Body Fluids 1

Question 1

X =

Answer 1

Question 2

Physiology is the study of how ___ works, from ___ to ___, ___ to ___, ___ to ___

and how the organism as a whole accomplishes ____

Answer 2

Physiology is the study of biologyical function

How the human body works, from cell to tissue, tissue to organ, organ to system

how the organism as a whole accomplishes particular tasks essential for life

Question 3

when talking about homeostasis in this class, we are usually referring to homeostasis of what?

Answer 3

homeostasis of the internal enviornment (however, can be of any particular enviorment)

Question 4

What makes up the internal enviornment?

Answer 4

the internal enviorment is:

• the environment our body cells are living in - the extracellular fluid (ECF), an aqueous solution (outside the cell)
• includes:
  
  • insterstitial/intercellular fluid (blue) (= fluid between the cells)
  • plasma (red) (fluid within blood vessels)

(fluid inside the cell = intracellular fluid)

Question 5

parameters of equilibrium of the ECF

Answer 5

• temperature
• blood pressure
• osmolarity
• pH, Po2, Pco2
• blood glucose, cholesterol
• Ions

(homeostasis of internal environment in a human requires homeostasis of all of these various parameters)

Question 6

A normal healthy human life requires stability in both ___ and ___

Answer 6

A normal healthy human life requires stability in both the human external environment (earth environment) and the human internal environment (ECF)..

Question 7

Damage of the equilibrium of ECF can lead to:

Answer 7

• Fever
• Hyper or hypotension
• Dehydration
• Acidosis or alkalosis
• Hyper or hypoglycemia
• Hyper or hypokalemia

Ultimately leads to diseases: pathophysiological or pathological conditions resulting from the failure of homeostasis

Question 8

The homeostasis of a particular parameter x means that x is in ___

Answer 8

•The homeostasis of a particular parameter x is that x is in its dynamic equilibrium (the fluctuation of its value is within its normal physiological range).

Question 9

2 ways body maintains homeostasis of body temperature:

Answer 9

• vasoconstriction: if temperature is too low, blood vessels constrict = you shiver = produces heat
• vasodilation: if temperature too high, blood vessels dilate = you sweat = decreased temperature (because you release heat)

this is an example of negative control loop that helps maintain parameters

Question 10

what is the principal mechanism underlying all homeostasis processes?

Answer 10

Negative feedback is the principal mechanism underlying all homeostasis processes.

The detailed process of maintaining the homeostasis of each physiological parameter can be quite different and very complicated. However, all aim to correct the parameter’s deviation from its set point.

All negative feedback systems or loops require a sensor or a sensor system, a control center or control system, and an effector or effector system.

The homeostasis of body temperature embodies the same principle of negative feedback control, but the concrete details are much more complicated.

Question 11

3 parts of negative feedback (and what they each do)

Answer 11

1) sensor: detects changes in body’s parameters
2) control center: integrates/processes input signals (if too high/too low, issue command)
3) effector: carry out output signal to correct deviations from set point

Question 12

simple definition of homeostasis in current textbooks

Answer 12

Homeostasis originally refers to the steady state (dynamic equilibrium) of the internal environment of an organism.

Question 13

• The homeostasis of a parameter is the X
• The value of X ____

Answer 13

•The homeostasis of a parameter is the dynamic equilibrium of the parameter: The value of the parameter fluctuates around its set point within its normal range.

Question 14

If the fluctuation of a parameter is beyond its normal range, then what occurs?

Answer 14

•If the fluctuation of a parameter is beyond its normal range, it is a pathophysiological situation.

A failure to maintain the homeostasis of a parameter leads to the failure of the homeostasis in the internal environment, which is what an illness or disease means from the perspective of physiology.

Question 15

The total body water (TBW) is what percent of total body weight?

Answer 15

The total body water (TBW) is about 50% to 70% of total body weight (average 60%)

Question 16

Total body water is distributed mainly between what 2 compartments:

• these compartments are what percent of body weight?
• these compartments are what fraction of total body water?

Answer 16

Total body water is made of up two compartments:

• intacellular fluid
  
  • 40% of body weight
  • 2/3 of total body water
• extracellular fluid
  
  • 20% of body weight
  • 1/3 of total body water

Question 17

The extracellular fluid (ECF) is divided into 2 subgroups:

• each subgroup is what percent of body weight
• each subgroup is what fraction of ECF?

Answer 17

The extracellular fluid (ECF) is divided into 2 subgroups:

1) Interstitial fluid (ISF)

• 15% body weight
• 3/4 ECF

2) Plasma

• 5% of body weight
• 1/4 of ECF

Question 18

Total blood volume (TBV) accounts for what percent of body weight? what is the density?

Answer 18

Total blood volume accounts for 7-8% of body weight

with an average density of approximately 1060 kg/m3; this is very close to pure water’s density of 1000 kg/m3.

Question 19

ICF:

40% of ___

2/3 of ___

Answer 19

40 % of body weight

2/3 of total body water

Question 20

ECF =

20 % of ___

1/3 of ___

Answer 20

ECF is

20% of body weight

1/3 of total body water

Question 21

ISF =

15% of ___

3/4 of ___

Answer 21

ISF is

15% of body weight

3/4 of ECF

Question 22

Plasma is

5% of ___

1/4 of ___

Answer 22

Plasma is

5% of body weight

1/4 of ECF

Question 23

what are 3 components of blood (and each of their volume percent)

Answer 23

1) plasma = 55% of whole blood
2) buffy coat: leukocytes (WBC) and platelets = < 1% of whole blood
3) erythrocytes/hematocrit/RBC = 45% of whole blood

*buffy coat and erythrocytes = formed elements

*these are volume percentages (not weight percentages)

Question 24

what is hematocrit (Htc)

Answer 24

The volume percentage (vol%) of the formed elements (mainly RBCs) in blood.

Question 25

2. What is the normal value of hematocrit for men and women?

Answer 25

~45% for men ~40% for women

Question 26

The average adult has a blood volume of \_\_\_, which is composed of \_\_\_

Answer 26

The average adult has a blood volume of roughly 5 liters, which is composed of plasma and several kinds of cells.

Question 27

All fluids inside all body cells are collectively called

Answer 27

All fluids inside all body cells are collectively called **ICF (intracellular fluid)** * The fluid of each cell contains individual mixtures of different constituents, but the concentrations of these substances are similar from one cell to another. * In fact, the composition of cell fluids is remarkably similar even in different animals, ranging from the most primitive microorganisms to humans. * For this reason, the ICF of all the different cells together is considered to be one large fluid compartment.

Question 28

All fluids outside of the cells are collectively called

Answer 28

All the fluids outside the cells are collectively called **ECF (extracellular fluid),** includes: - the ISF (interstitial/intercelluar fluid) that surrounds cells and the plasma circulating inside the vasculature = mainly a solution of salts; - the ECF inside the vasculature (plasma) = contains not only a salt solution, but also a variety of proteins as well as various blood cells

Question 29

what is transcellular fluid? - what it is made of - what amount in L? - what % body weight? - how different from ECF - how it changes with pathological conditions?

Answer 29

**an additional subcompartment of the ECF (besides the bulk compartments = ISF and plasma)** * about 1 L in total in most humans and makes up about 1.5% of body weight. * It includes fluid in the synovial, peritoneal, pericardial, and intraocular spaces, as well as the cerebrospinal fluid. * Unlike the bulk of ECF, each transcellular fluid has a distinct ionic composition. * Impaired formation, abnormal loss from the body, or blockage of fluid removal can have serious consequences. When the transcellular compartment is unusually large, as in certain pathologic conditions (e.g., pleural effusions, ascites), it is referred to as the third space because this fluid is not readily exchangeable with the rest of the ECF.

Question 30

label ICF, ECF, ISF and plasma

Answer 30

Question 31

Calculation of the plasma volume from total blood volume and Htc: Plasma =

Answer 31

Plasma = TBV(1-Hct)

Question 32

Taking an example of a 70 kg male adult, if his TBW is approximately 60% of his body weight, calculate the weight/volume of his TBW, ICF, ECF, ISF, plasma, and TBV below (1 kg water = 1L water): (note 2 formulas for TBV and calculations used)

Answer 32

(note, practice TBV equations)

Question 33

3 factors that influence amount of TBW:

Answer 33

**1) adipose tissue:** * contains low percentage of water (about 10%) * less than most other tissues (ex: muscle = 75% water) * for this reason: * a lean person will have a higher percentage of body weight that is water * an obese person will have a lower percent of body weight that is water **2) gender:** * adult women tend to have less water than men because women tend to have more subcutanous fat and less muscle mass than men (for same reason as adipose tissue) **3) age:** * newborns have TBW = 75% and little fat * as people age, tend to lose muscle and add fat * hence, water declines with age * TBW of aged people is about 50% of total body weight

Question 34

Answer 34

A 60 kg adult should have about 60 (kg) x 20% = 12 (L) ECF. Since his hematocrit (Htc) is 0.45, an estimation of his plasma volume should be: Plasma (L) = ¼ ECF = ¼ x 12 (L) = 3 (L). An estimation of his total blood volume (TBV): TBV = Plasma / (1-Htc) = 3 / (1-0.45) = 5.45 (L). If he lost half of his blood, a 1-liter blood transfusion is not enough to compensate for his blood loss.

Question 35

the indicator dilution method: the volume of a fluid compartment in the body can be measured by \_\_\_, allowing \_\_\_, and analyzing \_\_\_

Answer 35

The indicator dilution method: the volume of a fluid compartment in the body can be measured by placing an indicator substance in the compartment, allowing it to disperse evenly throughout the compartment’s fluid, and analyzing the extent to which the substance becomes diluted

Question 36

How do we find volume of solution A?

Answer 36

Use indicator dilution method: - add dye: total amount of dye = 10 mg - when dye is evenly distributed, take some of the solution out and measure the concentration of the dye in that solution - dye has been diluted 1000 x the concentration of the original amount (see equation)

Question 37

Indicator Dilution Method formula volume =

Answer 37

volume = amount of dye/diluted concentration of dye

Question 38

If measuring TBW (total body water), what indicators (dyes) can we use (names of 3 and properties)

Answer 38

Want to use indicators (dyes) that can evenly distribute in all body fluids (throughout both ICF and ECF compartments) (can penetrate cell membrane and capillary wall) * radioactive water (tritium, 3H2O) or heavy water (deuterium, 2H2O) (takes a few hours) * Antipyrine = very lipid-soluble and small (can rapidly penetrate cell membranes and distribute itself uniformly throughout both ICF and ECF compartments)

Question 39

If measuring ECF volume (extracellular fluid), what indicators (dyes) do we want to use (4 and properties) (can also use what equation)

Answer 39

want dyes that only enter the ECF and not into the cell (ie, only in ISF and blood), 2 main types: - impermeant ions: Radioactive sulfate, radioactive Na+, radioactive CI-, thiocyanate, and thiosulfate, 125I-iothalamate * (tend to lead to overestimation of ECF because slowly enter the cell compartment) - inert sugars: mannitol and inulin * (tend to lead to an underestimate of ECF volume because they are excluded from some of the extracellular water)

Question 40

To measure plasma volume, what type of indicator (dye) should we use (examples of 2 and properties) (can also use what equation?)

Answer 40

want indicator that does not readily penetrate capillary walls but remains in the vascular system after injection. (i.e. dye thats only distributed in plasma, not in ESF or ISF) - radioiodinated serum albumin (125I-albumin) - Evans blue dye, which avidly binds with serum albumin. - can also use equation: plasma = total blood volume (1 - hct)

Question 41

If want to calculate volume of ICF (intracellular fluid)

Answer 41

There is no indicator that distributes only in the ICF. But ICF volume can be calculated from the difference between measurements of TBW volume and ECF volume **ICF volume = TBW volume – ECF volume**

Question 42

If want to calculate volume of ISF (interstitial fluid)

Answer 42

The interstitial fluid volume cannot be measured directly, but it can be calculated from the difference between ECF and plasma volumes ## Footnote **Interstitial fluid volume = ECF volume – plasma volume**

Question 43

Answer 43

Question 44

Ideal indicator requirements: (3)

Answer 44

Ideal indicator requirements: * Even distribution through the compartment * Does not leak from the compartment * Is not metabolized or excreted

Question 45

Answer 45

Question 46

•Electrolytes and water are \_\_\_

Answer 46

•Electrolytes and water are in a dynamic equilibrium between the different compartments.

Question 47

•Since most of the ECF is interstitial fluid, it is \_\_\_ (where as transcellular fluids are \_\_\_)

Answer 47

•Since most of the ECF is interstitial fluid, it is the bulk solution in which each body cell is bathed and lives. (Transcellular fluids, although part of ECF, are regional, so they are not a bulk solution.)

Question 48

Do body fluids stay in their compartments.

Answer 48

No! * Body fluids do not statically stay in their compartments.

Question 49

Not only are body fluids dynamic and equilibrate inside internal fluid compartments, but \_\_\_

Answer 49

* Not only are body fluids dynamic and equilibrate inside internal fluid compartments, but there is also continuous exchange of fluid and solutes with the external environment. * Overall, a high variable daily fluid intake must be carefully matched by equal output from the body to keep body fluid volumes constant.

Question 50

Loss of water from lungs and skin (route and amount)

Answer 50

* Lungs: * via respiration * 350 ml * Skin: * via evaporation * 350 ml = Significant daily insensible water loss.

Question 51

difference between sweating and water evaporation from sweat

Answer 51

Water evaporation from skin (~350 ml/day, invisible) is different from sweat (100 ml/day, visible)!!! The former is a physical process, whereas the latter is a biological process through glands.

Question 52

How is this first topic of body fluids (Volume & Distribution) related to the concept of homeostasis of the internal environment?

Answer 52

The maintenance of the homeostasis of the internal environment involves the maintenance of the appropriate volumes of body fluids in various compartments.

Question 53

Answer 53

F

Question 54

Answer 54

B

Question 55

Answer 55

E

Question 56

Answer 56

True

Question 57

Answer 57

Negative feedback control

Question 58

Answer 58

Intracellular fluid (ICF); extracellular fluid (ECF)

Question 59

7. The normal range of the TBW ranges from \_\_\_\_% to \_\_\_\_% of body weight, averaging around \_\_\_\_\_% for an adult. The TBW is about \_\_\_\_% for a newborn.

Answer 59

50; 70; 60; 75

Question 60

8. The ICF is about 40% of total body weight. True or false?

Answer 60

True

Question 61

9. The ICF is about 2/3 of total body water. True or false?

Answer 61

True

Question 62

10. The ECF is about 20% of total body weight, or 1/3 of total body water. True or false?

Answer 62

True

Question 63

11. ISF is about 3/4 of ECF, which is about 15% of total body weight. True or false?

Answer 63

True

Question 64

12. Plasma is about 5% of total body weight. True or false?

Answer 64

True

Question 65

13. Measurements taken after an intravenous injection of inulin indicate that the substance appears to be distributed throughout 22% to 26% of the total body water (TBW). This finding suggests that inulin most likely is A.excluded from the body cells. B.distributed uniformly throughout the TBW volume. C.restricted to the plasma compartment. D.neither excreted nor metabolized by the body. E.not freely diffusible through the capillary wall.

Answer 65

A

Question 66

Answer 66

D

Question 67

15. Transcellular fluids include fluids in the synovial, peritoneal, pericardial, and intraocular spaces as well as cerebrospinal fluids. True or false?

Answer 67

true

Question 68

16. Transcellular fluid is an additional small subcompartment of ICF. True or false?

Answer 68

False

Question 69

. A 70 kg female at the age of 40 tends to have less body fluid than a male with the same weight and at the same age. True or false?

Answer 69

true

Question 70

18. Body fluids are dynamic because (select all that apply) A.Plasma is rapidly circulating throughout the entire body. B.Fluid (containing various solutes) exchanges between plasma and ISF across the capillary wall. C.Water exchanges between ECF and ICF across cell membrane by osmosis (you will learn this in next physiology session). D.Solutes transport across cell membrane by various membrane transport mechanisms (you will learn this in subsequent session). E.Lymphatic fluids flow from ISF to plasma (you will learn this in the session on the cardiovascular system).

Answer 70

All

Question 71

19.A Kaplan question: A research physiologist decides to use a marker to measure the volume of the extracellular fluid compartment in a volunteer medical student. Which of the following substances would he most likely use? A.Tritium B.Cresyl violet C.Evans blue D.131I-albumin E.Inulin

Answer 71

E

Question 72

20. In steady state, daily fluid gain and loss of an adult body equilibrates around 2300 ml with great variations. True or false?

Answer 72

True

Question 73

21. Metabolism usually generates about 500 ml water daily. True or false?

Answer 73

False

Question 74

22. Daily insensible water loss includes A. water loss in feces and by sweating B. water loss through urine C. water loss via respiration about 350 ml D. water loss via skin evaporation about 350 ml E. C and D

Answer 74

E

Question 75

23. Your body tells you that the water loss in your body is greater than the water gain (unequilibrium) by \_\_\_\_\_\_\_\_\_\_. A. a feeling of thirst B. a behavior of frequent urination

Answer 75

A

Question 76

. So you drink water to equilibrate the water balance and thus a steady state of water metabolism is restored and you no longer feel thirsty. However, if you drink more water than your body needs to balance the gain and loss of water, you A. urinate more. B. eat more. C. sweat more. D. breathe faster.

Answer 76

A

Question 77

25.Your behaviors of drinking water due to thirst or frequent urination tells you that your body is using the negative feedback principle to maintain the homeostasis of body water equilibrium. The direct underlying mechanisms of making you drink or urinate to correct the water imbalance should belong to A. the sensory system of the negative feedback loop B. the control center of the negative feedback loop C. the effector system of the negative feedback loop D. all of the above

Answer 77

C

Question 78

26. What other causes may result in extra loss of body fluid? A. severe vomiting B. severe diarrhea C. sweating a lot during heavy exercise D. hyperventilation E. hemorrhage F. all of the above

Answer 78

F

Question 79

27. An individual has a blood volume of 6 L and a plasma volume of 3.3 L. Which one of the following statements is correct? He has a hematocrit of A. 0.60. B. 0.55. C. 0.45. D. 0.33. E. None of the above

Answer 79

C

Question 80

fluid intake includes (2 and how much)

Answer 80

1) fluids ingested = 2100 ml 2) fluids from metabolism = 200 ml (total fluid input = 2300 ml)