Cellular Phsiology Flashcards
Normal adult water intake
2500ml water per day
Fluid balance primary intake and loss
Intake = digestive tract
Loss = kidneys, skin, exhalation
Hypernatremia & body stimulation
increased sodium (Excessive water loss)
thirst & release of anti-diuretic hormone
3 key processes to maintaining homeostasis
1) fluid balance
2) electrolyte balance
3) acid - base balance
what is an electrolyte
Molecule that conducts electricity when dissolved in water
Positive charged ion
Cation
Negative charged ion
Anion
What is a non-electrolyte
Compound that do not dissociate into ions in water e.g glucose, oxygen
Diffusion is …
passive movement of molecules or atoms from high concentration into low concentration, not requiring energy
Osmosis is …
water molecules moving through semipermeable membrane from high concentration into low concentration
What is osmotic pressure ?
water drawing, water is drawn towards a membrane that contains solutes not able to diffuse across
the higher the number of solutes the higher the strength of pulling pressure
Active transport is …
Movement of compounds against a concentration gradient requiring ATP
E.G sodium/potassium pump
Facilitated diffusion
Molecules passing though a plasma membrane from an area of high concentration to low concentration using the help of a transport molecule, requiring no energy
normal pH
7.35 - 7.45
acidosis is
pH less than 7.35 due to donation/release of hydrogen ions
alkalosis is ..
pH above 7.45 due to accepting hydrogen ions
A Buffer system is …
one or more compounds that act to resist change in pH
How do buffer systems work to change pH
Increased pH = release of hydrogen into blood
Decreased pH = removal of hydrogen from the blood
How do buffer systems work to correct pH
Increased = release hydrogen into the blood
Decreased = removal of hydrogen from the blood
What are the 3 buffer systems :
1) Bicarbonate buffer system
2) protein buffer system
3) phosphate buffer system
Equation for bicarbonate buffer system
CO2 + H2O = H2CO3 = (HCO3)- + H+
OR
Carbon dioxide + water = carbonic acid = Bicarbonate + Hydrogen
Where is protein buffer system located?
Intracellular fluid and plasma
Where does bicarbonate buffer system operate
Extracellular fluid
How does the protein buffer system work?
When pH decreases amino group takes up hydrogen ions
When pH increases carboxyl group releases hydrogen
