Filtration in medical terms refers to the process of separating substances from a fluid by passing it through a porous barrier. This barrier, often a membrane, allows certain substances to pass through while blocking others.
How Filtration Works in the Body
Our bodies use filtration extensively, particularly in the kidneys. Here's how it works:
- Blood enters the kidneys: Blood containing waste products and other substances flows through the kidneys.
- Filtration in the glomerulus: The blood passes through tiny filtering units called glomeruli. These glomeruli act like sieves, allowing small molecules like water, waste, and nutrients to pass into a structure called Bowman's capsule.
- Reabsorption: As the filtered fluid travels through the nephron (the functional unit of the kidney), most of the water and essential nutrients are reabsorbed back into the bloodstream.
- Excretion: Waste products and excess water are not reabsorbed and are excreted as urine.
Filtration in Medical Procedures
Filtration is also used in various medical procedures:
- Dialysis: This procedure filters blood for people with kidney failure.
- Blood transfusions: Blood is filtered to remove harmful substances before transfusion.
- Drug delivery: Some medications are administered through filtration systems, delivering targeted doses to specific areas of the body.
Examples of Filtration in the Body
- Filtering waste from the blood: The kidneys filter waste products like urea, creatinine, and excess salts.
- Filtering lymph fluid: The lymphatic system filters lymph fluid, removing waste products and microorganisms.
- Filtering air in the lungs: The respiratory system filters air, trapping dust and other particles in the mucous membranes.
Other Medical Uses of Filtration
- Sterilization: Filtration can sterilize solutions by removing bacteria and other microorganisms.
- Laboratory analysis: Filtration is used in laboratory testing to isolate and analyze specific components of fluids.
