UNIT 8 - FLUIDS & ELECTROLYTES

Question 1

p

Answer 1

Potential

Question 1

H

Answer 1

Hydrogen

Question 1

pH ranges

Answer 1

Acidic solutions have pH below 7, basic solutions have pH above 7, neutral solutions have pH 7

Question 1

pH units

Answer 1

Each pH unit is 10 times as larger as the previous one (eg. Change of 2 pH units = 100x more acidic/basic)

Question 1

pH

Answer 1

Scale from 0-14 that specifies the acidity/basicity of a solution (measure of hydrogen ions present per litre of solution in g)

Question 2

Electrolytes

Answer 2

Compound that releases ions in water and conducts electric current and are found in all bodily fluids (eg. Cations, anions)

Question 3

Strong electrolytes

Answer 3

Compound that dissociate in water and produces positive and negative ions and conduct an electric current (eg. NaCl = Na+ Cl- (100% ions)

Question 4

Non-electrolytes

Answer 4

Compounds that dissolve as molecules in water and do not produce ions or conduct electric current

Question 5

Functions of electrolytes (4)

Answer 5

• Act a co-factors for enzymes
• Maintenance of fluid balance osmosis)
• Maintenance of acid-base balance (pH)
• Neuromuscular activity and synaptic transmission (electrical currents)

Question 6

The electrolyte trio

Answer 6

Sodium, magnesium, potassium

Question 7

Extracellular fluid

Answer 7

Body fluid outside cells

Question 8

Extracellular fluid characteristics (3)

Answer 8

• Na+ & Cl-
• Cation concentrations similar in both plasma and interstitial fluid (ions can move easily between them)
• Anion concentrations similar in both plasma and interstitial fluid, except for protein anion concentration = higher in plasma

Question 9

Sodium (Na) functions

Answer 9

Impulse transmission, muscle contraction, fluid & electrolyte balance

Question 10

Chloride (Cl) functions

Answer 10

Osmotic pressure, HCl formation in gastric acid controlled by hormones

Question 11

Intracellular fluid

Answer 11

Fluid inside cells

Question 12

Intracellular fluid characteristics (3)

Answer 12

• K+ & PO43-
• Mg2+ major cation for activating enzymes
• Larger concentration of protein anions here

Question 13

Potassium (K) function

Answer 13

Resting membrane potential, action potential for nerves/muscles, intracellular volume, pH regulation

Question 14

Acid

Answer 14

Solution with excess H+ ions, the more H+ ions then the more acidic

Question 15

Base

Answer 15

Solution with excess OH- ions, and are substances that can accept hydrogen ions

Question 16

Sources of acids in body (4)

Answer 16

• CO2 from total combustion of carbohydrates
• Metabolic processes: Breakdown of protein, glucose, fat, organic molecules
• Nitrogenous waste: uric acid
• HCl gastric acid

Question 17

Sources of bases in body (3)

Answer 17

• Bile salts
• Pancreatic juice
• Alkaline drugs

Question 18

Mechanisms by which the body regulates pH (3)

Answer 18

• First line defense: Blood buffer (bicarbonate-carbonic, phosphate, protein)
• Second line defense: Respiratory system
• Third line defense: Renal regulation (excretory)

Question 19

Blood buffer

Answer 19

Immediate, short-term mechanism for maintaining pH

Question 20

Bicarbonate-carbonic acid buffer system

Answer 20

Buffer system for maintaining pH in blood and most effective in extracellular fluid. Carbonic acid act as weak acid, and sodium bicarbonate act as weak base

Question 21

Phosphate buffer system

Answer 21

Buffer system for maintaining pH in renal tubular fluid (urine) and most effective in intracellular fluid. Phosphate ions act has weak acids and bases

Question 22

Protein buffer system

Answer 22

Buffer system for maintaining pH by proteins and most abundant in intracellular fluid & blood plasma. Carboxyl group are weak acids, amino groups are weak baes (eg. Hemoglobin)

Question 23

Respiratory system

Answer 23

: Regulates how much CO2 stays/leaves body and works within 1-3 min to affect pH

Question 24

Respiratory regulation in increase of acidity of blood (4)

Answer 24

• Results in increase of hydrogen ions
• Hydrogen ions combine with bicarbonate to form carbonic acid
• Carbonic acid forms CO2 and H2O
• Excess CO2 removed from system

Question 25

Respiratory regulation in decrease of acidity of blood (3)

Answer 25

• Results in decrease of hydrogen ions
• Lungs need to retain CO2 and form more carbonic acid
• Carbonic acid breaks down to form more hydrogen ions and bicarbonate

Question 26

Renal regulation

Answer 26

Controls acid-base balance by excreting or secreting various ions and requires hours or days to affect pH

Question 27

Acidosis

Answer 27

Condition in decrease in pH below 7.35; kidneys generate bicarbonate and add to blood to equal out the amount of hydrogen ions to urine

Question 28

Respiratory acidosis

Answer 28

Most common cause of blood pH imbalance caused by anything that interferes with CO2 leaving the blood to alveoli (eg. Emphysema, edema, damage to respiratory muscles or breathing centers in brain)

Question 29

Metabolic acidosis

Answer 29

Caused by buildup of acid metabolic products or loss of bicarbonate ions from body best indicated by low blood pH + low blood bicarbonate

Question 30

Alkalosis

Answer 30

Condition in increase in pH above 7.45; kidneys secrete bicarbonate ions and absorb hydrogen ions

Question 31

Respiratory alkalosis

Answer 31

Can be caused by hyperventilation due to loss of CO2 from stress/pain

Question 32

Causes of hyperventilation (3)

Answer 32

• High altitudes
• Anxiety
• Aspirin overdose

Question 33

Metabolic alkalosis

Answer 33

Caused by excessive loss of acids from body (vomiting) best indicated by rising blood pH and bicarbonate levels

Question 34

ROME (2)

Answer 34

• Respiratory = Opposite: pH is high PCO2 is low (alkalosis), pH is low PCO2 is up (acidosis)
• Metabolic = Equal: pH is high HCO3 is high (alkalosis, pH is low HCO3 is low (acidosis)