Lecture 1-Body Fluid Compartments

Question 1

Daily intake of water—oral intake = ___ ml/day + synthesized by the body = ___ ml/day

Answer 1

Oral intake = 2100 ml/day + synthesized by the body = 200 ml/day

Total water intake = 2300 ml/day

Question 2

Loss of body water = ____ loss, ___ loss, loss in ___, loss by ___

Answer 2

Insensible loss, sweat loss, loss in feces, loss by kidneys

Question 3

Insensible loss = ___ ml/day

Answer 3

700 ml/day—350 ml lost via skin + 350 ml lost via lungs

Question 4

Loss in sweat = ___ ml/day

Answer 4

100 ml/day

Question 5

Loss in feces = ___ ml/day

Answer 5

100 ml/day

Question 6

Loss in urine = ___ ml/day

Answer 6

1400 ml/day

Question 7

Total body fluid is distributed mainly between two compartments: the ___ fluid and the ___ fluid; ___ fluid is divided into the ___ fluid and blood ___

Answer 7

The extracellular fluid and the intracellular fluid; extracellular fluid is divided into the interstitial fluid and blood plasma

Question 8

___ fluid = this compartment includes fluid in the synovial, peritoneal, pericardial, and intraocular spaces, as well as the cerebrospinal fluid; it is usually considered to be a specialized type of ___ fluid, although in some cases its composition may differ markedly from that of the plasma or interstitial fluid; this compartment constitutes ~ ___ to ___ liters

Answer 8

Transcellular fluid; it is usually considered to be a specialized type of extracellular fluid; all the transcellular fluids together constitute ~1-2 liters

Question 9

In a 70 kg adult man, the total body water is about ___% of the body weight, or about ___ liters

Answer 9

60% of the body weight, or about 42 liters

Question 10

Total body water depends on age, gender, and degree of obesity—T/F?

Answer 10

True

Question 11

As a person grows older, the percentage of total body weight that is fluid gradually ___ (increases/decreases); this is due in part to the fact that aging is usually associated with an increased percentage of the body weight being ___

Answer 11

The percentage of total body weight that is fluid gradually decreases; this is due in part to the fact that aging is usually associated with an increased percentage of the body weight being fat (so this decreases the percentage of water in the body)

Question 12

Body fluid compartments—intracellular fluid = ___ L

Answer 12

28 L

Question 13

Body fluid compartments—extracellular fluid = ___ L

Answer 13

14 L

Question 14

Body fluid compartments—interstitial fluid = ___ L

Answer 14

11 L

Question 15

Body fluid compartments—plasma = ___ L

Answer 15

3 L

Question 16

Fluid composition—extracellular vs. intracellular—plasma and interstitial fluids are ___ (similar/different) in composition; there is a highly permeable ___ (cell/capillary) membrane inbetween plasma and interstitial fluids; protein level is greater in the ___ (plasma or interstitial fluid) because of ___ (low/high) membrane permeability

Answer 16

Plasma and interstitial fluids are similar in composition; there is a highly permeable capillary membrane inbetween plasma and interstitial fluids; protein level is greater in the plasma because of low [capillary] membrane permeability

Question 17

Fluid composition—extracellular vs. intracellular—intracellular fluid is separated from extracellular fluid by ___ membrane; the cell membrane is highly permeable to ___, not ____, making it ___-permeable

Answer 17

Intracellular fluid is separated from extracellular fluid by cell membrane; the cell membrane is highly permeable to water, not electrolytes, making it semi-permeable

Question 18

Extracellular fluid has high concentrations of what two ions?

Answer 18

Sodium and chloride

Question 19

Intracellular fluid has high concentration of what (3) things?

Answer 19

Potassium, phosphate, and protein

Question 20

Gibbs Donnan Equilibrium—when two solutions containing ions are separated by a membrane that is permeable to some of the ions and not to others, a/an ___ is established; electrical and chemical energies on either side of the membrane are ___ and ___ to each other

Answer 20

An electrochemical equilibrium is established; electrical and chemical energies on either side of the membrane are equal and opposite to each other

Question 21

Fluid exchange and osmotic equilibrium—distribution of fluid between intracellular and extracellular compartments is determined by osmotic effect of ___

Answer 21

Small solutes

Question 22

Fluid exchange and osmotic equilibrium—___ or ___ (i.e.: sodium and chloride) determine distribution of fluids across the semi-permeable cell membrane [inbetween intracellular/extracellular compartments]

Answer 22

Electrolytes or small ions (i.e.: sodium and chloride)

Question 23

Fluid exchange and osmotic equilibrium—___ factors cause fluids to shift between intra/extracellular compartments; the reason for this is that the cell membranes are highly permeable to ___ but relatively impermeable to ___

Answer 23

Osmotic factors; the reason for this is that the cell membranes are highly permeable to water but relatively impermeable to small ions such as sodium and chloride

Question 24

The relative amounts of EXTRACELLULAR fluid distributed between the plasma and interstitial spaces are determined mainly by the balance of ___ and ___ forces across the capillary membrane

Answer 24

Hydrostatic and colloid osmotic forces across the capillary membrane

Question 25

Rate of osmosis—because cell membranes are relatively ___ to most solutes but are ___ to water (i.e.: they are selectively permeable), whenever there is a higher concentration of solute on one side of the cell membrane, ___ diffuses across the membrane toward the region of higher solute concentration

Answer 25

Because cell membranes are relatively impermeable to most solutes but are highly permeable to water (i.e.: they are selectively permeable), whenever there is a higher concentration of solute on one side of the cell membrane, water diffuses across the membrane toward the region of higher solute concentration

Question 26

If a solute such as sodium chloride is added to the extracellular fluid water rapidly diffuses from the cells through the cell membranes into the ___ fluid until the water concentration on both sides of the membrane becomes equal

Answer 26

Extracellular fluid

Question 27

If a solute such as sodium chloride is removed from the extracellular fluid, water diffuses from the extracellular fluid through the cell membranes and into the ___

Answer 27

Cells

Question 28

The rate of diffusion of water is called the rate of ___

Answer 28

Osmosis

Question 29

Mole is the term defining a specific quantity of ___

Answer 29

Molecules

Question 30

Osmole refers to the number of particles in ___, rather than molar concentration

Answer 30

Osmole refers to the number of particles in solution, rather than molar concentration

Question 31

One osmole (osm) = ___

Answer 31

1 mole (mol) 6.02 x 10^23

Question 32

Total number of particles in a solution is measured in ___

Answer 32

Osmole

Question 33

Osmolality = osmoles/___ of water

Answer 33

Osmoles/kg of water

^ Not really applicable to us

Question 34

Osmolarity = osmoles/___ of solution

Answer 34

Osmoles/liter of solution

^ More applicable to us

Question 35

Osmosis is the net diffusion of ___ across a selective membrane

Answer 35

Water

Question 36

Water moves from ___ water concentration to ___ water concentration

Answer 36

High water concentration to low water concentration

Question 37

___ refers to the amount of pressure required to prevent osmosis (pressure applied in opposite direction of osmosis)

Answer 37

Osmotic pressure

Question 38

Osmotic pressure of a solution is proportional to the concentration of osmotically active particles, independent of molecular size (big or small)—T/F?

Answer 38

True

Question 39

Molecules which dissociate when dissolved into solution have more osmotic effect—T/F?

Answer 39

True

Question 40

Osmolarity of body fluids—80% of the osmolarity of interstitial fluid and plasma is due to ___ and ___

Answer 40

Sodium and chloride

Question 41

Osmolarity of body fluids—plasma is 1 mOsm/L ___ (less than/greater than) interstitial fluid…why?

Answer 41

Plasma is 1 mOsm/L greater than interstitial fluid because plasma proteins maintain 20 mmHg greater pressure in capillaries than surrounding tissues

Question 42

Osmolarity of intracellular fluid is almost 50% due to ___ ions; remainder divided among other intracellular substances

Answer 42

Potassium ions

Question 43

Total osmolarity of each compartment is ___ mOsm/L

Answer 43

300 mOsm/L

Question 44

Because the plasma and interstitial fluid are separated only by highly permeable capillary membranes, their ionic composition is similar—T/F?

Answer 44

True

Question 45

The most important difference between the plasma and interstitial fluid is that there is a ___ (lower/higher) concentration of protein in the plasma

Answer 45

Higher concentration of protein in the plasma

Question 46

Because the capillaries have a ___ (low/high) permeability to plasma proteins, ___ (small/large) amounts of proteins are leaked into the interstitial spaces in most tissues

Answer 46

Because the capillaries have a low permeability to plasma proteins, small amounts of proteins are leaked into the interstitial spaces in most tissues

Question 47

Extracellular fluid osmolarity (interstitial fluid + plasma) is mostly due to ___ and ___ ions

Answer 47

Sodium and chloride ions (account for 80% of the total osmolarity in the interstitial/plasma compartments)

Question 48

Intracellular fluid osmolarity is mostly due to ___ ions

Answer 48

Potassium ions (account for 50%—the remainder is divided among many other intracellular substances)

Question 49

Large osmotic pressures can develop across cell membranes with relatively small changes in solute concentrations—T/F?

Answer 49

True

Question 50

Small changes in concentration of impermeable solutes cause little changes in cell volume—T/F?

Answer 50

False—can cause TREMENDOUS changes in cell volume

Question 51

If isotonic saline is added to the extracellular fluid compartment, the osmolarity of the extracellular fluid ___ (increases/decreases/does not change); therefore, ___ (osmosis/no osmosis) occurs through the cell membranes; the effect is a/an ___ (increase/decrease/no change) in extracellular fluid volume

Answer 51

If isotonic saline is added to the extracellular fluid compartment, the osmolarity of the extracellular fluid does not change; therefore, no osmosis occurs through the cell membranes; the effect is an increase in extracellular fluid volume

Question 52

If a hypertonic solution is added to the extracellular fluid, the extracellular osmolarity ___ (increases/decreases/does not change); therefore, ___ (osmosis/no osmosis) occurs and water moves into the ___ compartment; almost all the added sodium chloride remains in the ___ compartment and fluid diffuses from cells into the ___ space to achieve ___; the net effect is a/an ___ (increase/decrease/no change) in extracellular volume, a/an ___ (increase/decrease/no change) in intracellular volume, and a ___ (rise/decline) in osmolarity in both compartments

Answer 52

If a hypertonic solution is added to the extracellular fluid, the extracellular osmolarity increases; therefore, osmosis occurs and water moves into the extracellular compartment; almost all the added sodium chloride remains in the extracellular compartment and fluid diffuses from cells into the extracellular space to achieve osmotic equilibrium; the net effect is an increase in extracellular volume (greater than the volume of fluid added), a decrease in intracellular volume, and a rise in osmolarity in both compartments

Question 53

If a hypotonic solution is added to the extracellular fluid, the osmolarity of the extracellular fluid ___ (increases/decreases/does not change); extracellular water diffuses into the ___ until the intracellular and extracellular compartments have the same ___; both the intracellular and extracellular volumes are ___ (increased/decreased/unchanged) by the addition of hypotonic fluid, although the ___ (intracellular/extracellular) volume increases to a greater extent

Answer 53

If a hypotonic solution is added to the extracellular fluid, the osmolarity of the extracellular fluid decreases; extracellular water diffuses into the cells until the intracellular and extracellular compartments have the same osmolarity; both the intracellular and extracellular volumes are increased by the addition of hypotonic fluid, although the intracellular volume increases to a greater extent

Question 54

Sodium concentration abnormalities—hyponatremia = excess ___, loss of ___

Answer 54

Excess water, loss of sodium

Question 55

Conditions that can cause hyponatremia—___ and ___; ___ abuse; ___ disease; excess ___ retention (from what hormone?)

Answer 55

Diarrhea and vomiting; diuretic abuse; Addison’s disease (inadequate mineralocorticoid—Aldosterone/glucocorticoid secretion); excess water retention (from oversecretion of ADH/vasopressin)

Question 56

Sodium concentration abnormalities—hypernatremia = loss of ___, excess ___

Answer 56

Loss of water, excess sodium

Question 57

Conditions that can cause hypernatremia—lack of ___ (what hormone?); ___ (endocrine condition); ___hydration; ___ secretion (what hormone?)

Answer 57

Lack of ADH; diabetes insipidus; dehydration; aldosterone secretion

Question 58

Rapid changes in cell volume as a result of hyponatremia can have profound effects on tissue and organ function, especially the ___

Answer 58

Brain

Question 59

A rapid reduction in plasma sodium concentration, for example, can cause brain cell edema and neurological symptoms, including headache, nausea, lethargy, and disorientation—T/F?

Answer 59

True

Question 60

If plasma sodium concentration rapidly falls below ___ to ___ mmol/L, brain swelling may lead to seizures, coma, permanent brain damage, and death

Answer 60

Below 115 to 120 mmol/L

Question 61

Because the skull is rigid, the brain cannot increase its volume by more than about ___% without it being forced down the neck (herniation), which can lead to permanent brain injury and death

Answer 61

10%

Question 62

Hypernatremia can be caused by ___ loss or excess ___

Answer 62

Water loss or excess sodium

Question 63

Hypernatremia from primary loss of water can occur from an inability to secrete ___ hormone

Answer 63

An inability to secrete antidiuretic hormone—needed for the kidneys to conserve water

Question 64

Hypernatremia—as a result of lack of ADH, the kidneys excrete large amounts of ___ (dilute/concentrated) urine (a disorder referred to as ___), causing ___ and ___ (increased/decreased) concentration of sodium chloride in the extracellular fluid

Answer 64

As a result of lack of ADH, the kidneys excrete large amounts of dilute urine (a disorder referred to as “central” diabetes insipidus), causing dehydration and increased concentration of sodium chloride in the extracellular fluid

Question 65

Hypernatremia—in certain types of renal diseases, the kidneys cannot respond to antidiuretic hormone, causing a type of ___

Answer 65

“Nephrogenic” diabetes insipidus

Question 66

Hypernatremia d/t excessive sodium chloride in the extracellular fluid—this often results in ___hydration (de/over) because excess extracellular sodium chloride is usually associated with at least some degree of ___ retention by the kidneys

Answer 66

This often results in over hydration because excess extracellular sodium chloride is usually associated with at least some degree of water retention by the kidneys

Question 67

Hypernatremia—excessive secretion of the sodium-retaining hormone ___ can cause a mild degree of hypernatremia and overhydration

Answer 67

Aldosterone

Question 68

Sodium retention caused by increased aldosterone secretion also stimulates secretion of ___ hormone and causes the kidneys to reabsorb greater amounts of ___

Answer 68

Water

Question 69

Hypernatremia is much ___ (more/less) common than hyponatremia…why?

Answer 69

Much less common—because hypernatremia promotes intense thirst and stimulates secretion of antidiuretic hormone, which protects against a large increase in plasma and extracellular fluid sodium

Question 70

Severe symptoms of hypernatremia usually occur only with rapid and large increases in the plasma sodium concentration above ___ to ___ mmol/L

Answer 70

Above 158 to 160 mmol/L

Question 71

Correction of hypernatremia can be achieved by administering ___ or ___ solutions

Answer 71

Hypotonic or dextrose solutions

Question 72

It is prudent to correct hyper/hyponatremia ___ (slowly or quickly)

Answer 72

SLOWLY

Question 73

Edema = presence of excess fluid in ___; occurs mostly in the ___ fluid compartment

Answer 73

Presence of excess fluid in body tissue; occurs mostly in the extracellular fluid compartment

Question 74

Intracellular edema can occur in certain conditions—inflammation has a direct effect on ___ (increasing/decreasing) cell membrane permeability; ___ (increase/decrease) in cellular metabolic function; lack of ___ to cells; ___ (increased/decreased) blood flow, reducing oxygen and nutrient supply

Answer 74

Inflammation has a direct effect on increasing cell membrane permeability; decrease in cellular metabolic function; lack of nutrition to cells; decreased blood flow, reducing oxygen and nutrient supply

Question 75

Extracellular edema (excess fluid accumulation in extracellular spaces)—two general causes: 1) abnormal leakage from ___; 2) lymphatic failure to return fluids to ___

Answer 75

1) abnormal leakage from plasma

2) lymphatic failure to return fluids to blood

Question 76

Extracellular edema—abnormal leakage from plasma can result from excessive ___ filtration rate; filtration is dependent on ___ity and ___ of capillary; starling factors—___ pressure and ___ pressure

Answer 76

Excessive capillary filtration rate; filtration is dependent on permeability and surface area of capillary; starling factors—hydrostatic pressure and colloid osmotic pressure

Question 77

Extracellular edema—lymphatic failure to return fluids to blood can result from lymphatic ___, preventing return of ___ to plasma; ___ (increased/decreased) interstitial colloid osmotic pressure; cancer, surgery, infection (i.e.: ___)

Answer 77

Lymphatic blockage, preventing return of proteins to plasma; increased interstitial colloid osmotic pressure; cancer, surgery, infection (i.e.: filaria nematodes)

Question 78

Causes of extracellular edema—___ (increased/decreased) capillary pressure from excessive kidney retention of ___ and ___; ___ (low/high) venous pressure and venous constriction; ___ (increased/decreased) arteriolar resistance

Answer 78

Increased capillary pressure from excessive kidney retention of salt and water; high venous pressure and venous constriction; decreased arteriolar resistance

Question 79

Causes of extracellular edema—___ (increased/decreased) plasma proteins from loss in ___ (i.e.: ___ syndrome); denuded skin (i.e.: ___ and ___); failure to produce proteins (i.e.: ___ disease, ___nutrition)

Answer 79

Decreased plasma proteins from loss in urine (i.e.: nephrotic syndrome); denuded skin (i.e.: burns and wounds); failure to produce proteins (i.e.: liver disease, malnutrition)

Question 80

One of the most important causes of decreased plasma protein concentration is loss of proteins in the ___ in certain kidney diseases, a condition referred to as ___ syndrome

Answer 80

Loss of proteins in the urine in certain kidney diseases, a condition referred to as nephrotic syndrome

Question 81

Causes of extracellular edema—___ (increased/decreased) capillary permeability from immune reactions that cause release of histamine and other immune products; toxins; bacterial infections; vitamin deficiency, especially vitamin C; prolonged ischemia; burns

Answer 81

Increased capillary permeability

Question 82

Causes of extracellular edema—___ of lymph return—i.e.: cancer, infections (i.e.: filaria nematodes), surgery, congenital absence or abnormality of lymphatic vessels

Answer 82

Blockage of lymph return

Question 83

Edema caused by heart failure—the heart fails to pump blood normally from the ___ into the arteries, which raises ___ pressure and ___ pressure, causing ___ (increased/decreased) capillary filtration; the arterial pressure tends to ___ (rise/drop), causing decreased excretion of ___ and __ by the kidneys, which causes still more edema

Answer 83

The heart fails to pump blood normally from the veins into the arteries, which raises venous pressure and capillary pressure, causing increased capillary filtration; the arterial pressure tends to drop, causing decreased excretion of salt and water by the kidneys, which causes still more edema

Question 84

Edema caused by heart failure—blood flow to the kidneys is ___ (increased/decreased), which stimulates secretion of ___, causing increased formation of ___ and increased secretion of ___, both of which cause additional ___ and ___ retention by the kidneys

Answer 84

Blood flow to the kidneys is decreased, which stimulates secretion of renin, causing increased formation of angiotensin II and increased secretion of aldosterone, both of which cause additional salt and water retention by the kidneys

Question 85

Extracellular edema—summary of causes—___ (increased/decreased) capillary pressure; ___ (increased/decreased) plasma proteins; ___ (increased/decreased) capillary permeability; ___ of lymphatic return

Answer 85

Increased capillary pressure; decreased plasma proteins; increased capillary permeability; blockage of lymphatic return

Question 86

Virtually all the fluid in the interstitium is in the ___ form

Answer 86

Gel form

Question 87

Summary of safety factors that prevent edema—1) low interstitial ___; 2) ___ (increased/decreased) lymph flow; 3) “wash down” of interstitial fluid ___—as lymphatic flow ___ (increases/decreases), proteins are washed away

Answer 87

1) low interstitial compliance
2) increased lymph flow
3) “wash down” of interstitial fluid proteins—as lymphatic flow increases, proteins are washed away

Question 88

The total safety factor against edema is about ___ mm Hg; therefore, capillary pressure can ___ before significant edema occurs

Answer 88

Total safety factor = 17 mm Hg; capillary pressure can double before significant edema occurs

Total safety factor— -3 mm Hg from interstitial compliance; 7 mm Hg from lymph flow; 7 mm Hg from “wash down” of proteins from interstitial spaces
3+7+7 = 17 mm Hg

Question 89

The right kidney rests slightly lower than the left one d/t the presence of the liver on the right side—T/F?

Answer 89

True

Question 90

The ___ is the functional unit of the kidney

Answer 90

Nephron

Question 91

Plasma filtration occurs in the ___

Answer 91

Glomerulus

Question 92

Renal blood flow = ___% of cardiac output (___ ml/min)

Answer 92

22% of cardiac output (1100 ml/min)

Question 93

Renal blood flow—oxygen consumption in the kidneys varies directly with active transport of ___

Answer 93

Na+

Question 94

Highest metabolism occurs in the renal ___

Answer 94

Cortex

Question 95

On a per gram basis, renal blood flow is the highest of any organ—T/F?

Answer 95

True—because renal tissue makes up only 0.4% of body weight but receives 25% of cardiac output

Question 96

The kidneys are the most highly perfused major organs in the body—T/F?

Answer 96

True

Question 97

The high perfusion to the kidneys facilitates plasma filtration at rates as high as ___ to ___ ml/min in young adults

Answer 97

125 to 140 ml/min

Question 98

___ is the functional unit of the kidney

Answer 98

Nephron

Each kidney has 1.25 million nephrons

Question 99

Two types of nephrons = ___ and ___

Answer 99

Cortical and juxtamedullary

Question 100

Cortical nephrons = ___ (short/long) loops of Henle, extend to outer medulla; outnumber juxtamedullary nephrons ___:___

Answer 100

Short loops of Henle, extend to outer medulla; outnumber juxtamedullary nephrons 7:1

Question 101

Juxtamedullary nephrons—extend deep into the medulla with ___ (short/long) loops of Henle; play a big role in ___ urine

Answer 101

Long loops of Henle; play a big role in concentrating urine

Question 102

The kidney can regenerate new nephrons—T/F?

Answer 102

False—the kidney CANNOT regenerate new nephrons

Question 103

With renal injury, disease, or normal aging, the number of nephrons gradually ___ (increases/decreases)

Answer 103

Decreases

Question 104

After age 40 years, the number of functioning nephrons usually decreases about ___% every 10 years; thus, at age 80 years, many people have ___% fewer functioning nephrons than they did at age 40 years

Answer 104

After age 40 years, the number of functioning nephrons usually decreases about 10% every 10 years; thus, at age 80 years, many people have 40% fewer functioning nephrons than they did at age 40 years

Question 105

The nephron begins with ___ space

Answer 105

Bowman’s space

Question 106

The distal convoluted tubule comes into very close contact with the ___ (afferent/efferent) glomerular arteriole, and the modified cells of each form the ___ apparatus, a complex physiologic feedback control mechanism contributing in part to the precise control of intra- and extra-renal hemodynamics that is a hallmark feature of the normally functioning kidney

Answer 106

Afferent arteriole, and the modified cells of each form the juxtaglomerular apparatus

Question 107

Superficial cortical nephrons have their glomeruli in the ___ (inner/outer) cortex; they have ___ (shorter/longer) loops of Henle, which dip only into the ___ (inner/outer) medulla

Answer 107

Superficial cortical nephrons have their glomeruli in the outer cortex; they have shorter loops of Henle, which dip only into the outer medulla

Question 108

Juxtamedullary nephrons have their glomeruli near the corticomedullary border; they have ___ (smaller/larger) glomeruli, and thus have ___ (lower/higher) glomerular filtration rates (GFR); their loops of Henle dip deeper into the ___ (inner/outer) medulla and papilla, and are vital in the ___ of urine

Answer 108

They have larger glomeruli, and thus have higher glomerular filtration rates (GFR); their loops of Henle dip deeper into the inner medulla and papilla, and are vital in the concentration of urine

Question 109

___ = high-pressure capillary bed; the site of blood filtration

Answer 109

Glomerulus

Question 110

___ = funnel-like structure; ‘beginning’ of the nephron

Answer 110

Bowman’s capsule

Question 111

Each nephron has its own independent blood supply (renal arterioles and veins)—T/F?

Answer 111

True

Question 112

Where in the nephron is urine is formed, concentrated, and conveyed to the ureters? (4) parts

Answer 112

• Proximal convoluted tubule
• Loop of Henle
• Distal convoluted tubule
• Collecting duct