11.22 A

Question 1

The osmolality of the extracellular body fluid fraction can increase in what two ways?

Answer 1

• addition of impermable solutes

- loss of water from the extracellular fraction

Question 2

The osmolality of the extracellular body fluid fraction can decrease in what two ways?

Answer 2

• loss of impermeable solutes

- addition of water to the extracellular fraction

Question 3

How can fluid be added or lost from the extracellular body fluid fraction in an isotonic manner?

Answer 3

• loss of blood (via hemorrhage)

- infusion of saline

Question 4

An increase in ECF volume is called what?

Answer 4

an expansion

Question 5

A decrease in ECF volume is called what?

Answer 5

a contraction

Question 6

An increase in ECF volume will have what effect on the cardiovascular system?

Answer 6

• increase plasma volume
• increase venous return
• increase preload of ventricles
• increase stroke volume
• increase cardiac output
• increase MAP

Question 7

A decrease in ECF volume will have what effect on the cardiovascular system?

Answer 7

• decrease plasma volume
• decrease venous return
• decrease preload of ventricles
• decrease stroke volume
• decrease cardiac output
• decrease MAP

Question 8

What are the six types of volume and electrolyte disturbances?

Answer 8

• hypotonic expansion or contraction
• isotonic expansion or contraction
• hypertonic expansion or contraction

Question 9

Give an example of a hypotonic expansion.

Answer 9

excessive water intake

Question 10

Give an example of a hypotonic contraction.

Answer 10

salt loss (kidney)

Question 11

Give an example of an isotonic expansion.

Answer 11

IV infusion of saline

Question 12

Give an example of an isotonic contraction.

Answer 12

hemorrhage

Question 13

Give an example of a hypertonic expansion.

Answer 13

IV infusion of hypertonic saline

Question 14

Give an example of a hypertonic contraction.

Answer 14

dehydration

Question 15

What is a hypotonic contraction?

Answer 15

a volume and electrolyte disturbance that decreases ECF volume and and decreases the ECF osmolality

Question 16

IV saline will have what effects on TBW volumes?

Answer 16

ECF will increase and ICF will remain unchanged

Question 17

What would happen if you drank too much water?

Answer 17

ECF volume increases and the osmolality decreases so water flows into the ICF fraction and that increases as well

Question 18

Bleeding will result in what sort of body fluid disturbance?

Answer 18

it would be an iostonic contraction

Question 19

What happens to someone when they become dehydrated?

Answer 19

loss of ECF volume, loss of ICF volume and blood volume, which leads to diminished MAP

Question 20

Give the equation for calculating water deficit.

Answer 20

H2O deficit = present TBW x {(current[Na] / desired [Na]) - 1}

Question 21

A massive intake of sodium what increase the osmolality of what body fluid fraction?

Answer 21

the extracellular fraction

Question 22

A massive intake of sodium what have what effects on ICF and ECF volume?

Answer 22

it would increase ECF volume at the expense of ICF volume

Question 23

A kidney defect that impaired the reabsorption of sodium would have what effects on ICF and ECF volume?

Answer 23

ECF osmolality would decrease and water would move into the ICF fraction, increasing the ICF volume

Question 24

What is the most common electrolyte disorder?

Answer 24

hypovolemic hyponatremia

Question 25

What is hypovolemic hyponatremia?

Answer 25

the most common electrolyte disorder, it is characterized by a loss of sodium from the ECF

Question 26

Give the equation for calculating one’s sodium deficit.

Answer 26

Na deficit = TBW x (desired[Na] - present [Na])

Question 27

What is the role of arginine vasopressin?

Answer 27

• aka anti-diuretic hormone (ADH)
• released in response to increased body fluid osmolality
• acts to increase water reabsorption by the kidneys

Question 28

Thirst increases when what happens to body fluid?

Answer 28

the osmolality exceeds 290 mOsm

Question 29

What is the role of aldosterone?

Answer 29

a hormone that stimulates the kidney to increase sodium reabsorption in exchange for potassium

Question 30

What are the two major natriuretic peptides?

Answer 30

BNP and ANP

Question 31

What is BNP?

Answer 31

a major natriuretic peptide released from cardiac ventricles in response to champer distension
- works to increase water and sodium output by the kidney

Question 32

What is ANP?

Answer 32

• a major natriuretic peptide released from cardiac atria in response to champer distension
• works to increase water and sodium output by the kidney