Water, Electrolyte and pH BALANCE

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Water, Electrolyte and pHBALANCE

• You are responsible for learning the material in
  this power point.
• Along the way answer the questions and take
  notes.
• There will be a class discussion so be prepared
  to share.

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Study the picture. 1. What do you think would
be a good definition for the word balance
in regard to water, electrolyte and pH balance?
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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.

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Water balance

• Use your text, Chapter 18.
• 2. How is water intake regulated?
• 3. How is water output regulated?

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Examples of water balance

• Study the diagram on the next page.
• Carefully complete this diagram as it is likely
  to be on the test.

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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)
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• What does ADH stand for?
• 5. How does ADH work?

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Water imbalanceHypothesize 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

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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.

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Electrolyte balance

• What is aldosterone?
• 9. How does aldosterone help regulate
  electrolyte balance?

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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

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Electrolyte imbalance

• A 17 year old football player in California died
  and the coroners report stated that he died of
  electrolyte imbalance from drinking too much
  water during practice.
• 10. What happened?

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pH Balance

• The metabolic processes of the body produce
  hydrogen ions. What acid is produced in each
  situation?

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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

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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

12. Replace the symbols with words and explain
how this buffer system is working.
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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.
• Removing HCO3- from the blood helps lower the pH.

13. Why does high heart rate hinder CO2
removal?
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pH Imbalance