What is a countercurrent exchange in a body?
Countercurrent Heat Exchange. Countercurrent Heat Exchange. Blood flowing from the body core to the periphery (like the legs & feet) carries heat that can be readily lost through the skin. However, the vein returning blood to the body core lies alongside the artery taking blood to the feet.
What is countercurrent exchange biology?
A biological mechanism in which there is an exchange of a substance between fluids flowing in opposite directions. Engineers have known that efficient and almost complete heat or other exchange could be achieved between two fluids flowing in opposite directions in separate tubes.
What are countercurrent exchangers and why are they important in biology?
a biological mechanism designed to enable maximum exchange between two fluids. Such mechanisms occur, for example, in oxygen exchange between water and the blood vessels in fish gills, and in the ascending and descending tubules of the LOOP OF HENLE in the mammalian kidney. …
Which of the following is an example of a counter current exchange?
For example, fish use it in their gills to transfer oxygen from the surrounding water into their blood, and birds use a countercurrent heat exchanger between blood vessels in their legs to keep heat concentrated within their bodies.
What is counter current exchange in thermoregulation?
A countercurrent heat exchanger is an arrangement of blood vessels in which heat flows from warmer to cooler blood, usually reducing heat loss. Some animals use body insulation and evaporative mechanisms, such as sweating and panting, in body temperature regulation.
Why is counter current better?
One of the great advantages of counter-current flow is the possibility of extracting a higher proportion of the heat content of the heating fluid. It is important to note that the LMTD value for counter-current flow is much larger than for cocurrent flow at the same terminal temperature (see Figure 1.9).
Why is counter current exchange more efficient?
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.
Do ectotherms Thermoregulate?
Ectotherms usually live in environments in which temperatures are constant, such as the tropics or ocean. Ectotherms have developed several behavioral thermoregulation mechanisms, such as basking in the sun to increase body temperature or seeking shade to decrease body temperature.
Why is lmtd used?
The logarithmic mean temperature difference (also known as log mean temperature difference, LMTD) is used to determine the temperature driving force for heat transfer in flow systems, most notably in heat exchangers.
What is counter flowing flowing?
: the flow of a fluid in opposite directions (as in an apparatus)
Do lungs use a counter current system?
In a countercurrent flow system, air (or, more usually, the water containing dissolved air) is drawn in the opposite direction to the flow of blood in the gas exchanger. and dead-end air-filled sac systems found in the lungs of mammals.
Why is counter flow better than parallel flow?
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. Each time a fluid moves through the length is known as a pass.