Agents Affecting Volume And Ion Content Of Body Fluids

Front 1

What organ is responsible for the maintenance of fluid volume and osmolality.

Back 1

the kidneys

Front 2

What are the two categories of abnormal hydration?

Back 2

1. Volume contraction: a decrease in total body water
2. Volume expansion: an increase in total body water

Front 3

What are the three types of volume contraction?

Back 3

1. isotonic contraction
2. hypertonic contraction
3. hypotonic contraction

Front 4

What is isotonic contraction?

Back 4

volume contraction in which sodium and water are lost in isotonic proportion and there is a decrease in extracellular fluid with no change in osmolality

Front 5

What causes isotonic contraction?

Back 5

vomiting, diarrhea, kidney disease, and misuse of diuretics

Front 6

What is hypertonic contraction?

Back 6

volume contraction in which loss of water exceeds loss of sodium with a reduction in extracellular fluid volume and increased osmolality.

Front 7

What causes hypertonic contraction?

Back 7

excessive sweating, osmotic diuresis, and the feeding of excessively concentrated food to infants.

Front 8

What is hypotonic contraction?

Back 8

Volume contraction in which loss of sodium exceeds loss of water and both fluid volume and osmolality of extracellular fluid are reduced.

Front 9

What causes hypotonic contraction?

Back 9

excessive loss of sodium through the kidneys due to diuretic therapy, chronic renal insufficiency, or lack of aldosterone.

Front 10

How is isotonic contraction treated?

Back 10

give fluids that are isotonic to plasma. Replace slowly to avoid pulmonary edema.

Front 11

How do you treat hypertonic contraction?

Back 11

give fluids that are hypotonic or with fluids containing no solutes at all. Could be done by drinking water, or infusion of 5% dextrose.

Front 12

How do you treat hypotonic contraction?

Back 12

For mild hyponatremia and adequate renal function infuse isotonic NaCl solution. For severe Na loss, a hypertonic solution should be used.

Front 13

What causes volume expansion?

Back 13

overdose of therapeutic fluids, heart failure, nephrotic syndrome, or cirrhosis with ascites

Front 14

How do you treat volume expansion?

Back 14

diuretics or agents used for heart failure.

Front 15

What are the most important acid-base balancing mechanisms?

Back 15

1. bicarbonate-carbonic acid buffer system
2. respiratory system
3. the kidneys

Front 16

How does the respiratory system regulate acid-base balance?

Back 16

Exhalation of CO2 reduces carbonic acid and elevates pH (reduces acidity)

Front 17

What causes respiratory alkalosis?

Back 17

hyperventilation increases CO2 loss, lowering the carbonic acid content of blood and increasing pH.

Front 18

What causes respiratory acidosis?

Back 18

hypoventilation decreases CO2 exhalation, raising plasma carbonic acid and lowering pH.

Front 19

How are respiratory alkalosis and acidosis treated?

Back 19

Alkalosis: rebreathing exhaled air or a gas containing 5% CO2

Front 20

What causes metabolic alkalosis?

Back 20

Excessive loss of gastric acid through suctioning or vomiting or by taking antacids. this increases both the pH and bicarbonate in the plasma.

Front 21

What causes metabolic acidosis?

Back 21

chronic renal failure, loss of bicarbonate during severe diarrhea, and metabolic disorders that result in overproduction of lactic acid or ketoacids. Methanol and aspirin poisoning can also cause it.

Front 22

How are metabolic alkalosis and acidosis treated?

Back 22

alkalosis: infusion of sodium chloride plus potassium chloride, promoting renal excretion of bicarbonate and normalization of plasma pH

acidosis: administer an alkalinizing salt such as sodium bicarbonate or sodium carbonate.

Front 23

What is the most abundant cellular cation? What is its concentration within the cell?

Back 23

Potassium

150mEq/L

Front 24

What regulates serum potassium levels?

Back 24

The kidneys. Aldosterone increases potassium excretion and sodium retention. extracellular pH also influences serum potassium levels

Front 25

In the presence of extracellular _______ potassium uptake by cells is _________, causing a __________ in extracellular potassium levels.

Back 25

alkalosis
enhanced
reduction

Front 26

Extracellular ___________ pormotes the ______ of potassium from cells, causing exxtracellular _____________.

Back 26

acidosis
exit
hyperkalemia

Front 27

In high doses, insulin does what to potassium?

Back 27

stimulates potassium uptake by cells, reducing serum potassium levels.

Front 28

What is the difference between hypokalemia and hyperkalemia?

Back 28

hypokalemia is a deficiency of potassium in the blood while hyperkalemia is an elevation of serum potassium.

Front 29

Hypokalemia exists when serum potassium levels fall below _____.

Back 29

3.5mEq/L

Front 30

What condition is caused by simultaneous insufficiency of potassium and chloride ions?

Back 30

hypokalemic alkalosis

Front 31

What are the symptoms of hypokalemia?

Back 31

weakness or paralysis of skeletal muscle, risk of fatal dysrhythmias, and intestinal dilation and ileus.

Front 32

Why is the preferred treatment for hypokalemia potassium chloride?

Back 32

Because chloride deficiency often accompanies potassium deficiency.

Front 33

What is the main result of hyperkalemia?

Back 33

disruption of electrical activity of the heart. Also confusion, anxiety, dyspnea, weakness or heaviness of the legs, and numbness and tingling of the hands and feet.

Front 34

At which levels does one begin to see changes in the EKG of a hyperkalemic patient?

Back 34

5-7mEq/L

Front 35

What does magnesium do in the body?

Back 35

activity of many enzymes, helped regulate neurochemical transmission and the excitability of muscle, and binding messenger RNA to ribosomes.

Front 36

What are the causes of hypomagnesemia?

Back 36

diarrhea, hemodialysis, kidney disease, prolonged intravenous feeding with magnesium-free solutions, alcoholism, diabetes and pancreatitis.

Front 37

What affect does hypomagnesemia have on the cardiac and skeletal muscles, and why?

Back 37

It causes muscle excitability to the point of tetany. Low levels of magnesium allow an increase in the release of acetylcholine at the neuromuscular junction.

Front 38

What does insufficiency of magnesium do in the CNS and kidneys?

Back 38

In the CNS, increases excitability of neurons causing disorientation, psychoses, and seizures.

In the kidneys, nephrocalcinosis resulting in renal injury.

Front 39

What causes hypermagnesemia?

Back 39

Renal insufficiency with use of magnesium-containing antacids or cathartics.