Lecture 7 - Water, Ions And Cell/tissue Fluid Balance Flashcards
What is osmosis?
The movement of a solvent across a semi permeable membrane toward a higher concentration of solute. When a cell is submerged in water, the water molecules pass through the cell membrane from an area of low solute concentration to high solute concentration
High to low concentrations is called?
Diffusion
Where is intracellular fluid located?
Inside the cell
Where is extra cellular fluid located?
Outside the cell
What is inside of fluid?
Ions, solutes and water
Water can be lost though what four things?
- Water vapor
- Lost in feces
- Sweat glands
- Urine
Isotonic means?
The ECF and ICF are in balance, with the two solutions isotonic
What happens if we lose water from the ECF?
Water loss from the ECF decreases volume and makes this solution hypertonic with respect to the ICF. The water moves from low concentrations of solutes to restore osmotic equilibrium
If the volume of ICF decreases what happens to the volume of ECF?
Decreased ICF volume = increased ECF volume - that cell is now going to shrink
ICF is larger in size and has a greater volume of water. What happens if we have a reduction of ICF?
If the volume of ICF is constantly reducing, it’ll try and balance that by moving water across. This can cause dehydration and in this process the cell will shrink
What happens to our cells if we have too much water?
If we have too much water, the volume of the ECF will increase. A lot of dilution of those solutes because there is more water for a given concentration. It will flow from the ECF to the ICF and the if the ICF volume increases, the inside of the cell will expand and be too plump
What happens when electrolytes hit the blood?
The electrolytes will dissociate and release ions
What is hypertonic solution?
A lot of water in the solution
What is hypertonic?
A lot of solute molecules in the solution?
Which ions do electrolytes dissociate and release when hitting the blood?
Sodium, potassium and calcium
Which tissues have excitable membrane potential?
Neurons and muscle tissue
Which cells have a membrane potential but are not excitable?
Epithelial cells
Both cations and anions are present inside and outside of cells. True or false?
True
What is resting membrane potential?
The distribution of ions creating the electricity
What are the levels of sodium and potassium outside the cell in ECF?
Sodium = high Potassium = low
What levels are sodium and potassium inside the cell in ICF?
Sodium = low Potassium = high
Plasma membrane has a lipid bilayer preventing the free flow of ions. What does this lipid bilayer do?
They can channel these ions through cations to maintain membrane potential or use an active transport potential. Passive flow = high to low
Why is the lipid bilayer flow passive?
It is passive as it relies on ATP, an energy molecule. Resting membrane is dependent on the chemical gradients from the active ATP process
