Fluid And Acid Base Balance

Front 1

How do humans and animals gain electrolytes within the body system?

Back 1

Electrolytic gain is achieved through dietary means. Electrolytes are found in the foods and drinks that we consume each day.

Front 2

Daily gains must always must always balance the daily losses. True/False

Back 2

True. If 400 mg of Na+ is lost through urine and insensible losses(sweating), it must be replaced by 400 mg of Na+ through the diet.

Front 3

When is an individual considered in acid-base balance?

Back 3

Acid base balance is achieved when the production of hydrogen ions in the body is offset by its loss.

Front 4

Regarding the total body weight of water, at least 2/3 of this weight can be found in the ECF(extra cellular fluid). True/False

Back 4

False. In fact, 2/3 of total body water is in ICF, and 1/3 exists in the ECF.

Front 5

What are the three major ions found in the ECF?

Back 5

Sodium, chloride and bicarbonate.
ICF- potassium, magnesium, phosphate ions and many negatively charged proteins.

Front 6

How might receptors accurately monitor fluid or electrolyte balance?

Back 6

Technically and physiologically they do not. They can measure and sense fluid volume(plasma) and osmotic concentration.
Receptors cannot assess specifically how many grams we gain or lose through the course of a day.

Front 7

Can it be said that water always follows salt?

Back 7

Yes. When sodium crosses epithelial walls, Water will follow ions being actively transported across cell membranes.

Front 8

What are three important hormones for fluid and electrolyte balance?

Back 8

ADH
Aldosterone
Natriuretic peptides(ANP and BNP)

Front 9

Which cells in the hypothalamus can monitor the osmotic concentration of the ECF?

Back 9

Osmoreceptors.
Roughly, a 2% change in osmotic concentration(5-6mOsm/L) will change osmoreceptor activity.

Front 10

State three reasons why renin would be released.

Back 10

1. Drop in plasma volume or blood pressure.
2. Falling sodium concentration, or increases in K+
3. A decline in filtrate osmotic concentration at the DCT(distal convoluted tubule)

Front 11

What might trigger a release of the natriuretic peptides (ANP and BNP).

Back 11

These substances are release by cardiac cells in response to sensing an abnormal stretching of the cardiac walls. This is usually due to hypertension, regardless of its cause.

Front 12

Can water move back and forth across mesothelial surfaces?

Back 12

Yes. These surfaces line the peritoneal, pleural and pericardial cavities.
Approximately, 6-7 liters of peritoneal fluid are produced and then reabsorbed each day.

Front 13

Regarding the exchange between plasma and interstitial fluid, how is this exchange physiologically determined?(Think physiological forces)

Back 13

This exchange occurs due to the net hydrostatic pressure(NHP-pushes water out of plasma) and the net colloid osmotic pressure(NCOP-tends to draw water out of the interstitial fluid and back into the plasma).

Front 14

Approximately how much water is lost throughout the course of a normal day?

Back 14

About 2.5 liters. This is lost through urine, feces and perspiration. Any increase in body movement that results in increased core temperature, will cause this number to rise significantly.

Front 15

If the osmotic concentration of the ECF increases, what affect will this have on the ICF?

Back 15

If osmotic concentration increases, this fluid becomes hypertonic(gain in solutes) and the ICF in comparison becomes hypotonic. Water will move from the cells into the ECF. Ex. RBCs would shrink or crenate.

Front 16

In treating acute dehydration, why are hypotonic fluids usually administered?

Back 16

Hypotonic fluids will quickly increase ECF volume by shifting water back into the ICF.

Front 17

In overhydration, which ion is noted to be particularly low in the plasma?

Back 17

Sodium ion concentrations are very low in overhydration. (hyponatrmia). The low sodium levels results in a fluid shift into the ICF.

Front 18

What might be a logical therapeutic protocol for overhydration?

Back 18

In such severe cases, diuretics and salt solution infusions.
Salt infusions encourage a water shift from the ICF to the ECF.

Front 19

Which two cations are considered major contributors to ECF and ICF osmotic concentration?

Back 19

Sodium and potassium. These cations are largely responsible for the normal functioning of all cells.
Sodium is the dominant cation in the ECF.

Front 20

What is the normal concentration of sodium in ECF?

Back 20

130-140 mEq/L.
The ICF is roughly 10mEq/L

Front 21

Which is the major cation in the ICF?

Back 21

Potassium is the major cation in the ICF.
Normal values are assessed at about 160mEq/L.

Front 22

Aldosterone secretion is triggered by which substance regarding blood volume regulation?

Back 22

Angiotensin 11.

Aldosterone conserves sodium. It tends to excrete potassium.

Front 23

In strenuous enduring exercise, high sugar supplement concentrations >10g/dl, in drinks may trigger muscle cramping. True/False

Back 23

True. Those that imbibe foods or drinks with just less than 10g/dl may perform better if these products are consumed late in the event when metabolic reserves tend to be low.

Front 24

What is the most abundant mineral in the body?

Back 24

Calcium. On average , an individual may have between 1-2,000 grams of calcium. Almost 100% of it is stored in the bones.

Front 25

What are some functions of calcium in the body?

Back 25

Calcium is vital for both nerve and muscle function. It is important in blood clotting, enzymatic reactions and as cellular second messengers.

Front 26

What are the functions of parathyroid hormone and calcitriol?

Back 26

These substances raise blood calcium.
Calcitonin has an antagonistic effect.

Front 27

At what point is hypercalcemia generally diagnosed?

Back 27

This condition exists when calcium concentration levels in the ECF exceed 5.5mEq/L.
Hyperparathyroidism is usually considered a major cause.
An exaggerated secretion of PTH is the source.

Front 28

Are there other causes of hyperparathyroidism?

Back 28

Yes. Some cancers such as lymphomas, and possibly other malignancies of the lung, the breast, the kidney and bone marrow have been responsible for hypercalcemia.
Overdosing of vitamin D(rare) and calcium supplementation may play a role as well.

Front 29

Is hypocalcemia a common condition?

Back 29

No. Blood concentrations less than 4.5mEq/L may signal hypocalcemia.
Hypoparathyroidism, vitamin D deficiency, and chronic renal failure may result in hypoparathyroidism.

Front 30

What are considered some typical signs and symptoms of hypoparathyroidism?

Back 30

Cardiac effects such as weak heartbeats, arrhythmias, muscle spasms, cramping and osteoporosis when confirmed via dexa scans.

Front 31

Approximately how much magnesium is found in the body?

Back 31

The body has on average close to 30 grams of magnesium. between 60-65% of it is found in the skeleton.

magnesium is important for enzymatic reactions, the phosphorylation of glucose and the use of ATP for muscle fiber contraction.

Front 32

The presence of phosphate ions is necessary for the mineralization of bone. True/False

Back 32

True. About 750 grams of PO4(-3) is bound in mineral salts within the skeleton.

Front 33

What is the phosphate concentration in the plasma?

Back 33

Phosphate concentration in the plasma is between 1.9-2.9mEq/L.
PO4 ion reabsorption takes place in the proximal convoluted tubule in the kidney.

Front 34

How are chloride ions reabsorbed?

Back 34

Chloride ion reabsorption takes place across the digestive tract along with sodium ions. It also occurs within the renal tubules.

Front 35

Alterationb of body pH can be altered by the administration of acids or bases. True/False

Back 35

True. Strong acids and bases dissociate completely in solution.
Ex. HCl acid dissociates into hydrogen and Cl- ions.

Front 36

Define pH.

Back 36

Potential of hydrogen. pH represents the negative exponent(negative) logorithm) of hydrogen ion concentration.
pH scale is measured from 1-14. 1 is most acidic and 14, is most basic.

Front 37

What is an acid?

Back 37

Acids are substances that dissociate to release hydrogen ions, which will decrease pH.
Bases are substances that dissociate to release hydroxide ions, or that can bind hydrogen ions. Bases increase pH.

Front 38

When is acidemia said to exist?

Back 38

When blood plasma falls below 7.35. Acidosis is the result.
Alkalosis exists when plasma pH is above 7.45.

Front 39

What might occur with a pH below 7?

Back 39

Such a drop in bodily pH is usually fatal. There is a severe deterioration of the CNS. Cardiac contractions become weak and inefficient, and this produces a severe vasodilation critically lowering blood pressure and causing circulatory collapse.

Front 40

What are the three categorical types of acids found in the body?

Back 40

Volatile acids
Fixed acids
Organic acids

Front 41

What is a volatile acid?

Back 41

Volatile acids can leave solutions and enter the atmosphere.
Carbonic acid(H2CO3) is considered a volatile acid. Within the lungs, it breaks down into CO2 and H2O.

Front 42

Can fixed acids leave solution as well?

Back 42

No. Once they are produced, they tend to stay in body fluids until they are eliminated through the kidneys.
Sulfuric and phosphoric acids are 2 important fixed acids.

Front 43

What is an organic acid?

Back 43

These acids are generally by product acids of aerobic metabolism.
Lactic acid, which is a product of anerobic metabolism of pyruvate and ketone bodies, synthesized from acetyl CoA.

Front 44

Briefly describe the hemoglobin buffer system.

Back 44

RBCs have approximately 5-6% of the ICF. They are densely packed with hemoglobin. RBCs can significantly impact pH of the ECF. They can absorb CO2 from the plasma and convert it to carbonic acid.

Front 45

What is a fundamental role of the carbonic acid bicarbonate buffer system?

Back 45

This system is employed to prevent changes in body pH caused by organic acids and fixed acids in the ECF.

Front 46

Can the respiratory rate affect pH?

Back 46

Yes. Decreasing or increasing the rate of respiration changes the pH by the raising or lowering the PCO2.
When the PCO2 rises, the pH tends to fall, because the addition of CO2 drives the carbonic acid bicarbonate buffer system to the right.

Front 47

Chemoreceptors of the carotid and aortic bodies are sensitive to what kind of stimuli?

Back 47

These receptors are sensitive to the PCO2 of the blood.
Other chemoreceptors that monitor the PCO2 of the CSF are located in the medulla oblongata.

Front 48

In states of acidosis can the kidneys assist the lungs for pH regulation?

Back 48

Yes. The kidneys assist the lungs by getting rid of any CO2 that enters the renal tubules during filtration or diffuses into the tubular fluid as it is traveling toward the renal pelvis.
Hydrogen ions may be secreted as well into the tubular fluid along the PCT, the DCT and the collecting ducts.

Front 49

How does the body form and get rid of ammonia?

Back 49

Ammonia is produced in the tubules. Glutaminase is used for the breakdown of glutamine. as a result of this, amino acids are released as either ammonium(NH4+) or ammonia(NH3). Ammonia is considered volatile and toxic to body cells. It diffuses quickly into tubular fluid. here, it will react with a hydrogen forming NH4+. This recation will buffer the tubular fluid and removes a potentially dangerous compound from body fluids.

Front 50

How does respiratory acidosis develop?

Back 50

Respiratory acidosis develops when the respitaory apparatus cannot eliminate all the CO2 formed by peripheral cells.
Low respiratory rates result in hypocapnia.

Front 51

Can a temporary hypocapnia cause hyperventilation?

Back 51

Yes. This is the case when increased respiratory activity leads to a reduction in the arterial PCO2.

Front 52

What are some causes of hyperventilation?

Back 52

Extreme physical activity, and stresses, pain and anxiety.
In some severe cases, individuals will lose consciousness.

Front 53

Why is breathing into a paper bag sometimes recommended for hyperventilatory patients?

Back 53

As CO2 levels build up in the bag, the person re inhales the CO2. arterial CO2 levels and alveolar concentrations will rise resetting normal PCO2 levels.

Front 54

What causes lactic acidosis?

Back 54

Lactic acidosis may occur as a result of strenuous exercise or from prolonged tissue hypoxia, as active cells must rely on anaerobic respiration.

Front 55

What causes ketoacidosis?

Back 55

This results from the formation of higher than normal ketone bodies especially during the postabsorptive state of metabolism. It is seen in poorly regulated diabetics and those attempting intentional starvation.
The three endogenous ketone bodies are acetone, acetoacetic acid, and beta-hydroxybutyric acid,

Front 56

When does metabolic acidosis occur?

Back 56

This condition exists when HCO3 concentrations become abnormally elevated.
The bicarbonate ions react with hydrogen ions in solution, forming carbonic acid(H2CO3).

Front 57

What causes metabolic alkalosis?

Back 57

This is a rare disorder. Also referred to as alkaline tide syndrome, it is produced by the influx into the ECF of large numbers of bicarbonate ions.
In cases of severe or repeated vomiting, there is a considerable loss of HCl from the gastric compartment.

Front 58

What is a routine treatment for metabolic alkalosis?

Back 58

Aside from suppoertive treatment, the administration of ammonium chloride(NH4Cl).
Because of the metabolism of the ammonium ion in the liver, hydrogen ions are released from the compound. This encourages a hasty reformation of HCl in the stomach.