I am a student, slightly struggling with the new concept of fluid compartments. I know that there are two main types of fluid compartment, extra and intracellular fluid. I also read that most organs need to have these fluid compartments (established by cell-cell adhesions within tissues) in order to function and develop properly. My question is what type of organs require these fluid compartments? Would it be the kidneys and the intestines for example? thanks
Organs consist of different tissues and cells. To function properly each cell needs intracellular fluid. All cellular processes (energy metabolism, signal transduction) occur in aqueous environment, otherwise the required chemical reactions could not take place. Extracellular fluids provide nutrients to the cells and also information from other cells or organs. It can be divided in three categories:
- Interstitial compartment: between tissue cells; provides nutrients and helps the cells to communicate within a tissue or organ.
- Intravascular compartment: content of blood vessels; transports nutrients, information and immune cells within the body e.g. from one organ to another.
- Transcellular compartment: all spaces in the body where only a small amount of fluid is present, normally between organs.
So all organs need these fluid compartments to function properly. The only organ where this is different is the skeleton. But the bone building cells (Osteoblasts) also need extra and intracellular fluid to build a scaffold of collagen. Only after that, they can fill up the interstitial space with hydroxylapatite. The kidneys clean up the blood and excrete the waste via the urine which occurs in aqueous environment. The intestinal tract absorbs nutrients which are solved in water. Hence, saliva and gastric juice are produced when you ate something.
So every organ needs fluid compartment to do its job. So does the whole organism to make sure all organs are working together (via blood circulation and nervous system).