Body Fluid Components Flashcards
How many litres of fluid is found in the plasma, intersitual fluid and intracellular fluid
Plasma - 3L
Interstitial fluid - 11L
Intracellular fluid - 28L
How many of litres of fluid are in the blood?
Approx 5L in an average body
Describe the features of the extracellular fluid compartment
Approx 14 litres (3 plasma and 11 interstitual) Plasma and interstitiual fluid (IF) have almost the same composition except for proteins. Plasma and IF exchange substances through highly permeable membranes except most proteins are too large to exchange so there is a higher conc in plasma then IF
Describe some of the features of intracellular fluid compartment
It is approx 28 litres separated from the ECF by membranes that are highly permeable to water but not electrolytes.
Entry and exit of substances is crucial for life.
There is low Na and CL and high proteins and K, this is important for physiological processes
Explain the levels of ions in the ICF and ECF
In the ECF - 140mM of Na, 110mM of Cl and 5mM of K
In the ICF - 5mM of Cl, 15mM of Na and 140mM of K.
What are the three types of membrane proteins?
Integral, peripheral and lipid anchored proteins.
Define ampipathic?
It means the phospholipid has both hydrophobic and hydrophilic properties
What are the three types of membrane lipids
Phospholipids - These form the basic hydrophobic/hydrophilic bilayer
Spingolipids - contains amino alcohols and have hydrophilic and hydrophobic characters. In most membranes, especially nerves.
Cholesterol - Dissolved in the membrane and contributes to fluidity.
Describe the membrane proteins involved in transport
Channel - Have watery spaces in through the molecule that allow free movement of water, some molecules and ions
Carrier - bind to molecules or ions and move them across the membrane via the protein.
Describe the different ways of membrane transport
It may be passive (down a concentration gradient)
It may be active;
Primary active transport uses energy directly. Secondary active transport uses the energy indirectly
What can the rate of transport of be influenced by?
Concentration, electrical potential and pressure
Describe how concentration effects transportation
Molecules will be transported along the concentration gradient
What is net diffusion?
It is proportional to the concentration difference across a membrane
Describe how effects of electrical potential on diffusion of ions
Electrical potential drives the movement of ions to the opposite pole. Movement can occur against a concentration gradient
Describe the effects of pressure differences across the membrane
Pressure differences across the membrane increases the diffusion.
