Physiology 1 - Fluid Compartments and Homeostasis

Question 1

What is meant by the term osmolarity?

Answer 1

The concentration of osmotically active particles within a solution

Question 2

What are the units of osmolarity for body fluids?

Answer 2

mosmol/l

Question 3

What is the osmolarity of most body fluids?

Answer 3

300mosmol/l

Question 4

What effect does an isotonic solution have on cell volume?

Answer 4

No effect

Question 5

What effect does a hypotonic solution have on cell volume?

Answer 5

Increase

Question 6

What effect does a hypertonic solution have on cell volume?

Answer 6

Decrease

Question 7

What percentage of a male’s body weight is made up of water?

Answer 7

60%

Question 8

What percentage of a female’s body weight is made up of water?

Answer 8

50%

Question 9

Why do females have less total body water than males?

Answer 9

They have more fat cells

Question 10

Which body fluid compartment makes up 67% of total body water?

Answer 10

Intracellular fluid (ICF)

Question 11

Which body fluid compartment makes up 33% of total body water?

Answer 11

Extracellular fluid (ECF)

Question 12

What are the two major components of the extracellular fluid volume?

Answer 12

Interstitial fluid and plasma

Question 13

Which component makes up 80% of the extracellular fluid volume?

Answer 13

Interstitial fluid

Question 14

Which component makes up 20% of the extracellular fluid volume?

Answer 14

Plasma

Question 15

What tracer can be used to measure total body water?

Answer 15

Tritiated water

Question 16

What tracer can be used to measure extracellular fluid volume?

Answer 16

Inulin

Question 17

What tracer can be used to measure plasma volume?

Answer 17

Labelled albumin

Question 18

What are the three main examples of sensible losses of water from the body?

Answer 18

Sweat, faeces, urine

Question 19

What is meant by the term insensible losses of water?

Answer 19

There are no regulatory mechanisms to prevent these losses

Question 20

How much water does the average person lose as urine each day?

Answer 20

1500ml

Question 21

If an individual is in hot weather or does prolonged heavy exercise, what is the only way to maintain water homeostasis?

Answer 21

Increase water ingestion

Question 22

Which ion(s) is/are found in higher concentrations in the ECF compared with the ICF?

Answer 22

Sodium, chloride, bicarbonate

Question 23

Which ion(s) is/are found in higher concentrations in the ICF compared with the ECF?

Answer 23

Potassium

Question 24

If the osmolarity of the ECF increases, what happens to the volume of the ECF and ICF?

Answer 24

ECF volume will increase, ICF volume will decrease

Question 25

If the osmolarity of the ECF decreases, what happens to the volume of the ECF and ICF?

Answer 25

ECF volume will decrease, ICF volume will increase

Question 26

Why can minor fluctuations in plasma potassium levels have detrimental consequences?

Answer 26

Potassium plays a major role in establishing the membrane potential

Question 27

What are some potential consequences of increased ECF potassium?

Answer 27

Paralysis and cardiac arrhythmias