9th lecture - fluid and electrolyte balance substances

Question 1

The circulation of water in the organism is centrally controlled by the

Answer 1

thirst centre located in the hypothalamus. Osmoreceptors are in the hypothalamus as well.

Question 2

The 24-hour fluid intake requirement of an organism is

Answer 2

40/55-132 ml/kg per day.

This depends on the animal species, gender, age and physiological condition.

Question 3

An adult dog will require how many ml/kg per day?

Answer 3

40-60 ml/kg per day whereas a young, as well as lactating animal will have a requirement 2x higher.

Question 4

The water content of the organism depends on the following (2)

Answer 4

Fat tissue content (The more fat tissue there is, the less water.)
Age (young animals have much greater levels)

Question 5

Total water content of an,
adult animal?
young animal?
old animal?

Answer 5

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%.

Question 6

Water content of different tissues,
muscle tissue
skeleton
blood

Answer 6

Muscle tissue contains 50% of the organism’s water content.

The skeleton contains 14%.

Blood contains 5%.

Question 7

Distribution of water content in fluid compartments.

Answer 7

(If total water content from body weight is approx. 60%)

Intracellular: 40% of body weight
Extracellular: 20% of body weight

Question 8

Extracellular fluid makes up what percentage of body weight.

Answer 8

20%

Question 9

Blood account for what percentage of body weight?

Answer 9

5-8%

Question 10

Interstitial fluid makes up what percentage of body weight?

Answer 10

14%

Fluid that is surrounding tissue cells.
The electrolyte content is insignificant.
It acts as a buffer system for volume.

Question 11

Transcellular fluid makes up what percentage of body weight?

Answer 11

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%.

Question 12

Skin accounts for up to what % of body weight?

Answer 12

16% of body weight, containing up to 70% of water (of its own weight).

Water reservoir, storage of Na and Cl ions.

Question 13

The flow of water between biological fluid compartments is regulated by

Answer 13

the colloid osmotic pressure present in the fluid compartment.

Question 14

Electrolytes are

Answer 14

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.

Question 15

Name the Primary cations of an organism (4)

Answer 15

Sodium, Na+
Potassium, K+
Calcium, Ca2+
Magnesium, Mg2+

Question 16

Name the Primary anions of an organism (4)

Answer 16

Chlorine, Cl-
Bicarbonate, HCO3-
Phosphate, PO4 3-
Sulfate, SO4 2-

Question 17

define milliequivalent

Answer 17

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.

Question 18

Extracellular electrolytes: (3)

Answer 18

Na, Cl, bicarbonate

Question 19

Intracellular electrolytes (3)

Answer 19

K, Mg, phosphate.

Question 20

Functions of electrolytes: (7)

Answer 20

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

Question 21

Total sodium content in e.g.
a 500 kg cow
a 70 kg human

Answer 21

500 kg cow 700-800 g Na
70 kg human 100g Na

Question 22

Function of sodium as a biological electrolyte

Answer 22

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.

Question 23

Total potassium conent in e.g.
a 500 kg cow
a 70 kg human

Answer 23

500 kg cow 900-1000 g K.
70 kg human contains 150 g K

Question 24

Function of potassium as a biological electrolyte. (5)

Answer 24

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.

Question 25

Total calcium conent in e.g.
a 500 kg cow
a 70 kg human

Answer 25

500 kg cow 6500-8500g Ca
70 kg human 1000-1500g Ca

99% in bones and teeth

Question 26

Function of calcium as a biological electrolyte (4)

Answer 26

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.

Question 27

Total magnesium content in e.g.
a 500 kg cow
a 70 kg human

Answer 27

500kg cow 200-300 g Mg
70 kg human 20-28g Mg

Question 28

Function of magnesium as a biological electrolyte (6)

Answer 28

Participation in fermentation processes
Cell regeneration
Utilisation of oxygen
Glycolysis
Suppresses nerve signal transmission (curare-like effect)
Dilates blood vessels, facilitates fibrinolysis.

Question 29

Total chlorine content in e.g.
a 70 kg human

Answer 29

70 kg human contains 100g Cl

Question 30

Function of chlorine as a biological electrolyte (2)

Answer 30

Primary plasma anion

Participates in the formation of membrane potential.

Question 31

Bicarbonate main function

Answer 31

Acts as a buffer system

Balances changes in anion content

Question 32

Total phosphate content in e.g.
a 70 kg human

Answer 32

500-800g phosphate

Question 33

Function of phosphate as a biological electrolyte (3)

Answer 33

Makes up the bone structure together with calcium

Participates in carbohydrate metabolism

Participates in the phosphate buffer system