opened (so that urine can pass) and close.

Urine that regularly flow from the ureter will collect in the bladder. This could inflate the bladder, where its size is gradually enlarged to accommodate the amount of urine increased. If the bladder is full, it will send nerve signals to the brain, which convey messages to urinate.

During urination, another sphincter located between the bladder and urethra will be open so that urine flows out. Simultaneously, the bladder wall to contract, causing pressure to push urine into the urethra. This pressure can be magnified by tightening the abdominal muscles. Sfinger at the entrance of the bladder remains shut to prevent backflow of urine into the ureters.