Excretory Organ in the Human Body – Class 10

Excretory Organ in the Human Body:

The main excretory organ in the human body is the kidney. Kidneys play a vital role in filtering waste products and extra substances from the blood, helping to keep the body’s fluids, electrolytes, and minerals balanced. Humans have two kidneys, and the study of kidneys is called nephrology, with doctors specializing in this field known as nephrologists.

Kidney Development:

Kidneys begin to form in the 7th month of pregnancy. They are located in an area called the retroperitoneal space, which is behind the abdominal cavity. The right kidney sits lower than the left kidney because the liver takes up space on the right side of the body.

Kidney Structure:

Kidneys are bean-shaped and reddish-brown. They are located on either side of the spine in the lower abdomen. Each kidney is about 10-14 cm long, 8-10 cm wide, 4-5 cm thick, and weighs between 100-150 grams. Inside each kidney, there are around one million nephrons, which are tiny filtration units about 3 cm long. These nephrons help the kidneys continuously filter the blood and form urine.

Functions of the Kidneys:

– Filtering Waste: Kidneys filter the blood to remove waste produced during metabolism.

– Maintaining Water and Ion Balance: They help maintain the right amount of water and ionic balance in the body, which is known as osmoregulation.

– Hormone Secretion: Kidneys release a hormone called erythropoietin and an enzyme called renin.

– Vitamin D Activation: They convert inactive vitamin D into its active form, which is important for bone health.

– Blood Pressure Regulation: By controlling fluid levels, kidneys help regulate blood pressure.

The kidneys are essential for overall health, and damage to these organs can lead to serious health issues. They perform many important functions, from filtering waste to producing hormones and regulating blood pressure.