Chapter 11- Nurtition
42) Fat tissue contains more water than muscle tissue. T/F
FALSE
44) Body water increases with age T/F
FALSE
46) Water is the predominant body component in men, but not in women. T/F
FALSE
98) What is "enhanced water"?
It is any water product that has added ingredients to improve its taste and increase its nutrient content. Enhanced water may be fortified with vitamins, fiber, caffeine, herbs, protein, and even oxygen. It typically also contains sweeteners, which may add kilocalories.
92) What does it mean to say that cell membranes are selectively permeable?
It means that some substances can cross the membrane more easily than others.
41) Water is the most abundant substance in the body. T/F
TRUE
91) What is water balance?
a state of equilibrium when the intake of water equals the amount of water excreted
76) What are the main sources of water intake?
food, beverages, and metabolic water
77) What is metabolic water?
water generated through metabolic reactions
80) Describe two ways to monitor hydration.
• Measure weight before and after physical activity (vigorous exercise or labor) to check fluid loss. • Monitor urine color; dark color indicates need for more fluid.
35) What can result from hypovolemia? A) fainting B) diarrhea C) rapid breathing D) increased heart rate
A
4) What is the approximate percentage of water in fat tissue? A) 10-40 percent B) 40-60 percent C) 60-70 percent D) 70-90 percent
A
96) Explain how public water supplies in the United States are made safe to drink.
All municipal water is sent to a treatment plant where dirt and debris are filtered out, bacteria are killed, and other contaminants are removed. The EPA oversees water quality with national standards that measure possible contaminants. In addition, some households also filter their water with in-home systems.
88) What are cations and anions?
Both are electrolytes. Cations are ions with a positive charge, whereas anions are ions with a negative charge.
16) The sodium-potassium pump is a(n) A) electrolyte. B) specialized membrane. C) protein. D) drug.
C
20) Which of the following releases ADH? A) hypothalamus B) kidneys C) pituitary gland D) adrenal glands
C
22) On average, a well-balanced 2,200-kilocalorie diet is expected to provide ________ of water. A) 8 cups B) 10 cups C) 12 cups D) 16 cups
C
24) Consumption of pharmaceutical diuretics increases the risk of A) increased sodium reabsorption. B) increased calcium reabsorption. C) loss of potassium. D) loss of magnesium.
C
29) Which of the following statements is true about electrolytes? A) They carry a positive electrical charge only. B) They carry a negative electrical charge only. C) They may carry a positive or negative charge. D) They carry no electrical charge at all.
C
3) What is the approximate percentage of water in muscle tissue? A) 30 percent B) 45 percent C) 65 percent D) 90 percent
C
33) What is hypokalemia? A) a form of water intoxication B) an extreme form of dehydration C) a very low level of blood potassium D) a very low level of sodium in the blood
C
36) Which of the following is a vasoconstrictor that is released when blood pressure falls or sodium concentration in the blood is reduced? A) ADH B) renin C) angiotensin D) aldosterone
C
37) On average, what percentage of an individual's daily water intake comes from beverages? A) 60 percent B) 70 percent C) 80 percent D) 90 percent
C
38) Which food has the greatest water content? A) beef B) ice cream C) oatmeal D) cucumber
C
97) List some environmental concerns about bottled water.
Concerns include increased energy consumption, greenhouse gas emissions, waste, and the environmental effect of water extraction. The waste management of plastic water bottles is a serious problem, along with the environmental cost of producing the bottles.
15) The basic process that occurs during osmosis is A) condensation. B) active transport. C) hydrolysis. D) diffusion.
D
18) Which organ plays an important role in regulation of blood volume? A) liver B) bladder C) lungs D) kidneys
D
21) The mechanism of thirst and fluid intake is stimulated by A) a decrease in blood pressure. B) an increase in osmolality. C) a decrease in blood volume. D) all of the above
D
27) Which of the following are characteristics of tap water in the United States? A) It is clean. B) It is safe. C) It is cheap. D) all of the above
D
31) The protection that water in the body affords to the brain and other vital organs is an example of its function as a A) lubricant. B) metabolic agent. C) universal solvent. D) protective cushion.
D
39) Which of the following safe metals found in tap water typically adds to its "hardness"? A) iron B) lead C) tungsten D) magnesium
D
40) Around ________ of Americans get fluoride in their tap water, which helps reduce the level of dental caries. A) one-fourth B) one-third C) one-half D) two-thirds
D
5) Who has more body water by percent body weight? A) a sedentary adult female (40 years) B) a sedentary adult male (40 years) C) an adult female athlete (45 years) D) a week-old infant
D
7) Water can be described as A) a lubricant. B) a heat buffer. C) a solvent. D) all of the above
D
9) Under normal conditions, which of the following contributes the most to loss of body water? A) stools B) lungs C) sweat D) urine
D
49) The composition of the diet does not influence the amount of water lost through the intestines each day. T/F
FALSE
50) Interstitial fluid is a type of intracellular fluid. T/F
FALSE
52) The main mineral in ECF is potassium. T/F
FALSE
55) If sodium ions move into the cell, water moves out of the cell to balance it. T/F
FALSE
57) The sodium-potassium pump is a specialized mechanism found only in nerve and muscle cells. T/F
FALSE
59) The amount of water that an individual requires is not influenced by age, gender, or environmental conditions. T/F
FALSE
62) Generally speaking, bottled water does not contain any contaminants or impurities T/F
FALSE
63) Drinking water and other beverages is the only way to satisfy our daily water needs. T/F
FALSE
64) It is best to consume bottled water because tap water has too many contaminants. T/F
FALSE
66) Caffeine consumption is strongly associated with risk of dehydration. T/F
FALSE
68) Although consumption of too little water can be dangerous, excess water consumption does not have any associated risks. T/F
FALSE
69) A 1 to 2 percent loss of body water cannot produce any significant impact on water balance. T/F
FALSE
70) Hypotension is not a particular concern because it has no deleterious effects on the body. T/F
FALSE
73) During digestion and in catabolism, water breaks down large molecules through the process of osmosis. T/F
FALSE
87) Explain the difference between insensible water loss and sweating.
Insensible water loss is not perceptible. It involves water lost through the skin and through breathing, but not as a result of sweating, which is perceptible.
75) Older drinkers of alcohol and habitual consumers of caffeine may develop a tolerance toward the diuretic effects of these beverages. T/F
TRUE
84) Briefly describe the mechanism of the sodium-potassium pump.
• Pump is activated when concentration of sodium increases. • Three sodium ions and one ATP bind to the pump inside the cell. • ATP provides energy to change the shape of the protein (pump). • Sodium ions get transported out. • The pump binds two potassium ions from ECF. • The shape of the protein changes again. • A single phosphate from hydrolyzed ATP is released inside the cell. • The shape of the protein changes again. • The bound potassium ions are released inside the cell.
82) Describe how water helps regulate body temperature.
• Water has high specific heat. • Water in blood carries heat to skin surface. • Heat is released at skin surface. • Sweat evaporates. • Skin and blood get cooled.
86) How do pharmaceutical diuretics help treat hypertension?
• inhibit the reabsorption of sodium ions • increased sodium excretion causes increased water excretion • reduction of blood volume • reduction in blood pressure
83) List the organs through which water excretion can occur.
• kidneys • large intestine • skin • lungs
81) List the functions of water in the body.
• universal solvent • transport medium • maintains body temperature • lubricant • maintains cell structure • participates in chemical reactions • plays a role in acid-base balance
85) List the hormones and enzyme that help regulate blood volume, and explain their function in the retention and excretion of water.
• ADH (stimulates fluid intake/reduces urine output) • Angiotensin (stimulates kidneys to reabsorb water and salts) • Aldosterone (stimulates sodium reabsorption) • Renin (reabsorbs water and salts)
10) Which of the following food groups contains the most water? A) fruits and vegetables B) grains C) meats D) nuts and oils
A
13) Extracellular fluid contains more ________ than intracellular fluid. A) sodium B) potassium C) proteins D) organic acids
A
14) Which of the following has the greatest effect on fluid balance? A) sodium B) potassium C) calcium D) magnesium
A
19) The thirst mechanism is initiated by which part of the brain? A) hypothalamus B) medulla C) cortex D) none of the above
A
2) Factors that determine the distribution of water in the body include all of the following except A) height. B) age. C) gender. D) body composition.
A
25) What is most likely to happen as result of loss of water from the ECF? A) Water from the ICF will move into the ECF. B) Sodium concentrations will increase in the ECF. C) Potassium concentrations will increase in the ICF. D) None of the above will happen.
A
11) What is the average intake of water per day? A) 1 quart B) 2 quarts C) 1 gallon D) 2 gallons
B
1) The average healthy body is composed of ________ water. A) 0-40 percent B) 30-50 percent C) 45-75 percent D) 80-100 percent
C
47) An individual can survive for weeks without water. T/F
FALSE
99) Why is dehydration a special concern for children, the elderly, and individuals who are very physically active?
For those groups, the health consequences of dehydration can be severe. Normally, people can compensate for fluid loss by quenching their thirst and eating a balanced diet. But the elderly and those who engage in vigorous work or exercise may be at risk of severe dehydration unless they take additional measures to stay properly hydrated.
90) Explain the role of water in the chemical reactions of hydrolysis and condensation.
Hydrolysis occurs during digestion, when water helps break down (hydrolyze) the bonds that hold carbohydrates, proteins, and fats together, thus allowing for absorption of nutrients. The opposite occurs in condensation, when molecules are combined, such as when glucose is stored as glycogen in the liver and muscle. This reaction releases a water molecule from every bond formed.
79) How is the pumping of sodium and potassium ions important for the cell?
It prevents the solutes and water from building up in the cell and keeps the cell from swelling up and bursting.
89) What are the symptoms of hypokalemia, and what is the remedy?
Symptoms include lowered blood pressure, muscle weakness and cramps, and constipation. The remedy is to increase potassium intake, either through foods or supplements.
43) Males have more body water than females because they have increased muscle mass. T/F
TRUE
45) The fact that water is polar makes it an excellent solvent T/F
TRUE
48) All foods contain some water. T/F
TRUE
51) Intracellular fluid (ICF) and extracellular fluid (ECF) have different mineral compositions. T/F
TRUE
53) When salt dissolves, the sodium and chloride ions dissociate in solution. T/F
TRUE
78) What is osmosis?
movement of a solvent across a semi-permeable membrane from an area of weak solute concentration to an area of high solute concentration
54) Electrolytes help maintain water balance in the various cellular compartments. T/F
TRUE
56) The mechanism of the sodium-potassium pump is one that involves active transport. T/F
TRUE
58) A change in electrical charge drives the absorption of various nutrients in the small intestine T/F
TRUE
60) Minerals have a significant effect on blood pressure T/F
TRUE
61) Blood volume is the key element that regulates blood pressure. T/F
TRUE
65) Overconsumption of caffeine and alcohol can upset fluid balance. T/F
TRUE
67) Alcohol consumption has a more significant effect on dehydration than caffeine consumption. T/F
TRUE
71) Water has the ability to attract other molecules because it is polar. T/F
TRUE
72) Water has a high specific heat, which allows it to behave as a coolant. T/F
TRUE
74) The fluid found inside the blood and lymph vessels constitutes the intravascular fluid. T/F
TRUE
12) Which of the following factors can affect insensible water loss? A) sweating B) arid climate C) high temperature D) all of the above
B
17) Which of the following is not a true statement about the movement of ions? A) The concentration of ions affects the electrical charges on either side of the membrane. B) The movement of water is independent of the movement of ions. C) The change in the concentration of specific ions affects the movement of other ion species between the different compartments. D) The ion concentrations set up an osmotic gradient across membranes.
B
23) What is the mechanism of action of the diuretic effect of water and alcohol? A) They stimulate ADH. B) They inhibit ADH. C) They stimulate renin. D) They inhibit renin.
B
26) What effect do diuretics have on the body? A) They contribute to water gain. B) They contribute to water loss. C) They help produce more metabolic water. D) They stimulate the brain.
B
28) All of the following can be symptoms of dehydration except A) lethargy. B) diarrhea. C) dry mouth. D) rapid breathing.
B
30) Which of the following is an enzyme that plays a role in the excretion of water based on blood volume? A) ADH B) renin C) angiotensin D) aldosterone
B
32) What is typically the first physical sign of dehydration? A) thirst B) fatigue C) rapid pulse D) low urine output
B
34) Consuming too much _________ can cause hyponatremia. A) salt B) water C) alcohol D) potassium
B
6) A liquid in which substances dissolve is called a(n) A) lubricant. B) solvent. C) enzyme. D) acid.
B
8) Which of the following properties of water allow it to help maintain body temperature? A) polarity B) specific heat C) universal solvency D) transport capacity
B
95) Describe hyponatremia and its causes and possible effects.
It is a dangerously low level of sodium in the blood that can result from water intoxication or a lack of sodium during heavy exercise. Effects can include swelling of the brain, fatigue, confusion, disorientation, and even death.
94) What is hypovolemia, and what are the symptoms?
It is a low blood volume, which may result from water loss in the body. Symptoms include reduced blood pressure and possibly hypotension, which may in turn lead to reduced cardiac output, impaired digestion, and fainting or blacking out.
93) Define osmolality.
It is a measurement of the concentration of solutes per kilogram of solvents in a solution (the concentration of particles in a solution).
100) Describe the cornerstone method and its recommendations.
It is a method of monitoring hydration that involves measuring body weight before and after long bouts of vigorous physical activity or labor and noting changes. Post-activity weight loss is due to loss of body water, which must be replenished. In general, for every pound of weight lost in water, 16 fluid ounces of water should be consumed. If weight gain is noted, overhydration is likely, and less fluid should be consumed before the next activity.
