Isn't it that cells are adjacent to each other? How come there is such thing as Extracellular fluid (ECF)?

Question

I'm confused.............Thanks

Answer 1

ECF has nothing to do with red blood cells or white blood cells. Particles that need to enter cells (ions, water, OXYGEN!!) do so by means of the ECF. These particles diffuse out of the lumen of blood vessels, into extracellular fluid, which bathes cells. They then enter cells from the ECF.

There are different types of cell cell junctions, including tight junctions, gap junctions, adherens, and desmosomes. The blood-brain barrier for example is an example of where tight junctions exist. Very few particles can pass through tight junctions, which is why the endothelial cells of the blood vessels form the blood-brain barrier.

Now, there is ECF bathing all cells, despite the junctions between them. Water, ions, and respiratory gases can all get through the blood brain barrier, otherwise our brain cells would die.

The ECF represents one component of the extra-cellular matrix (ECM), which is a series of mostly proteins, glycoproteins, and proteoglycans (all called "ground substance). All cells interact with the ECF and ECM!

Answer 2

It is why osmotic pressure is important as too much water can cause cell rupture. Look at your body as proteins, carbs, and fats in a water solution. I know it's simplistic and I'm leaving out the from ashes to ashes part.

Answer 3

blood plasma and interstitial fluid are ECFs.

so it's not true that all animal cells are adjacent to each other. red blood cells are free floating, so are white blood cells. there are spaces between some types of cells.

Answer 4

ECF is fluid not contined by a cellular barrier...for instance blood plasma is not cellular,so it is ECF

Answer 5

they are close together but there are still small gaps of space between them. it'd be the same as if a group of people stood really close together, there are still gaps here and there.