In the context of renal tubule physiology, the term basolateral membrane or serosal membrane refers to the cell membrane which is oriented away from the lumen of the tubule, whereas the term luminal membrane or apical membrane refers to the cell membrane which is oriented towards the lumen.
What is basolateral membrane of renal tubule?
A major function of renal tubules is the net transport of acid from the blood into the luminal fluid. To accomplish this, acid (H ions) is secreted from cell to lumen across the apical membrane, and base generated within the cell exits into the interstitium across the basolateral membrane.
What is lateral or basolateral membrane?
Basolateral membrane is a compound phrase referring to the terms basal (base) membrane and lateral (side) membrane, which, especially in epithelial cells, are essentially functionally identical in composition and activity.
What is the apical membrane?
The apical plasma membrane is defined as the region of the plasma membrane located. at the apex of the epithelial cell that is separated, in vertebrates, from the basal-lateral. region by a ring of tight junctions.
What is basolateral surface?
Medical Definition of basolateral : situated below and toward the side : located in or on the base and one or more sides Epithelia permit selective and regulated flux from apical to basolateral surfaces …— David B. Simon et al., Science, 2 July 1999.
Why is Transcytosis important?
Transcytosis is an important intracellular transport process by which multicellular organisms selectively move cargoes from apical to basolateral membranes without disrupting cellular homeostasis.
What do enterocytes do?
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. … This facilitates transport of numerous small molecules into the enterocyte from the intestinal lumen.
Where is basement membrane?
The basement membrane is a thin, pliable sheet-like type of extracellular matrix, that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tissues including mesothelium and endothelium, and the underlying connective tissue.
What is the purpose of the loop of Henle?
The primary function of the loops of Henle and the thick ascending limb of the distal tubule is the concentration of urine utilizing a principle called ‘countercurrent multiplication. ‘ The medulla possesses a gradient of urea and salt with increasing concentrations of these solutes closer to the papillae.
What is Pseudostratified columnar epithelium?
Pseudostratified columnar epithelium is a type of epithelium that appears to be stratified but instead consists of a single layer of irregularly shaped and differently sized columnar cells. … Pseudostratified columnar epithelium is found in the respiratory tract, where some of these cells have cilia.
What is Apico basal polarity?
Apicobasal polarity is a type of cell polarity specific to epithelial cells, referring to a specialised apical membrane facing the outside of the body or lumen of internal cavities, and a specialised basolateral membrane localised at the opposite side, away from the lumen.
Where is simple squamous epithelium found?
Simple squamous epithelium Simple squamous epithelia consist of a single layer of flattened cells. This type of epithelia lines the inner surface of all blood vessels (endothelium), forms the wall of alveolar sacs in the lung and lines the body cavities (mesothelium).
What is apical and basal?
The basal side of the cell is the side that faces the basement membrane, i.e. the connective tissue layer the cell lives on. The apical side is the side that faces the opposite direction, usually towards the lumen (inside) of a tube.
What is the difference between apical and basal?
The apical faces external environment or lumen of a tube where it is often involved in absorption or secretion. The basal mediates attachment to underlying tissue or surface via integrins.
What’s an apical surface?
The bottom edge of the epithelial tissue next to the basement membrane is the basal surface. In contrast, the edge of the epithelial tissue facing the lumen or the external environment is called the apical surface.
Is glucose movement across the basolateral membrane active or passive?
In a transport epithelial cell, transcellular transport of glucose is an active process, whereas the movement of glucose across the basolateral membrane occurs by passive facilitated diffusion.
What is the function of the epithelium Labster?
Epithelial tissue lines all organs and lumens in an animal’s body. Their role is to act as a barrier to protect the rest of the cells from environmental conditions such as sunlight, or the acid in the stomach.
What is epithelial cells in HPF in urine?
Epithelial cells naturally slough off from your body. It’s normal to have one to five squamous epithelial cells per high power field (HPF) in your urine. Having a moderate number or many cells may indicate: a yeast or urinary tract infection (UTI) kidney or liver disease.
What happens during transcytosis?
Transcytosis is the transfer of molecules across cells from one side to the other, a process that entails endocytosis, vesicular transfer and exocytosis, and which speeds the bulk movement of molecules through tissues.
What is a transcytosis system?
Transcytosis (also known as cytopempsis) is a type of transcellular transport in which various macromolecules are transported across the interior of a cell. Macromolecules are captured in vesicles on one side of the cell, drawn across the cell, and ejected on the other side.
Is transcytosis and endocytosis the same?
The key difference between endocytosis and transcytosis is that endocytosis is a cellular mechanism by which cells uptake materials inside the cell by invagination of the cell membrane and forming a vesicle surrounding the materials, while transcytosis is a cellular mechanism that transports various macromolecules …
What can enterocytes absorb?
Enterocytes in the small intestine absorb large amounts of sodium ion from the lumen, both by cotransport with organic nutrients and by exchange with protons. … This flow and accumulation of sodium is ultimately responsible for absorption of water, amino acids and carbohydrates.
What type of cell is enterocytes?
epithelial cell Enterocytes are the major villus epithelial cell type. They are highly specialized tall and columnar cells, with an oval nucleus located basally (Fig. 3).
Do enterocytes absorb water?
Water is always absorbed in the alimentary tract through passive osmosis via a mostly paracellular route between enterocyte tight junctions. Consequently, water absorption is primarily actuated by active absorption of osmotic electrolytes, especially sodium.
What is the basement membrane in the kidney?
The glomerular basement membrane of the kidney is the basal lamina layer of the glomerulus.
What is a basement membrane?
Basement membranes are thin layers of a specialized extracellular matrix that form the supporting structure on which epithelial and endothelial cells grow, and that surround muscle and fat cells and the Schwann cells of peripheral nerves.
What is function of basement membrane?
The basement membrane (BM) is a special type of extracellular matrix that lines the basal side of epithelial and endothelial tissues. Functionally, the BM is important for providing physical and biochemical cues to the overlying cells, sculpting the tissue into its correct size and shape.
What are the three major functions of the loop of Henle?
Other functions of the loop of Henle include:
- Homeostatic mechanisms to regulate the extracellular fluid volume.
- Regulating potassium, calcium and magnesium excretion at the lowest energy costs.
- Homeostasis of the acid-base balance via bicarbonate and ammonia excretion.
- Regulating the composition of urinary protein.
Why is it important that the loop of Henle passes into the medulla of the kidney?
By means of a countercurrent multiplier system, which uses electrolyte pumps, the loop of Henle creates an area of high urea concentration deep in the medulla, near the papillary duct in the collecting duct system. … This process reabsorbs water and creates a concentrated urine for excretion.
What is the importance of having a long loop of Henle and short loop of Henle in a nephron?
The counter-current system of the Loop of Henle is involved in the recovery of the water and NaCl from urine. The longer the Loop of Henle, the higher the osmolarity of the fluid as it contains more water. The short loops of the cortical nephrons passively reabsorb urea in the thick ascending limbs.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.