A countercurrent system is characterized by very close contact of arterial blood vessels, ideally capillaries, with venous vessels returning from the tissue.
What is currents and counter current?
Equatorial countercurrent, current phenomenon noted near the equator, an eastward flow of oceanic water in opposition to and flanked by the westward equatorial currents of the Atlantic, Pacific, and Indian oceans. … The Pacific Equatorial Countercurrent is very strong and is definable year-round.
What is meant by counter current flow?
Countercurrent means flowing in opposite directions to increase contact. COLLOCATIONS: ~ flow. The most efficient way to transfer heat between two fluids is to have countercurrent flow.
What is counter current dialysis?
Hemodialysis removes blood and passes it through an extracorporeal circuit and an artificial membrane, with dialysate running in countercurrent flow next to the blood in the membrane. After the blood is filtered through the membrane, it is returned to the body with a reduced quantity of metabolic waste products.
What is counter current mechanism used for?
The countercurrent multiplier, or counter-current mechanism, is used by the nephrons of the human excretory system to concentrate urine in the kidneys.
Why is it called counter current mechanism?
Because the blood flow through these capillaries is very slow, any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid, which maintains the solute concentration gradient in the medulla. This passive process is known as countercurrent exchange.
What is counter current heat exchange?
countercurrent heat exchange A counterflow mechanism that enables fluids at different temperatures flowing in channels in opposite directions to exchange their heat content without mixing. … This helps to maintain the core temperature in freezing conditions.
What are Countercurrents and undercurrents?
Countercurrents flow on the surface in the opposite direction from the main currents. Undercurrents are countercurrents that flow beneath the surface current.
Where is Tsushima Current?
Tsushima Current, surface oceanic current, the northeastward-flowing branch of the Kuroshio along the west coast of Japan. Entering the Sea of Japan through the Korea Strait, the Tsushima Current issues the East Korea Warm Current as a northern branch.
How does counter current exchange work?
Fish gills use a design called ‘countercurrent oxygen exchange’ to maximize the amount of oxygen that their blood can pick up. They achieve this by maximizing the amount of time their blood is exposed to water that has a higher oxygen level, even as the blood takes on more oxygen.
Why is counter current flow more efficient?
Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path.
What is counter current flow in gills?
Fish transfer oxygen from the sea water to their blood using a highly efficient mechanism called countercurrent exchange. Countercurrent exchange means the flow of water over the gills is in the opposite direction to the flow of blood through the capillaries in the lamellae.
What is the importance of counter current?
Countercurrent flow produces the maximum concentration difference over the entire length of the membrane and allows recovery of a substantial portion of the most highly diffusive solute while minimizing the transport of the less diffusive solutes.
What is co current and counter current flow?
co-current flow means when two liquids let say A and B both move in same direction let say from right to left or vice versa. while counter current flow means both liquids move in opposite direction to each other for e.g. liquid A moves ffrom right to left and liquid B moves from left to right.
What is the purpose of dialysate?
Dialysate is a fluid that is made up of water, electrolytes and salts. During dialysis, dialysate helps to clean your blood inside the dialyzer by removing waste products and balancing electrolytes. Your nephrologist will prescribe the dialysate that is right for your body’s needs.
Do Juxtamedullary nephrons have peritubular capillaries?
In the juxtamedullary nephrons, the peritubular capillaries have a specialization called the vasa recta, which are long, hairpin-shaped blood vessels that follow the same course as the loop of Henle. The vasa recta serve as osmotic exchangers for the production of concentrated urine.
How does the kidney concentrate urine?
In the presence of ADH, the medullary collecting ducts become freely permeable to solute and water. As a consequence, the fluid entering the ducts (en route to the renal pelvis and subsequent elimination) acquires the concentration of the interstitial fluid of the medulla; i.e., the urine becomes concentrated.
Why urea is reabsorbed?
Urea, in addition to sodium contributes for maintenig the hyperosmolarity in the medulla, so to reabsorb water. … The urea reabsorbtion enable the formation of a high-osmolar urea gradient in the renal medulla, which is important for the renal urine concentration.
What is counter current mechanism explain with diagram?
The countercurrent mechanism helps to concentrate the filtrate which occurs in the loop of Henle and vasa recta in the medulla region of the kidney. The flow of fluids in opposite directions is maintained by their flow in the two loops- ascending and descending limbs of the loop of Henle and vasa recta.
What is a counter current multiplier system?
countercurrent multiplier system An active process occurring in the loops of Henle in the kidney, which is responsible for the production of concentrated urine in the collecting ducts of the nephrons.
What is the loop of Henle?
loop of Henle, long U-shaped portion of the tubule that conducts urine within each nephron of the kidney of reptiles, birds, and mammals. … This function allows production of urine that is far more concentrated than blood, limiting the amount of water needed as intake for survival.
What is counter current mechanism in fish?
Counter current exchange is the mechanism in which oxygen enters the blood in fish. Blood flows in the opposite direction to the water that flows over the fish’s gills. Fish gills have gill filaments and these filaments have protrusions called lamellae which the water flows over.
Why are equatorial currents important?
The equatorial countercurrent plays an important role in the circulation of mass, heat, and salt in the tropical oceans. It provides one of the pathways through which warm surface water returns eastward after being transported westward in the South Equatorial Current.
Why there is counter equatorial current?
Theoretical Background. The NECC is a direct response to the meridional changes in the coriolis parameter and the wind stress curl near the Intertropical Convergence Zone (ITCZ). In part the NECC owes its existence to the fact that the ITCZ is not located at the equator, rather several degrees of latitude to the north.
What causes the Cromwell current?
The cause of the pressure gradient is at least partially the trade winds blowing from the east westward. (b) Any water parcel flowing eastward from the west that would somehow be perturbed from its path would be diverted northward if north of the equator and southward if south of the equator.
Is Labrador a cold current?
Originating at the Davis Strait, the Labrador Current is a combination of the West Greenland Current, the Baffin Island Current, and inflow from Hudson Bay. The current is cold and has a low salinity; it maintains temperatures of less than 32° F (0° C) and salinities in the range of 30 to 34 parts per 1,000.
Is there an equivalent to the Gulf Stream in the Pacific?
The Kuroshio Current is the Pacific analogue of the Gulf Stream in the Atlantic Ocean, transporting warm, tropical water northward toward the polar region.
Why Kuroshio Current is warm?
The surface waters of the Kuroshio Current are warm and salty. This is because the Kuroshio starts in the tropics where the westward flowing North Equatorial Current reaches the western boundary of the North Pacific. … The streaks of warm water can be clearly seen in satellite images in spring.
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.