A&P: Water, Electrolyte, & Acid-Base Balance

Question 1

Describe how water balance is related to electrolyte balance

Answer 1

• Water balance is interdependent to electrolyte balance because H2O follows salt (electrolyte)
  -> Ex: increase loss of electrolyte = increase loss of H2O

Question 2

Define: Acid-Base Balance

Answer 2

• production of H+ = loss of H+

Question 3

Name examples of extracellular fluid in the body

Answer 3

• Interstitial fluid
• Blood
• Lymph

Question 4

What mechanism maintains the electrolyte dominance of potassium ions in ICF and sodium ions in ECF?

Answer 4

• Na+/K+ pump

Question 5

What type of transport does the Na+/K+ pump use?

Answer 5

• (Primary) Active Transport

Question 6

Other than consuming moist foods and drinking beverages, how else is water “introduced” into the body?

Answer 6

• Metabolic generation (Cellular Respiration) because glucose + O2 -> CO2 + H2O + ATP

Question 7

What regulated H2O intake?

Answer 7

• controlled via Thirst center in hypothalamus

Question 8

What regulates H2O output? Provide an example

Answer 8

• controlled via DCT and CD of kidney
  -> ADH released -> ⬆H2O reabsorption -> ⬇Urine output

Question 9

Concentration of individual electrolytes affects a variety of _____ _______

Answer 9

cell functions.

Question 10

Know and be able to name important electrolytes in the body

Answer 10

• H+
• Na+
• K+
• Ca2+
• HCO3- (bicarbonate)
• Mg
• Cl- (chloride)
• SO4 2- (sulfate)
• PO4 3- (phosphate)

Question 11

Name 2 conditions that are a result of electrolyte imbalance. Name the condition and define it.

Answer 11

• Hyponatremia - low concentration of Na+ in the blood
• Hypernatremia - high concentration of Na+ in blood

Question 12

In Acid-Base balances, what would release H+? What combines with H+?

Answer 12

• Acids: release H+ (proton donor)
• Bases: combine with H+ (proton acceptor)

Question 13

pH affects all body systems, but which two body systems are really sensitive to pH changes?

Answer 13

• Nervous System
• Cardiovascular System

Question 14

What pH value do you need to be below/above for it to be considered acidosis/alkalosis?

Answer 14

• Acidosis: below 7.35
• Alkalosis: above 7.45

Question 15

Write the reaction of the bicarbonate buffer system in blood.

Answer 15

CO2 + H2O ⇋ H2CO3 ⇋ H+ + HCO3

Question 16

Based on the normal chemical reactions that occur in the body to regulate pH, what will happen to pH if a person is holding their breath?

Answer 16

⬆CO2 = ⬆H+ = ⬇pH (acidic)

Question 17

Based on normal chemical reactions that occur in the body to regulate pH, what will happen to pH if a person is hyperventilating?

Answer 17

⬇CO2 = ⬇H+ = ⬆pH (alkaline)

Question 18

Name 3 important buffer systems in the body

Answer 18

• Protein Buffer System
• Carbonic Acid-Bicarbonate Buffer System
• Phosphate Buffer System

Question 19

T/F: Buffer systems will temporarily solve the problem of acid-base imbalances

Answer 19

True

Question 20

What is the purpose of protein buffer system in the body?

Answer 20

• Regulate pH of ICF and ECF by accepting/donating H+ to amino acids amine (NH2)/carboxyl group (COOH)

Question 21

What is the purpose of carbonic acid-bicarbonate buffer system in the body?

Answer 21

Bicarb acts as weak base (accept H+) and Carbonic Acid acts as weak acid (donate H+)

Question 22

What is the purpose of phosphate buffer system in the body

Answer 22

Regulates pH of ECF and ICF (more important to ICF) via H2PO4- (anion, weak acid) to combine/donate H+

Question 23

What buffer system is MOST important to maintaining balance in ICF?

Answer 23

• Phosphate Buffer System

Question 24

What part of the brain acts as the respiratory system?

Answer 24

Brainstem (medulla oblongata) regulates H+ ions by adjusting rate and depth of breathing

Question 25

Describe Respiratory compensation and how this happens

Answer 25

• Change in respiratory system.
  -> CO2 sensed by chemoreceptors in carotid/aortic bodies to signal CNS

Question 26

Describe renal compensation

Answer 26

changes in rates of H+ and Bicarbonate ion secretion/absorption in kidney

Question 27

Describe Respiratory Acidosis
Include: What is it caused by and how it leads to acidosis

Answer 27

• Caused by the inability to eliminate CO2, usually because of hypoventilation or abnormally low respiration rate
• Leads to acidosis because: If ⬆CO2 = ⬆H+ = ⬇pH (acidic)

Question 28

Describe Respiratory Alkalosis
Include: What is it caused by and how it leads to alkalosis

Answer 28

• Caused by increased respiratory activity that causes drop in CO2, usually because of hyperventilation
• Leads to alkalosis because: If ⬇CO2 = ⬇H+ = ⬆pH (alkaline)

Question 29

Describe Metabolic Acidosis
Include: What is it caused by and have an understanding of how it leads to acidosis

Answer 29

• Caused by large production of metabolic acids
• Ex: Lactic acid (anaerobic CR)
  ketone bodies (fat breakdown)
  kidneys not eliminated H+ (⬆H+ in body = ⬇pH)
  loss of bases (nothing to combine with H+ -> ⬆H+ = ⬇pH)

Question 30

Describe: Metabolic alkalosis

Include: What it is caused by and be able to describe how this will leads to alkalosis

Answer 30

• Caused when bicarbonate ions becomes elevated, which reduces H+ ions
• ⬆Bicarbonate = combines with lots of H+ = ⬇H+ = ⬆pH (alkaline)

Question 31

If the blood becomes too acidic (low pH), the respiratory system ___ the breathing rate to ___ more CO₂, which ___ acidity.

Answer 31

increases
expel
reduces

Question 32

If the blood becomes too alkaline (high pH), the respiratory system ____ the breathing rate to ___ CO₂, which ___ acidity.

Answer 32

decreases
retain
increases