What Does Countercurrent Mean?

What is countercurrent flow in fish?

Fish also have an efficient transport system within the lamellae which maintains the concentration gradient across the lamellae.

The arrangement of water flowing past the gills in the opposite direction to the blood (called countercurrent flow) means that they can extract oxygen at 3 times the rate a human can..

What is an example of countercurrent exchange?

Venous blood recovers heat from the arterial blood as the former warms on its way back to the body. Blood vessels in the neck also employ a countercurrent arrangement and that results in a brain temperature about 1°C cooler than that of the body. (A countercurrent exchange of blood oxygen occurs in the gills of fish.)

What is the purpose of countercurrent exchange?

The purpose of counter current exchange is to maintain a concentration gradient between the two fluids in order to maximize movement from one fluid to the other. The opposite of counter current exchange occurs in concurrent exchange when two fluids flow in the same direction.

What are the advantages of countercurrent flow?

In contrast, countercurrent oxygen exchange allows the blood to pick up 90 percent of the oxygen in the water. This impressive ability to acquire oxygen allows fish to thrive in water that has oxygen levels only a tenth of those at the top of Mount Everest, where most people cannot survive without supplemental oxygen.

Where is countercurrent exchange found in the body?

Countercurrent multiplication has been found in the kidneys as well as in many other biological organs.

Why are fish gills rich in blood?

The water enters the mouth and passes through the feathery filaments of the fish’s gills, which are rich in blood. These gill filaments absorb oxygen from the water and move it into the bloodstream. The fish’s heart pumps the blood to distribute the oxygen throughout the body.

What is countercurrent exchange in the kidneys?

Countercurrent multiplication in the kidneys is the process of using energy to generate an osmotic gradient that enables you to reabsorb water from the tubular fluid and produce concentrated urine.

Do lungs use countercurrent exchange?

Therefore, oxygen has a diffusion rate in air 10,000 times greater than in water. The use of sac-like lungs to remove oxygen from water would therefore not be efficient enough to sustain life. … Gills use a countercurrent flow system that increases the efficiency of oxygen-uptake (and waste gas loss).

Do humans use countercurrent gas exchange?

Countercurrent exchange uses Diffusion to passively (no energy required) transfer the oxygen across to the blood. … Fish have lower metabolic rates than humans, and so their oxygen requirements are much lower than mammals and can live without hemoglobin.

How do gills promote gas exchange?

Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. In some fish, capillary blood flows in the opposite direction to the water, causing counter-current exchange. The gills push the oxygen-poor water out through openings in the sides of the pharynx.

What does countercurrent flow mean?

This is the way that a fish’s gills absorb the maximum amount of oxygen from the water. Water flows in the opposite direction to the blood flow in the gills to ensure that there is always a higher concentration of oxygen in the water than the concentration of oxygen in the blood.

What is countercurrent exchange in 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.

Why do fish swim against the current?

In nature, a fish must exert energy and swim against the current to avoid being swept downstream. In the aquarium the fish moves in the same direc- tion as the moving card, which might be viewed as a fixed object in the stream.

Why do fish need gas exchange?

Living organisms need energy from respiration to survive and reproduce. Gas exchange is when oxygen is taken from the air or water and into the bloodstream, and carbon dioxide is released. Fish are vertebrates which all require oxygen (O2) to survive, and they carry out gas exchange in water as this is their habitat.

What is the difference between plants and animals in terms of gas exchange?

Animals obtain their glucose,by breakdown of carbohydrates in diet,while plants photosynthesize their glucose. Again,animals obtain oxygen by breathing air,while plants release oxygen,as a by-product of photosynthesis. … This type of respiration is absent in plants.