Chapter 27 1

BIOLOGY 2402 Anatomy and Physiology Lecture

Chapter 27

FLUID, ELECTROLYTES, AND ACID-BASE HOMEOSTASIS

Chapter 27 2

FLUID, ELECTROLYTES, AND ACID-BASE HOMEOSTAIS

Body fluid refers to the body water and its dissolved substances. Fluid portion averages 55-60% of total body weight in lean adults. FLUID COMPARTMENTS AND FLUID BALANCE a) Intracellular Fluid (ICF) - body fluid within cells; (ie. 2/3 of body

fluid). b) Extracellular Fluid (ECF) - includes all other body fluids outside the

cells (ie 1/3 of body fluid).

(1) Interstitial fluid, about 80% of the ECF, is found in the microscopic spaces between tissue cells.

(2) Blood plasma, about 20% of ECF, is the liquid portion of blood

within blood vessels. Selectively permeable membranes separate body fluids into distict compartments.

Fluids exist in compartments, but are in constant motion from one compartment to another;

In the healthy individual, the volume of fluid in each compartment remains relatively stable- another example of homeostasis.

Fluid balance means that the various body compartments contain the required amount of water.

Osmosis is the primary way in which water moves in and out of body compartments.

Chapter 27 3 The concentration of solutes in the fluids is therefore a major determinant of fluid balance. Electrolytes (compounds that dissociate into ions) are the most solutes in body fluids. Fluid balance, then, means water balance, but it also implies electrolyte balance. The two are inseparable. Body Water Water is the largest single constituent of the body; about 45-75% of the total body weight. Varies from person to person, sex, and age. Water proportion decreases with age. An infant has the highest amount of water per body weight - 75% of body weight. Normal adult male averages about 60% body weight. Normal adult female averages about 55% body weight. (Lose water due to more subcutaneous fat in female). (Since fat is basically water-free, lean people have a greater proportion of water to total body weight than fat people.) Fluid intake and output Intake: i Preformed Water - water derived from ingested liquids (1600 ml) and

foods (700 ml) that has been absorbed from the gastrointestinal tract.

Chapter 27 4 -Primary source of body fluid 2300 ml/day

ii Metabolic Water - water produced mainly when electrons are

accepted by oxygen during cellular respiration ; and

To a smaller extent, water produced during dehydration synthesis reaction.

Both sources amount to 200 ml/day.

*Total fluid input (preformed and metabolic) averages about 2500 ml/day

Output:

Avenues of Fluid Output

Kidney 1500 ml Evaporation 400 ml

Perspiration 100 ml Lungs 300 ml GI tract 200 ml 2500 ml/day *Under normal circumstances, fluid intake equals fluid output, so the body maintains a constant volume. (Fluid Intake = Fluid Output) Regulation of Fluid Gain Fluid gain due to formation of metabolic water is not regulated to maintain homeostasis of body water. Metabolic water volume depends mostly on the level of cellular respiration which reflects the level of demand for ATP in body cells. The main way to regulate body fluid gain is by adjusting the volume of

Chapter 27 5 preformed water intake, mainly by drinking more or less fluid. Thirst is a powerful regulator of fluid intake that operetes in the following manner 1. When water loss is greater than water gain, the result is

dehydration, which may be mild or severe. 2. Dehydration stimulates thirst in at least three ways: (a) It decreases production of saliva (b) It increases blood osmotic pressure (c) It decreases blood volume 3. When production of saliva decreases, it causes dryness of the

mucosa of the mouth and pharynx.

When blood osmotic pressure increases, it stimulates osmoreceptors in the hypothalamus.

When blood volume decreases, blood pressure drops. This change stimulate release of renin by juxtaglomerular cells of the kidneys and renin promotes the synthesis of angiotensin II.

4. A dry mouth and pharynx, stimulation of osmoreceptors in the

hypothalamus, and increased angiotensin II in the blood all stimulate the thirst center in the hypothalamus.

5. As a result, the sensation of thirst is increased 6. This normally leads to increased fluid intake, if fluids are available. 7. As a result, normal fluid volume is restored and this relieves

dehydration. The net effect of the cycle is that fluid gain balances the fluid loss. Although thirst normally leads to restoration of fluid volume after a period of time, it may not act quickly enough to prevent dehydration.

Chapter 27 6 Usually, dehydration has already occured to a slight extent before the sensation of thirst is noticed. In situations of heavy sweating or fluid loss from diarrhea or vomiting, it is wise to start replacing body fluid by drinking even before you become thirsty. Additionally, the thirst mechanism is not always reliable in young children, elderly people, or in those who are in confused mental state. Unitially, quenching of thirst results from wetting the mucosa of the mouth and pharynx, but the major inhibitor of thirst is believed to be stretching of the stomach or intestines and a decrease in osmotic pressure in fluid of the hypothalamus. Regulation of Fluid Loss 1. Under Normal Circumstances:

Three hormones regulate fluid loss:

(a) Antidiuretic hormone (ADH) - An increase in blood tonicity or a decrease in blood volume stimulates release of ADH.

ADH slow fluid loss in the urine.

(b) Aldosterone - An increase in angiotensin II (see page 864 for functions) stimulates release of aldosteron.

Aldosteron slows fluid loss in the urine.

(c) Atrial natriuretic peptide (ANP) - Increased blood volume stretches the right atrium, as more blood returns to the heart, and stimulates release of ANP.

ANP causes diuresis (increased urine flow rate).

Chapter 27 7 2. Under Abnormal Conditions:

(a) Severe dehydrated, blood pressure falls, glomerular filtration rate decreases accordingly, and less water is lost in urine.

(b) Excessive fluid in blood results in an increase of blood

pressure (hypertension), rate of glomerular filtration rises, and more water is lost in the urine.

(c) Hyperventilation increases fluid loss through loss of water

vapor by the lungs.

(d) Vomiting and diarrhea result in fluid loss from the gastrointestinal tract.

(e) Fever, heavy perspiration, and destruction of extensive

reas of the skin from burns bring about excessive water loss through the skin.

CONCENTRATION OF SOLUTIONS

*(Body fluids contain a variety of dissolved chemicals): Are grouped into two: 1) Electrolytes (ions) - are compounds with at least one ionic bond;

when dissolved in a body fluid, dissociate into positive and negative ions.

Cations - Positively charged ions. Anions - Negatively charged ions.

*Example: Most inorganic compounds - acids, bases, and salts.

*Most electrolytes are inorganic compounds, but a few are organic.

Chapter 27 8

*(Several of the Krebs Cycle Acids (e.g. citric acid and oxaloacetic acid), lactic acid (lactate), and several amino acids within proteins form ionic bonds).

*(In solution, these molecules lose an ion (often H+), and the rest of the molecule carries the opposite charge.)

*Electrolyte are so-named because they can carry an electrical current.

2) Nonelectrolytes - are compounds with covalent bonds; that is, the

atoms that compose the molecules share electrons and do not form ions when dissolved.

*Example: Most organic compound, such as glucose, urea, and creatine.

Several ways to Express the Concentration of Chemical Dissolved in Body Fluid. 1. The concentration may be expressed as the amount of solute in

solution, or percent (%).

- A 0.9% NaCl solution (0.9 g of NaCl in 100 ml of solution) is isotonic to red blood cells and is called isotonic saline.

2. The concentration can be expressed as the total number of positive

(cation) and negatives (anions), or Milliequivalents/liter (mEq/liter).

One equivalent is the positive or negative charge equal to the amount of charge in one mole of hydrogen ions (H+).

A milliequivalent is one-thousandth of an equivalent.

Chapter 27 9 *(Recall that a mole is the molecular weight of a substance in grams.)

For ions such as:

Sodium (Na+) Potassium (K+)

Bicarbonate (HCO3-)

Have a single positive or negative charge, the number of mEq/liter is equal to the number of mmol/liter.

For ions such as:

Calcium (Ca2+) Phosphate (HPO4

2-)

Have two positive or negative charges, the number of mEq/liter is twice the number of mmol/liter.

One of the forces that determine concentrations of body fluid is osmosis.

During osmosis, water moves from an area with more water molecules but fewer particles in solution (lower osmotic pressure) to an area with fewer water molecules but more particles in solution (higher Osmotic pressure).

Milliosmoles/liter (mOsm/liter) - are units that express the total particles in solution.

*A particle may be a whole molecule such as glucose or and ion such as Na+.

*Because it dissociates into at least two particles, an electrolyte molecule exerts a far greater effect on Osmosis than a Nonelectrolyte molecule.

Chapter 27 10

Nonelectrolyte : H2O C6H12O6---------------------------------------------→ C6H12O6 Glucose molecule Glucose molecule Electrolyte: H2O NaCl ------------------------------------------------→ Na+ + Cl- Sodium Chloride H2O

CaCl2------------------------------------------------→ Ca2+ + Cl- + Cl- Calcium Chloride

*Because Glucose does not dissociate when dissolved in water, a molecule of glucose contributes only one particle to the solution;

*Sodium Chloride contributes two ions, or particles;

*Calcium Chloride contributes three ions, or particles.

[Example: a) 5 mmol/liter solution of CaCl2 has an osmolarity of 15 mOsm/liter ( if the salt dissociates completely.)

b) 5 mmol/liter solution of Glucose has an osmolarity of only 5 mOsm/liter. ]

*Thus each mole of calcium chloride has three times as great an osmotic effect as each mole of glucose.

-Osmotic pressure is usually expressed in mmHg.

*Each 1 mOsm/liter exerts a pressure equal to 19.3 mm Hg.

Chapter 27 11 ELECTROLYTES IN BODY FLUIDS

The ions formed when electrolytes dissolve serve four general functions in the body: 1. Control the osmosis of water between body compartments.

(Because electrolytes are more numerous than nonelectrolytes) 2. Help maintain the acid-base balance required for normal cellular

activities. 3. Carry electrical current, which allows production of action potential

and graded potential and control secretion of some hormones and neurotransmitters.

4. Several ions are cofactors needed for optimal activity of enzymes. Concentration of Electrolytes in Body Fluids (Comparison between the concentration of electrolytes in Plasma, Interstitial fluid, and Intracellular fluid.)

- Extracellular fluid - (Plasma and Interstitial fluid)

-Intracellular fluid Differences Between Plasma and Interstitial Fluid 1. The chief difference is that Plasma contains quite a few protein

anions, where as Interstitial fluid has hardly any.

*(Since normal capillary membranes are virtually impermeable to protein, plasma proteins do not move out of blood vessels into the interstitial fluid.)

2. Plasma contains slightly more sodium ions (Na+).

Chapter 27 12 3. Plasma contains fewer Chloride ions (Cl-). 4. In other respects the two fluids are similar. Differences Between Extracellular and Intracellular Fluids 1. The most abundant cation is Na+ } In Extracellular fluid 2. The most abundant anion is Cl- 3. The most abundant cation is K+ } In Intracellular fluid 4. The most abundant anions are : proteins and phosphate (HPO42-) Functions and Regulation Sodium

Sodium (Na+) is the most abundant extracellular ion, represents about 90% of extracellular cations.

Is involved in impulse transmission, muscle contraction, and fluid and electrolyte balance.

Its level in the blood is controlled by Aldosterone, antidiruretic hormone (ADH), and atrial natriuretic peptide (ANP).

*Clinical Application Hyponatremia (low); Hypernatremia (high) Chloride Chloride ions (Cl-) are the most prevalent extracellular anion.

It assumes a role in regulating osmotic pressure and forming Hcl. Help balance the level of anions in different body fluid compartments.

Chapter 27 13 Regulates reabsorption of Na+ in distal portion of the renal tubules.

Its level is controlled by Aldosterone *Clinical Application pg. 896:

Hypochloremia and Hyperchloemia Potassium

Potassium ions (K+) is the most abundant cation in Intracellular fluid.

It is involved in maintaining fluid volume, impulse conduction, muscle contraction, and regulating pH.

Plays a role in establishing the resting membrane ptential and in the repolarization phase of action potentials in nervous and muscle tissue.

-Its level is controlled by Aldosterone. Bicarbonate Bicarbonat ions (HCO3

-) are the second most prevalent extracellular anions.

Its concentration decreases as blood flow through the systemic capillaries because it is the major buffer of H+ in plasma.

Its concentration increases as blood flows through pulmonary capillaries.

The kidneys are the main regulators of blood HCO3

- concentration. Calcium

Calcium is the most abundant mineral in the body, stored in the

Chapter 27 14 bone. About 98% of the calcium in an adult is in the skeleton (and teeth). In body fluid, is principally an extracellular cation (Ca2+).

Functions also in blood clotting, neurotransmitter release, muscle contraction, and heartbeat.

Its level is controlled by parathyroid hormone (PTH) and Calcitonin (CT).

PTH stimulates osteoclasts in bone tissue to release calcium (and phosphate) from mineral salts of bone matrix.

*Clinical Application

Hypocalcemia; Hypercalcemia Phosphate

About 85% of the phosphate in an adult is present as calcium phosphate salts, which are structural components of bone and teeth.

The remaining 15% is ionized.

Their level is controlled by PTH and CT.

*Clinical Application Hypophosphatemia; Hyperphosphatemia Magnesium

In an adult, about 54% of the total body magnisium is deposited in bone matrix as magnesium salts.

The remaining 46% occurs as Magnesium ions (Mg2+) in intracellular fluid (45%) and extracellular fluid (1%).

Functionally, Mg2+ is a cofactor for enzymes involved in the metabolism of carbohydrates and proteins and Na+/K+ ATPase (the sodium pump enzyme).

Chapter 27 15 Is also important in neuromuscular activity, impulse transmission, and myocardial functioning. Its level is controlled by Aldosterone.

*Clinical Application Hypomagnesemia; Hypermagnesemia

MOVEMENT OF BODY FLUIDS

Blood is the vehicle for transport and exchange of materials between body cells and the outside world. Nutrients in food enter the blood for distribution to tissues throughout the body. Oxygen enters the lungs and then the blood. Waste products generated by cellular metabolism diffuse from the cells that produce them into the bloodstream. Interstitial Fluid is the go-between for exchanges between intracellular fluid and blood plasma. Exchange Between Plasma and Interstitial Fluid Movement of substances between Plasma and Interstitial fluid occurs across Capillary Membranes. Substances enter and leave capillaries in three ways: 1. Vesicular Transport or Transcytosis:

Chapter 27 16

-Endocytosis - substances in blood plasma cross the capillary walls into an endothelial cells

-Exocytosis - substances exit into interstitial fluid.

2. Diffusion: substances cross down their concentration gradients

(accounts for the largest part of capillary exchange in most body tissue)

*One exception is in the brain, where the blood-brain barrier blocks diffusion of many substances, especially those that are not lipid-soluble.

3. Bulk Flow: Consists of both filtration (net movement of materials

from blood into interstitial fluid) and reabsorption ( net movement of materials from interstitial flood into blood).

a. Blood Hydrostatic Pressure (BHP) b. Interstitial Fluid Hydrostatic Pressure (IFHP) c. Blood Colloid Osmotic Pressure (BCOP) d. Interstitial Fluid Osmotic Pressure (IFOP)

Net Filtration Pressure (NFP) - is the difference between the pressure that move fluid out of plasma and the pressures that push it into plasma. [Filtration and Reabsorption] NFP = (BHP + IFOP) - (BCOP + IFHP) (35 + 1) (26 + 1) = 10 mm Hg *NFP at the Arterial End of a capillary is about 10 mm Hg. -(Fluid moves out (is filtered) from plasma into the interstitial compartment at a pressure of 10 mm Hg.) *NFP at the Venous End of a capillary is about -9mm Hg.

-(Fluid moves back in (reabsorbed) from the interstitial to plasma compartment at a pressure of -9 mm Hg)

Chapter 27 17 *Fluid not reabsorbed and any proteins that escape from capillaries pass into lymphatic capillaries. Starling's Law of the Capillaries is the state of near equilibrium at the arterial and venous ends of capillary between filtered fluid and absorbed fluid, as well as that picked up by the lymphatic system. Exchange Between Interstitial and Intracellular Fluids Because Intracellular fluid and Interstitial fluid normally have the same osmotic pressure, cells neither shrink nor swell.

- K+ is the principal cation inside cells (intracellular) - Na+ is the principal cation outside cells (interstitial)

*When a fluid imbalance between these two compartments occurs, it is usually caused by a change in the Na+ or K+

concentration.) When renal function is poor, however , a decrease in the osmotic pressure of interstitial fluid can produce two very serious results: (1) Water intoxication (2) Circulatory (hypovolemic) shock (1) Both body water and Na+ are lost during excessive sweating,

vomiting, or diarrhea. If the lost is replaced by drinking plain water, body fluids become more dilute.

(2) This dilution can cause the Na+ concentration of plasma and then of

interstitial fluid to fall below the normal range (hyponatremia). (3) When its Na+ concentration decreases, the interstitial fluid's osmotic

pressure also falls; it becomes hypotonic.

Chapter 27 18 (4) The result is net osmosis of water from the hypotonic interstitial fluid

into intracellular fluid. (5) This osmosis-driven water movement has two seriuos consequences:

(a) increase tonicity of the interstitial fluid as its water content and volume decreases.

(b) decrease the tonocity of intracellular fluid. (6) Increased tonicity of interstitial fluid causes water to move from

plasma into interstitial fluid. As water enters cells, they become hypotonic and swell, a condition called water intoxication.

(7) As water moves out of plasma, blood volume decreases, which may

lead to circulatory (hypovolemic) shock. Among the symptoms of water intoxication are convulsions, coma, and possible death.

ACID-BASE BALANCE

Hydrogen ion (H+) is a very important electrolyte in terms of the body's acid-base balance.

- Most hydrogen ions are produced as a result of the cellular metabolism of substances such as glucose, fatty acids, and amino acids; some by ingested foods.

*(One of the major challenges to homeostasis is keeping the hydrogen ion concentration at an appropriate level to maintain proper acid-base balance.) -Balance of acids and bases is maintained by controlling the H+ concentration of body fluid, particularly extracellular fluid. *The pH of the extracellular fluid remains between 7.35 and 7.45 in a healthy person.

Chapter 27 19 (If there were no mechanisms for disposal of acids, the rising concentration of H+ in body fluids would quickly lead to death.) *Homeostasis of H+concentration within a narrow pH range is essential to survival. -Depends on three major mechanisms: 1. Buffer systems - buffers act quickly to temporarily bind H+, which

removes the highly reactive, excess H+ from solution but not from the body.

2. Exhalation of Carbon dioxide - by increasing the rate and depth of

breathing, more carbon dioxide can be exhaled. This reduces the level of carbonic acid and is effective within minutes.

3. Kidney excretion - the slowest mechanism, taking hours or days, but

the only way to eliminate acids other than carbonic acid is through their passage into urine and their excretion by the kidneys.

BUFFER SYSTEMS Most Buffer Systems of the body consist of a weak acid and the anion

of that acid, which functions as a weak base.

-Prevent rapid, drastic changes in the pH of a body fluid by changing strong acids and bases into weak acids and bases.

-Works within fractions of a second.

*(Strong acid dissociates into H+ more easily than does a weak acid;)

*(Strong acids therefore lower pH (that is increase acidity) more than weak ones because strong acids contribute more H+;

*(Similarly, strong bases raise pH (that is, decrease acidity) more than weak ones because strong bases dissociate more easily into

Chapter 27 20 hydroxide ions (OH-).)

The Principal Buffer Systems of The Body Fluids are The: a. Protein buffer system. b. Carbonic acid-bicarbonate system, c. Phosphate system, A. Protein Buffer System

Protein Buffer system is the most abundant buffer in body cells and plasma.

- Protein hemoglobin inside red blood cells is an especially good buffer.

- Proteins are composed of amino acids.

-Amino acid is an organic compound that contains at least one carboxyl group (COOH) and at least one amino group (NH2).

The free carboxyl group at one end of a protein acts like an acid by releasing hydrogen ions (H+) when pH rises and can dissociate in this way:

R R NH2 C COOH → NH2 C COO- + H+

H H

*H+ is then able to react with any excess hydroxide ion (OH-) in the solution to form water.

*The free amino group at the other end of a protein can act as a base by combining with hydrogen ions when pH falls as follows:

Chapter 27 21

R R NH2 C COOH + H+ → NH3C COOH H H Thus protein can buffer both acids and bases. Besides the terminal carboxyl and amino groups, side chains that can buffer H+ are present on seven of the twenty amino acids. At blood pH (7.4) the two most important amino acid buffers are histidine and cysteine As blood flows through the systemic capillaries, carbon dioxide (CO2) passes from tissue cells into red blood cells where it combines with water (H2O) to form carboci acid (H2CO3). Once formed, H2CO3 dissociates into H+ and HCO3

-. At the same time CO2 is entering red blood cells, oxyhemoglobin (Hb.O2) is giving up its oxygen to tissue cells. Reduced hemoglobin (deoxyhemoglobin) is an excellent buffer of H+, so it picks up most of the H+. Reduced hemoglobin is usually written as Hb.H for the above reason. Equations: H2O + CO2 -----------------------→ H2CO3

carbonic acid

H2CO3 ------------------------------→ H+ + HCO3-

bicarbonate ion Hb.O2 + H+ ------------------→ Hb.H + O2 Oxyhemoblobin Reduced Oxygen (released (in RBCs) hemoglobin to tissue cells)

Chapter 27 22 B. Carbonic Acid-Bicarbonate Buffer System

Carbonic Acid-bicarbonate buffer system is based on the:

a. Bicarbonate ion (HCO3-) -- acts as a weak base.

b. Carbonic acid (H2CO3) -- acts as a weak acid.

*(Buffer system can therefore compensate for either an excess or a shortage of H+).

Examples: 1. If there is an excess of H+ (an acid condition), HCO3

- can function as a weak base and removes the excess H+ as follows: H+ + HCO3

- → H2CO3

Hydrogen Ion Bicarbonate ion Carbonic acid Weak base Weak acid

In the lungs H2CO3 dissociates into water and carbon dioxide and the

carbon dioxide is exhaled. H2CO3

→ H2O + CO2

2. If there is a shortage of H+ ions (an alkaline condition), H2CO3 can function as a weak acid and provide H+ ions as follows:

H2CO3 → H+ + HCO3

- Carbonic acid Hydrogen Ion Bicarbonate ion

(When the diet contains a large amount of protein, normal metabolism produces more acids than bases and thus tends to acidify the blood rather than make it more alkaline)

Chapter 27 23 C. Phosphate Buffer System

(Acts in essentially the same manner as the Carbonic Acid- bicarbonate buffer system.)

Components of the Phosphate Buffer System:

1. Dihydrogen phosphate ion (H2PO4

-)and 2. Monohydrogen Phosphate ions (HPO4

2-).

The dihydrogen phosphate ion acts as the weak acid and is capable of buffering strong bases such as OH-.

OH- + H2PO4

- --------------------→ H2O + HPO4

- Hydroxide ion Diydrodrogen phosphate Water Monohydrogen Phosphate

(strong acid) (weak acid) (weak base)

The monohydrogen phosphate ion acts as the weak base and is capable of buffering the H+ released by a strong acids such as hydrochloric acid (Hcl).

H+ + HPO4

- ------------------------→ H2PO4-

Hydrogen ion Monohydrogen Diydrodrogen Phosphate Phosphate (Strong acid) (Weak base) (Weak acid)

*(Since the phosphate concentration is highest in intracellular fluid, the phosphate buffer system is an important regulator of pH in the Cytosol.)

Exhalation of Carbon Dioxide (Breathing also plays a role in maintaining the pH of the body)

Chapter 27 24 An increase in the carbon dioxide (CO2) concentration in body fluids increases H+ concentration and thus lowers the pH (makes it more acidic).

-Illustrated by following reactions:

CO2 + H2O → H2CO3 → H+ + HCO3-

Carbonic acid Bicarbonate ion

*Carbonic Acid is called volatile acid since it can be eliminated by exhaling CO2.

A decrease in the CO2 concentration of body fluids raises the pH (makes it more basic).

Kidney Excretion of H+

(On a daily basis metabolic reactions produce nonvolatile or fixed acids at the rate of about 1 mEq/liter of H+ for every kilogram of body weight.) *(The normal concentration of H+ in body fluids is only 0.04 mEq/liter) *The only way to eliminate this huge fixed acid load is to excrete H+ in the urine. The kidneys also synthesize new bicarbonate ions (HCO3

-) and reabsorb bicarbonate ions that have been filtered so that this important buffer is not lost in the urine. -Renal failure can quickly cause death given their contributions to acid-base balance.

Chapter 27 25 ACID-BASE IMBALANCES

Normal blood pH range is between 7.35 (=0.045 mEq of H+/liter) and 7.45 (= 0.035 mEq of H+/liter) Concentration of H+ between 45 and 35 mEq/liter. Acidosis (or Acidemia) is a condition in which blood pH is below 7.35. Alkalosis (or Alkalemia) is a condition in which blood pH is higher than 7.45. (A change in blood pH that leads to acidosis or alkalosis can be compensated to return pH to normal.) Compensation refers to the physiological response to an acid-base imbalance that attempts to normalize arterial blood pH. Respiratory compensation if it involves the respiratory system.

Metabolic compensation if it does not involve the respiratory system.

Summary of Acidosis and Alkalosis Treatment 1. Treatment of Respiratory Acidosis is aimed at increasing the

exhalation of carbon dioxide. 2. Treatment of Metabolic Acidosis consists of intravenous solutions of

sodium bicarbonate and correcting the cause of acidosis. 3. Treatment of Respiratory Alkalosis is aimed at increasing the carbon

dioxide in the body. 4. Treatment of Metabolic Alkalosis consists of fluid therapy to replace

chloride, potassium, and other electrolyte deficiencies and correcting the cause of alkalosis.