Structure and function of Kidney.(Zoology)-Biology.

Kidney is the pair structure primarily responsible for removal of waste product from the body in the form of urine.Kidney consist of million of small structure called nephron....

Describe the structure and function of human kidney.

The human kidney is a vital organ responsible for maintaining the body's fluid and electrolyte balance, regulating blood pressure, and filtering waste products from the blood to produce urine. We typically have two kidneys, located in the abdominal cavity on either side of the spine, just below the ribcage. The kidney has a bean-shaped structure, and each kidney is approximately the size of a fist. It is composed of three main regions: the renal cortex, renal medulla, and renal pelvis.

Renal Cortex:

This outermost region of the kidney contains millions of microscopic filtering units called nephrons. The renal cortex is responsible for filtering blood and removing waste products.

Renal Medulla:

The renal medulla lies beneath the renal cortex and consists of cone-shaped structures called renal pyramids. Each renal pyramid contains tiny tubules called collecting ducts, which collect urine produced by the nephrons.

Renal Pelvis:

 The renal pelvis is a funnel-shaped structure located at the innermost part of the kidney. It collects urine from the collecting ducts and transports it to the ureter, which carries urine to the bladder for storage and eventual elimination.

The functional unit of the kidney is the nephron. Each kidney contains around one million nephrons. A nephron consists of two main parts: the renal corpuscle and the renal tubule.

Renal Corpuscle:

The renal corpuscle is the initial site of blood filtration. It is composed of a network of tiny blood vessels called glomerulus, which is surrounded by a cup-like structure called Bowman's capsule. The glomerulus filters blood under high pressure, allowing small molecules such as water, electrolytes, glucose, and waste products to pass through into the renal tubule.

Renal Tubule:

The renal tubule is a long, coiled tube connected to Bowman's capsule. It has several segments, including the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. As the filtrate moves through the renal tubule, various processes occur to reabsorb necessary substances such as water, glucose, and electrolytes back into the bloodstream while allowing waste products and excess substances to remain in the tubule for excretion as urine.

Function of Kidney:

The kidneys play a crucial role in maintaining homeostasis by regulating the balance of water, electrolytes (such as sodium, potassium, and calcium), and acid-base balance in the body. They also produce hormones, including renin for blood pressure regulation and erythropoietin, which stimulates red blood cell production.