1. Water, Electrolyte and pH BALANCE
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Water, Electrolyte, and pH Balance Notes
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2. Study the picture What do you think would be a good definition for the word “balance” in regard to water, electrolyte and pH balance?
Balance: The amount entering equals the amount leaving.

3. Balance
Two important balance concepts: *To maintain homeostasis, the quantities of water and electrolytes must be in balance. *Because electrolytes are dissolved in the water of the body fluids, water balance and electrolyte balance are interdependent.

4. Water balance Use your text, Chapter 18.
2. How is water intake regulated?
Thirst- Osmoreceptor detect water levels
How is water output regulated?
Urine production

5. Examples of water balance
Study the diagram on the next page. Carefully complete this diagram as it is likely to be on the test.

6. Water content of the blood HIGH Water content of the blood LOW
Too much water drunk
Too much salt
or sweating
Brain produces
More ADH
Brain produces
Less ADH
Water content
of the blood normal
Low volume of water
reabsorbed by kidney
High volume of water
reabsorbed by kidney
Urine output
HIGH
Urine output
LOW
(small volume of
Concentrated urine)
(large volume of
dilute urine)

7. What does ADH stand for?
Antidiuretic hormone
How does ADH work?
ADH increases the permeability of the distal convoluted tubule and collecting duct which increases water reabsorption and reduces urine production.

8. Water imbalance Hypothesize the correct description for each condition and then check your answers.
Dehydration An abnormal accumulation of extracellular fluid in interstitial Water intoxication spaces Edema Results in a large volume of urine and concentrated blood which Use of diuretics puts pressure on brain cells Too much water results in swollen tissue causing cells to burst, may result in seizures, coma and death Water output exceed water intake resulting in dry skin , loss of body weight, and difficulty regulating temperature

9. Electrolyte balance
Below is a picture of electrolyte balance. Fill in the arrows with
Electrolyte sources for the body.
Ways in which electrolytes are lost.
Food
Perspiration
Beverages
Feces
By-product of
Metabolic reactions
Urine production

10. Electrolyte balance What is aldosterone? A hormone
How does aldosterone help regulate electrolyte balance?
Aldosterone increases sodium reabsorption, and cause tubular secretion of potassium ions.

11. Electrolyte imbalance
Hypothesize the correct description for each condition and then check your answers. Hyponatemia When the adrenal cortex does not regulate potassium levels correctly, Hypernatremia muscle weakness may occur Hypokalemia Prolonged sweating or vomiting may result in low Na and water intoxication Hyperkalemia High potassium levels may cause paralysis During high fever high sodium levels may effect the nervous system resulting in confusion

12. Electrolyte imbalance
A 17 year old football player in California died and the coroner’s report stated that he died of electrolyte imbalance from drinking too much water during practice.
What happened?
Watch this video LINK
He diluted the concentration of electrolytes already low from sweating. Water entered his cells (osmosis) and they burst

13. pH Balance
The metabolic processes of the body produce hydrogen ions. What acid is produced in each situation?
Acidic Ketone Bodies
Sulfuric acids
Phosphoric acid
Carbonic Acid
Lactid Acid

14. pH Balance
11. Hydrogen ions are regulated by: a. An acid-base buffer system b. The respiratory center in the brain stem which increases or decreases the rate of breathing c. Nephrons in the kidneys which excrete excess H+ ions So what body systems regulate pH? Respiratory, Nervous, Urinary, Cardiovascular

15. pH Balance
By far the most important buffer for maintaining acid-base balance in the blood is the carbonic-acid-bicarbonate buffer. The simultaneous equilibrium reactions of interest are H+ + HCO3 H2CO3 H2O + CO2
Hydrogen
Ions
Bicarbonate
Carbonic acid
water
Carbon dioxide
Controlled by Respiration
Kidney controlled

16. pH Balance
This figure shows the major organs that help control the blood concentrations of CO2 and HCO3- (bicarbonate), and thus help control the pH of the blood.
Removing CO2 from the blood helps increase the pH. Is CO2 an acid or base?
Removing HCO3- from the blood helps lower the pH. Is HCO3- an acid or base?
13. Why does high heart rate hinder CO2 removal?
Blood is pumped more quickly so less time for gas exchange.
Watch this video to learn about pH imbalance
LINK

17. Try to match the component of the body with the effect of pH imbalance
Enzymes Organs Microbes Oxygen Minerals
Can change shape, mutate, and become pathogenic
Can change from constructive to destructive
Delivery to cells is decreased
Can become compromised (brain, heart)
Assimilation can be thrown off