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.

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?

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.

Water balance

• Use your text, Chapter 18.

2. How is water intake regulated?

3. How is water output regulated?

Examples of water balance

Study the diagram on the next page.

Carefully complete this diagram as it is likely to be on the test.

Water content of the blood normal

Water content of the blood HIGH

Water content of the blood LOW

Too much water drunk

Too much salt or sweating

Brain producesMore ADH

Urine output LOW

Brain produces Less ADH

Urine output HIGH

High volume of waterreabsorbed by kidney

Low volume of waterreabsorbed by kidney

(small volume of Concentrated urine)

(large volume of dilute urine)

4. What does ADH stand for?

5. How does ADH work?

Water imbalanceHypothesize the correct description for each condition and then

check your answers.

Dehydration An abnormal accumulation ofextracellular fluid in interstitial

Water intoxication spaces

Edema Results in a large volume of urineand 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

Electrolyte balance

Below is a picture of electrolyte balance. Fill in the arrows with6. Electrolyte sources for the body.7. Ways in which electrolytes are lost.

Electrolyte balance

8. What is aldosterone?

9. How does aldosterone help regulate electrolyte balance?

Electrolyte imbalanceHypothesize 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 mayresult in low Na and water intoxication

HyperkalemiaHigh potassium levels may cause paralysis

During high fever high sodium levels may effect the nervous system resulting in confusion

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.

10. What happened?

pH Balance

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

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

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.

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?

pH Imbalance