9th lecture - fluid and electrolyte balance substances Flashcards
The circulation of water in the organism is centrally controlled by the
thirst centre located in the hypothalamus. Osmoreceptors are in the hypothalamus as well.
The 24-hour fluid intake requirement of an organism is
40/55-132 ml/kg per day.
This depends on the animal species, gender, age and physiological condition.
An adult dog will require how many ml/kg per day?
40-60 ml/kg per day whereas a young, as well as lactating animal will have a requirement 2x higher.
The water content of the organism depends on the following (2)
Fat tissue content (The more fat tissue there is, the less water.)
Age (young animals have much greater levels)
Total water content of an,
adult animal?
young animal?
old animal?
adult animal contains 55-60% of water (as a percentage of body weight),
young animals contain 70-75% of water,
old animals contain 50%.
In the case of humans: women have 50% water, men have 60%.
Water content of different tissues,
muscle tissue
skeleton
blood
Muscle tissue contains 50% of the organism’s water content.
The skeleton contains 14%.
Blood contains 5%.
Distribution of water content in fluid compartments.
(If total water content from body weight is approx. 60%)
Intracellular: 40% of body weight
Extracellular: 20% of body weight
Extracellular fluid makes up what percentage of body weight.
20%
Blood account for what percentage of body weight?
5-8%
Interstitial fluid makes up what percentage of body weight?
14%
Fluid that is surrounding tissue cells.
The electrolyte content is insignificant.
It acts as a buffer system for volume.
Transcellular fluid makes up what percentage of body weight?
2-3% of body weight
The fluid contained within the cavities of the organism (pleural cavity, gastrointestinal tract, peritoneal cavity and others).
Ruminants have a voluminous gastrointestinal tract with up to 15% of transcellular fluid, monogastrics 1-6%.
Skin accounts for up to what % of body weight?
16% of body weight, containing up to 70% of water (of its own weight).
Water reservoir, storage of Na and Cl ions.
The flow of water between biological fluid compartments is regulated by
the colloid osmotic pressure present in the fluid compartment.
Electrolytes are
An electrolyte is a substance that dissociates in water into charged particles called ions.
Ions are electrically charged particles that start to move as a result of electrolyte dissociation in a water environment.
Name the Primary cations of an organism (4)
Sodium, Na+
Potassium, K+
Calcium, Ca2+
Magnesium, Mg2+
Name the Primary anions of an organism (4)
Chlorine, Cl-
Bicarbonate, HCO3-
Phosphate, PO4 3-
Sulfate, SO4 2-
define milliequivalent
a unit of measure, applied to electrolytes, that expresses the combining power of a substance.
abbreviation mEq.
1 mEq is the amount of a substance that will react with 1 mg of hydrogen ions.
Extracellular electrolytes: (3)
Na, Cl, bicarbonate
Intracellular electrolytes (3)
K, Mg, phosphate.
Functions of electrolytes: (7)
Ensuring the osmolarity of body fluids
Forming bioelectric membrane potentials
Act as the catalysts of metabolism
Determine the pH of bodily fluids
Stabilise tissue
Form energy depots
Participation in blood coagulation
Total sodium content in e.g.
a 500 kg cow
a 70 kg human
500 kg cow 700-800 g Na
70 kg human 100g Na
Function of sodium as a biological electrolyte
Ensures the osmolarity of the extracellular compartment.
Impacts the volume of the ICF depending upon the concentration of sodium in plasma.
When the osmolarity of plasma increases, the water will diffuse from the ICF to the ECF. The cells undergo crenation. When the osmolarity of plasma decreases, water flows back into the ICF that have higher osmolarity.
Participation in the formation of bioelectric potential of the membrane.
Total potassium conent in e.g.
a 500 kg cow
a 70 kg human
500 kg cow 900-1000 g K.
70 kg human contains 150 g K
Function of potassium as a biological electrolyte. (5)
Participation in the utilisation of carbohydrates.
Necessary for the synthesis of proteins.
Participates in the nerve-muscle stimulus transmission.
Participates in the activity of muscle, heart, central nervous system and kidney cells.
The administration of a large amount of Na will increase the excretion of K through the kidneys.
Total calcium conent in e.g.
a 500 kg cow
a 70 kg human
500 kg cow 6500-8500g Ca
70 kg human 1000-1500g Ca
99% in bones and teeth
Function of calcium as a biological electrolyte (4)
Structural element in the composition of bones and teeth.
Impacts the stimulation of muscles and nerves.
Impacts the permeability of membranes.
Participation in blood coagulation as a coagulation factor.
Total magnesium content in e.g.
a 500 kg cow
a 70 kg human
500kg cow 200-300 g Mg
70 kg human 20-28g Mg
Function of magnesium as a biological electrolyte (6)
Participation in fermentation processes
Cell regeneration
Utilisation of oxygen
Glycolysis
Suppresses nerve signal transmission (curare-like effect)
Dilates blood vessels, facilitates fibrinolysis.
Total chlorine content in e.g.
a 70 kg human
70 kg human contains 100g Cl
Function of chlorine as a biological electrolyte (2)
Primary plasma anion
Participates in the formation of membrane potential.
Bicarbonate main function
Acts as a buffer system
Balances changes in anion content
Total phosphate content in e.g.
a 70 kg human
500-800g phosphate
Function of phosphate as a biological electrolyte (3)
Makes up the bone structure together with calcium
Participates in carbohydrate metabolism
Participates in the phosphate buffer system
