Week 6 - Fluid And Electrolytes/Urinary System
No description yet. This curated deck is ready for daily study.
Card preview (24)
Functions of water
• acts as a solvent, allowing electrolytes to ionise • is a reagent in many chemical reactions • acts as a transport medium (eg blood) • is a lubricant (eg synovial fluid and mucus)
What are the two major fluid compartments in the body?
• intracellular fluid - extracellular fluid
Where is the intracellular fluid located in the body and what fraction is it in regards to the body’s fluid?
• located inside the cells (cytosol) - 2/3 of the bodies fluid
Where is extracellular fluid located in the body, and what fraction is it in regards to the body fluids?
• located outside of the cell - 1/3 of the bodies fluid
What type of fluid is plasma? And what is it known as?
Type of extracellular fluid, known as the third fluid compartment
Name some sources of fluid input
• food and drink - produced by cells
Name some Sources of fluid output
• kidneys as urine • lungs with expired air • skin by diffusion and by sweat • intestines as faeces
What happens if the body has excess water in it?
• excess water in the body causes over-hydration, and cells start to overfill
What happens if the cells start to overfill due to the excess water and over hydration?
• causes increased workload of the heart and shortness of breath (SOB) • may cause swelling of the neurons in the brain due to hyponatraemia
What happens if the body doesn’t have enough water (has insufficient water)
The body causes dehydration, and a drop in blood volume (therefore drop in blood pressure)
What happens when the body is in dehydration and there is a drop in blood volume?
• can cause decreased renal function and a decreased tissue perfusion
Describe the fluid movement
• water, other nutrients and waste products move from capillaries to interstitial spaces as a result of hydrostatic pressure - ‘pushing’ • water moves from the interstitial space into cells primarily as a result of osmosis - ‘pulling’ • proteins such as albumin play a large part in the osmotic “pull” of fluids and in the blood stream
Define osmolarity
Total solute concentration in a solution
Define Tonicity
Describes how the solution affects the cell
What is an isotonic solution?
Solutes and water in fluid and cells are equal • cells retain their size and shape • same osmolarity of blood plasma • if RBC are in isotonic solution, water molecules move in and out of the cell at the same rate
What is a hypertonic solution?
Solutions have in too many solutes and therefore greater water loss from cells • higher osmolarity than the cytosol of body cells • if RBC are in hypertonic solution, water molecules move out of the cell faster than they enter • cells shrink in size (crenation)
What is a hypotonic solution?
Solutions have less solutes than cells, therefore water moves into the cells • lower osmolarity than the cytosol of body cells • if RBC are in hypotonic solution water molecules move into the cell faster than they exit • cells increase in size and can burst (haemolysis)
What fluid is the most prevalent in extracellular compartments?
Sodium (Na)
What fluid is most prevalent in intracellular compartments?
Potassium (K)
Define electrolytes
A substance which forms ions in a water solution
What is the chemical equation for electrolytes in water?
NaCl —> Na+ + Cl-
What happens when you manipulate electrolyte concentration?
We can alter the movement of bodily fluids via osmosis
What are electrolytes?
A tool to control the movement of fluids between the fluid compartments
When does dehydration happen?
It occurs when water loss is greater than waiter gain, therefore is a decrease in volume and an increase in osmolarity of body fluids