What is the difference between renal corpuscle and glomerulus

The term forming urine will be used hereafter to describe the filtrate as it is modified into true urine. The principle task of the nephron population is to balance the plasma to homeostatic set points and excrete potential toxins in the urine. They do this by accomplishing three principle functions—filtration, reabsorption, and secretion.

They also have additional secondary functions that exert control in three areas: blood pressure via production of renin , red blood cell production via the hormone EPO , and calcium absorption via conversion of calcidiol into calcitriol, the active form of vitamin D. The glomerulus is a high-pressure capillary bed between afferent and efferent arterioles. It transitions onto the glomerular capillaries in an intimate embrace to form the visceral layer of the capsule.

Here, the cells are not squamous, but uniquely shaped cells podocytes extending finger-like arms pedicels to cover the glomerular capillaries Figure 1. Figure 1. Podocytes interdigitate with structures called pedicels and filter substances in a way similar to fenestrations. In a , the large cell body can be seen at the top right corner, with branches extending from the cell body. The smallest finger-like extensions are the pedicels. Pedicels on one podocyte always interdigitate with the pedicels of another podocyte.

These projections interdigitate to form filtration slits , leaving small gaps between the digits to form a sieve. These three features comprise what is known as the filtration membrane.

This membrane permits very rapid movement of filtrate from capillary to capsule though pores that are only 70 nm in diameter. Figure 2. Fenestrations allow many substances to diffuse from the blood based primarily on size. The fenestrations prevent filtration of blood cells or large proteins, but allow most other constituents through.

These substances cross readily if they are less than 4 nm in size and most pass freely up to 8 nm in size. An additional factor affecting the ability of substances to cross this barrier is their electric charge. The proteins associated with these pores are negatively charged, so they tend to repel negatively charged substances and allow positively charged substances to pass more readily.

The basement membrane prevents filtration of medium-to-large proteins such as globulins. There are also mesangial cells in the filtration membrane that can contract to help regulate the rate of filtration of the glomerulus. Overall, filtration is regulated by fenestrations in capillary endothelial cells, podocytes with filtration slits, membrane charge, and the basement membrane between capillary cells.

The result is the creation of a filtrate that does not contain cells or large proteins, and has a slight predominance of positively charged substances. This cluster of cuboidal epithelial cells monitors the fluid composition of fluid flowing through the DCT. They also have a single, nonmotile cilium that responds to the rate of fluid movement in the tubule. Figure 3. A second cell type in this apparatus is the juxtaglomerular cell.

This is a modified, smooth muscle cell lining the afferent arteriole that can contract or relax in response to ATP or adenosine released by the macula densa. Numerous collecting ducts merge into the renal pelvis, which then becomes the ureter. The ureter is a muscular tube, composed of an inner longitudinal layer and an outer circular layer. The lumen of the ureter is covered by transitional epithelium also called urothelium. Recall from the Laboratory on Epithelia that the transitional epithelium is unique to the conducting passages of the urinary system.

Its ability to stretch allows the dilation of the conducting passages when necessary. The ureter connects the kidney and the urinary bladder. The ureter empties the urine into the bladder. The transitional epithelium continues over the surface of this organ. The thickened muscular layers become interwoven and cannot be clearly identified at this point.

The urethra carries the urine away from the bladder to the outside of the body. In the male, it is joined by the genital system. The epithelium changes from transitional to stratified or pseudostratified columnar in the urethra, and to stratified squamous in the distal end of the urethra. Answer: Podocyte: Foot processes assist in filtration barrier function by repelling negatively-charged molecules. Mesangial Cell: Provides structure support and regulate diameter of capillaries.

Macula Densa: Senses blood pressure, regulates blood flow in afferent arteriole to maintain the glomerular filtration rate and stimulates release of renin. Juxtaglomerular Complex: synthesize, store and release renin. Answer: The ureter and bladder have a transitional epithelium. The initial segment of the urethra has a stratified epithelium, and the final segment has a stratified squamous epithelium.

Slides Please select whether to view the slides in study mode or quiz mode. In study mode, the images will contain labels and a description. In quiz mode, labels and description will be hidden. Study Mode. Virtual Microscope Slides Kidney Begin by identifying roughly where the renal cortex and renal medulla are located. Ureters are tubes that propel urine from the kidneys to the urinary bladder.

Examine the epithelium and two layers of smooth muscle. The urinary bladder collects and stores urine. Examine the epithelium and smooth muscle. Pathology Please select whether to view the slides in study mode or quiz mode. Quiz Why might one want a transitional epithelium in this region? Answer: Stretching capability. The cells that lies between glomerulus capillaries are called mesangial cells.

Podocytes are wrapped around the glomerulus capillaries by their foot-like structures. The structure of the renal corpuscle is shown in figure 1.

Filtration of blood is the main function of the renal corpuscle. Red blood cells , white blood cells , platelets and large proteins such as fibrinogens remain inside glomerulus capillaries. Renal tubule refers to the long convoluted tubules, which transports urine from the glomeruli to the renal pelvis. It produces urine from the plasma filtrate. The structural parts of the renal tubule are the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and the collecting duct.

Different types of molecules are reabsorbed in the different parts of the renal tubule. Proximal convoluted tubule is located in the renal cortex and it mainly reabsorbs water, glucose , amino acids , and ions. The loop of Henle penetrates to the renal medulla. The descending limb of the loop of Henle reabsorbs water while the ascending limb of the loop of Henle reabsorbs sodium ions and chloride ions.

The distal convoluted tubule is located in the renal medulla and it reabsorbs water and ions such as sodium, calcium, and chloride.