The kidney is a vital organ in the human body responsible for filtering blood, removing waste products, and regulating various physiological processes. Each human typically has two kidneys, and they are located on either side of the spine, below the ribcage. Here is an overview of the structure of the kidney:
- Renal Cortex:
- The outermost layer of the kidney is called the renal cortex.
- It contains renal corpuscles, which include Bowman’s capsules and glomeruli.
- Renal Medulla:
- Beneath the renal cortex is the renal medulla.
- The medulla is organized into renal pyramids, which are cone-shaped structures.
- Each pyramid has a base facing the cortex and a tip (renal papilla) pointing toward the renal pelvis.
- Renal Pelvis:
- The renal pelvis is a funnel-shaped structure that collects urine from the nephrons.
- It is located at the innermost part of the kidney, towards the hilum.
- Renal Hilum:
- The hilum is a concave notch on the medial side of the kidney, where the renal artery, renal vein, and ureter enter and exit the organ.
- Nephrons:
- Nephrons are the functional units of the kidney responsible for filtering blood and forming urine.
- Each kidney contains over a million nephrons.
- A nephron consists of a renal corpuscle (Bowman’s capsule and glomerulus) and a renal tubule (proximal convoluted tubule, loop of Henle, and distal convoluted tubule).
- Renal Artery and Vein:
- The renal artery brings oxygenated blood to the kidney for filtration.
- The renal vein carries filtered and deoxygenated blood away from the kidney.
- Ureter:
- The ureter is a muscular tube that connects the kidney to the urinary bladder.
- It transports urine from the renal pelvis to the bladder.
- Renal Capsule:
- The kidney is surrounded by a fibrous, protective layer called the renal capsule.
- Perirenal Fat:
- Adipose tissue surrounds the kidney and provides cushioning and protection.
- Renal Sinus:
- The renal sinus is a cavity within the kidney that contains blood vessels, nerves, and lymphatic vessels.
The kidneys play a crucial role in maintaining the body’s internal environment by regulating electrolytes, fluid balance, and blood pressure. They also contribute to the production of hormones such as erythropoietin and renin.
