Various Types of Human Kidney Structures

Description: The fibrous renal capsule is connective tissue that creates a tough fibrous layer around the kidney. It is covered in fat tissue called peri-nephric fat. These layers cushion and protect the kidney from damage.

Description: The renal cortex is the outer portion of the kidney. Often smooth on the outside, the cortex has projections known as cortical columns between the pyramids of the kidney. The cortex contains the corpuscles and tubules, but not the loops of Henle which enter the medulla. The cortex is also where the blood vessels and cortical collecting ducts are found and where ultrafiltration occurs.

Description: The renal medulla is the core of the kidney. The human renal medulla contains 10-20 renal pyramids, or sections. The renal artery enters the medulla through the hilus of the kidney. The renal tubules connect the medulla and cortex.

Description: Renal pyramids are sections of cone shaped tissue in the kidney. The base is in the cortex and the apex points inward to the medulla. The pyramids are made of nephrons, the basic functional unit of the kidney.

Description: The nephron is the basic structural and functional unit of the kidney. Making up the structures known as the renal pyramids, nephrons filter waste from the blood and maintain fluid and electrolyte balance via a series of tubules and ducts that weave around blood vessels and wind through the cortex and medulla of the kidney. Nephron function is regulated by endocrine hormones.

Description: The renal corpuscle is the initial filtering component of a nephron, the functional unit of the kidney. The corpuscle is made up of two structures called the glomerulus and the Bowman's capsule. The glomerulus is a capillary extension that receives blood from the renal circulation via an arteriole. The high pressure in the glomerulus pushes water and solutes into a space outside the blood vessel. The space is protected by the Bowman's capsule. The fluid then proceeds to the renal tubule.

Description: The renal tubule is the portion of the nephron, the basic functional unit of the kidney, which carries filtered fluid from the glomerulus to the collecting ducts. In the process, parts of the tubule act on the fluid to further filter the waste and maintain balance by reabsorbing water, salts, glucose, and amino acids. The parts of the tubule include the proximal tubule, the loop of Henle, and the distal convoluted tubule.

Description: The collecting ducts are the final portion of the nephron, the basic functional unit of the kidney. Fluid that has been filtered and concentrated by the corpuscle and tubule enters the beginning of the collecting duct system, the collecting tubule. The system extends through both the renal cortex and medulla. Under the control of antidiuretic hormone (ADH) the ducts become permeable or impermeable to water in order to either concentrate or dilute the urine as needed by the body. Lower portions of the collecting ducts are also permeable to urea, the nitrogen containing component of urine.

Also known as: Renal calyces (plural)

Description: The renal calyx is a structure in the kidney where urine drains from the nephron collecting duct system after it is filtered. Consistent muscular contractions, called peristalsis, force the fluid through the calyx into the renal pelvis.

Description: The renal pelvis is a funnel-like structure in the kidney. Urine is propelled out of the calyces into the pelvis where it drains into the ureter. The urine is then transported into the bladder where it is stored for urination.