Chapter 8

Question 1

water makes up what percentage of a person’s weight?

Answer 1

60%

Question 2

what is the most indispensable nutrient?

Answer 2

water

Question 3

water can be a…

Answer 3

cleansing agent, lubricant and cushion, universal solvent, and coolant

Question 4

water balance

Answer 4

the balance between water intake and water excretion, which keeps the body’s water content constant.

Question 5

dehydration

Answer 5

loss of water. The symptoms progress rapidly, from thirst to weakness to exhaustion and delirium, and end in death.

Question 6

water intoxication

Answer 6

a dangerous dilution of the body’s fluids resulting from excessive ingestion of plain water. Symptoms are headache, muscular weakness, mental confusion, seizures, and coma; fatalities can occur.

Question 7

how does the hypothalamus respond to low cellular fluid, concentrated blood particles, and low blood pressure?

Answer 7

initiating nerve impulses to the brain that register as “thirst.” also signals the pituitary gland to release a hormone that directs the kidneys to shift water back into the bloodstream from the fluid destined to become urine.

Question 8

caffeine acts as a diuretic. what does that mean?

Answer 8

a compound, usually a medication, causing increased urinary water excretion; a “water pill.”

Question 8

caffeine acts as a diuretic. what does that mean?

Answer 8

a compound, usually a medication, causing increased urinary water excretion; a “water pill.”

Question 9

metabolic water

Answer 9

water generated in the tissues during the chemical breakdown of the energy-yielding nutrients in foods.

Question 10

water occurs as…

Answer 10

hard or soft water

Question 11

hard water

Answer 11

water with high calcium and magnesium concentrations.

Question 12

soft water

Answer 12

water with a high sodium concentration.

Question 13

what water makes more bubbles with less soap?

Answer 13

soft water

Question 14

what water leaves a ring on the tub, a jumble of rocklike crystals in the teakettle, and a gray residue in the wash?

Answer 14

hard water

Question 15

what’s the problem with soft water?

Answer 15

may aggravate hypertension. more easily dissolves certain contaminant metals, such as cadmium and lead, from pipes.

Question 16

bottled water is how many times more than tap water?

Answer 16

250 to 10,000 times more

Question 17

all drinking water originates from where?

Answer 17

surface water or ground water

Question 18

do ions dissolved in water carry an electrical current?

Answer 18

yes. these electrically charged ions are called electrolytes.

Question 19

is sodium outside or inside the cell?

Answer 19

sodium is outside, potassium is inside

Question 20

fluid and electrolyte imbalance

Answer 20

failure to maintain the proper amounts and kinds of fluids and minerals in every body compartment; a medical emergency.

Question 21

can minerals help balance the acid-base balance (pH)?

Answer 21

yes

Question 22

what’s the most abundant mineral in the body?

Answer 22

calcium

Question 23

where is most of the calcium stored in the body?

Answer 23

bones and teeth

Question 24

explain the roles of calcium in body fluids

Answer 24

Regulates the transport of ions across cell membranes and is particularly important in nerve transmission. Helps maintain normal blood pressure. Plays an essential role in the clotting of blood. Is essential for muscle contraction and therefore for the heartbeat. Activates cellular enzymes that regulate many processes.

Question 25

what organ systems respond to the body's need for calcium?

Answer 25

The intestines increase their absorption of calcium. The kidneys prevent calcium loss in the urine. The bones release more calcium into the blood.

Question 26

bone density

Answer 26

a measure of bone strength, the degree of mineralization of the bone matrix.

Question 27

what percentage of calcium do adults absorb that are ingested?

Answer 27

20-30%. breastfed infants absorb 60%, and children in puberty absorb 35%

Question 28

what interferes with calcium absorption?

Answer 28

Fiber and the binders phytate (in whole grains) and oxalate (in vegetables)

Question 29

what are good sources of calcium?

Answer 29

sardines, milk, tofu, yogurt, cheddar cheese, turnip greens, waffle

Question 30

what's the 2nd most abundant mineral in the body?

Answer 30

phosphorus

Question 31

where is most of the body's phosphorus found?

Answer 31

bones and teeth

Question 32

explain the functions of phosphorus

Answer 32

Phosphorous salts are critical buffers, helping to maintain the acid-base balance of cellular fluids. (Note that the mineral is phosphorus. The adjective form is spelled with an -ous, as in phosphorous salts.) Phosphorus is part of the DNA and RNA of every cell and thus is essential for growth and renewal of tissues. Phosphorous compounds carry, store, and release energy during metabolism of energy nutrients. Phosphorous compounds act as cofactors, assisting many enzymes in extracting the energy from nutrients. Phosphorus forms part of the molecules of the phospholipids that are the principal components of cell membranes (discussed in Chapter 5). Phosphorus is present in some proteins.

Question 33

what's the best source of phosphorus?

Answer 33

animal protein

Question 34

what are good sources of phosphorus?

Answer 34

cottage cheese, milk, navy beans, salmon, sirloin steak, sunflower seeds

Question 35

what are the functions of magnesium?

Answer 35

Serves as a cofactor for hundreds of enzymes. Is needed for the release and use of energy from the energy-yielding nutrients. Is a necessary part of the cellular protein-making machinery. Is critical to normal nerve transmission, muscle contraction, and heart function.Footnote

Question 36

calcium promotes contraction of muscles and magnesium...

Answer 36

helps relax the muscles afterward

Question 37

what are good sources of magnesium?

Answer 37

spinach, black beans, soy milk, bran cereal, sunflower seeds, yogurt

Question 38

hyponatremia

Answer 38

an abnormally low concentration of sodium in the blood.

Question 39

what's the average US sodium intake?

Answer 39

3,500 mg

Question 40

what's the biggest contributor of sodium?

Answer 40

processed and restaurant foods

Question 41

which diet can help reduce sodium intakes?

Answer 41

the DASH diet (Dietary Approaches to Stop Hypertension)

Question 42

which mineral is important for maintaining a steady heartbeat?

Answer 42

potassium

Question 43

what are good sources of potassium?

Answer 43

orange juice, butternut squash, lime beans, wild salmon, baked potato, avocado

Question 44

which mineral forms a deadly green gas?

Answer 44

chloride

Question 45

what's the body's major negative ion?

Answer 45

chloride

Question 46

thyroxine needs what trace mineral?

Answer 46

iodine

Question 47

what's the major source of iodine?

Answer 47

the ocean

Question 48

iodine deficiency causes cells of the thyroid gland to enlarge, which creates a...

Answer 48

goiter

Question 49

does sea salt deliver a lot of iodine?

Answer 49

no, because iodine becomes a gas and flies off into the air during the salt-drying process.

Question 50

what foods are good for iodine?

Answer 50

seafood, vegetables grown in iodine-rich soil, and iodized salt. Other sources are bakery products and milk

Question 51

what's the function of zinc?

Answer 51

Protect cell structures against damage from oxidation.Footnote Make parts of the cells’ genetic material. Make the heme of hemoglobin.

Question 52

what are good sources of zinc?

Answer 52

oysters, beef steak, yogurt, shrimp, enriched cereal, pork chop,