Kidneys play an essential role in maintaining the body’s homeostasis. These organs help filter out the waste products in the body and regulate the body’s fluid and the blood’s pH.

The **kidney** is the main organ of the excretory system and it is found on either side of the spinal cord near the lower area. This organ is composed of many functional units called *nephrons* which function to filter the blood and reabsorb the necessary nutrients.

The nephron filters the blood and removes its impurities, creating the so-called **filtrate**, which is then emptied out to the collecting duct before it will be excreted out in the body. The filtered or purified blood on the other hand is traveled back to the body through the venule via the *reabsorption* process.

The kidney, which is composed of nephrons, has two regions that include the inner part called the renal medulla and the outer part known as the renal cortex. For the purpose of protecting these regions, the kidneys are enclosed in a renal capsule and some layers of fat.

The sweat glands found in the skin serve an excretory function by secreting sweat or perspiration. In this way, the level of the salt in the body is maintained and the waste products are excreted from the body.

**Diuretics** are substances that help our body to remove salt, especially sodium and excess water. These substances are used to regulate and manage some disorders including edema, hypertension, and heart failure. These substances make the patient pee frequently, thus helping the body most especially the kidneys and the heart to remove the unnecessary substances.