Chapter 7

Question 1

Identify and describe four nutrients that function as electrolytes in our bodies.

Answer 1

Sodium
Potassium
Chloride
Phosphorus

Question 2

Describe the functions of water in our bodies.

Answer 2

Water is an excellent solvent because it can dissolve many different substances.
The dissolved materials, or solutes, include ions, sugars, amino acids, vitamins, and minerals.

Blood volume is the amount of fluid in the blood.
Increased blood volume can cause blood pressure to rise.
Decreased blood volume can cause low blood pressure.

The high heat capacity of water means that the temperature of our body fluids remains quite stable.
Sweating releases heat as the evaporation of water from the skin cools the skin and blood. Fluids protect and lubricate body tissues.

Cerebrospinal fluid protects the brain and spinal column.
Amniotic fluid protects the fetus.
Synovial fluid is a lubricant around joints.
Digestive secretions allow for easy passage of material.

Question 3

Describe how electrolytes assist in the regulation of healthful fluid balance.

Answer 3

Electrolytes help regulate fluid balance.

Water follows the movement of electrolytes, moving by osmosis to areas where the concentration of electrolytes is high.
This allows for the controlled movement of fluids into and out of cells.

Question 3

Describe how electrolytes assist in the regulation of healthful fluid balance.

Answer 3

Electrolytes help regulate fluid balance.

Water follows the movement of electrolytes, moving by osmosis to areas where the concentration of electrolytes is high.
This allows for the controlled movement of fluids into and out of cells.

Question 4

Describe the avenues of fluid intake and excretion in our bodies.

Answer 4

Fluid is obtained from beverages, food, and metabolic reactions.

Most water enters the body through beverages
Some foods have very high water contents (many fruits and vegetables)
Metabolic water is a product of many chemical reactions in the body and contributes 10-14% of the body’s needs Fluid is lost through urine, sweat, evaporation, exhalation, and feces.

Sensible water loss includes losses through urine and sweat.

Insensible water loss includes losses through evaporation and exhalation.

Question 4

What is hyperkalemia?

Answer 4

Hyperkalemia is a high blood potassium level

Can occur in patients with kidney disease

Question 4

Hyponatremia?

Answer 4

What if you drink too much water?

Becoming over hydrated is rare
Can result in a dilution of sodium (hyponatremia)

Question 4

Identify food sources of potasium

Answer 4

Processed foods are usually low in potassium

Fresh fruit and vegetables and whole grains are good sources of potassium

Question 4

Identify functions of sodium

Answer 4

The major positively charged electrolyte in the extracellular fluid
Fluid and electrolyte balance
Associated with blood pressure and pH balance in the body
Required for nerve impulse transmission

Question 4

Identify functions of phosphorus

Answer 4

The major negatively charged electrolyte in the intracellular fluid
Required for fluid balance
Critical role in bone formation
Regulates biochemical pathways by activating or deactivating enzymes
Found in ATP, DNA, RNA

Question 4

Identify functions of potasium

Answer 4

The major positively charged electrolyte in the intracellular fluid
Fluid and electrolyte balance
Very important in muscle contractions and transmission of nerve impulses
High potassium intake helps to maintain a lower blood pressure

Question 4

Identify the organs responsible for maintaining fluid balance

Answer 4

Taking in water

Fluid is obtained from beverages, food, and metabolic reactions.

Most water enters the body through beverages
Some foods have very high water contents (many fruits and vegetables)
Metabolic water is a product of many chemical reactions in the body and contributes 10-14% of the body’s needs

Loss of water

Fluid is lost through urine, sweat, evaporation, exhalation, and feces.

Sensible water loss includes losses through urine and sweat.

Insensible water loss includes losses through evaporation and exhalation.

Question 4

Define hypertension and list some ways we can change our lifestyles to reduce hypertension.

Answer 4

high blood pressure

Can be reduced by decreasing chloride intake.

Question 4

What is the AI for sodium?.

Answer 4

AI = 1.5 grams/day (1,500mg)

Several health organizations recommend sodium intake of less than 2.3 g/day

Question 4

Identify nutrients that have been shown to improve blood pressure levels

Answer 4

Potasium

Question 4

Identify food sources of sodium

Answer 4

Processed foods and restaurant foods are surprisingly high in sodium

Question 4

Identify food sources of phosphorus

Answer 4

Found widespread in many foods

Found in high amounts in foods that contain protein (e.g., meat, milk, eggs)

Question 4

Identify predominant electrolytes in the extracellular and intracellular fluid

Answer 4

In extracellular fluid, Na+ and Cl- predominate

In intracellular fluid, K+ and HPO42- are the predominant electrolytes.

Question 4

Identify how the thirst mechanism is stimulated and where it is located

Answer 4

Thirst mechanism: cluster of nerve cells in the hypothalamus that stimulate your desire to drink in response to:

Increase in concentration of salts in blood
Decrease in blood volume and blood pressure
Dryness in mouth and throat

Question 4

Identify groups most vulnerable to dehydration

Answer 4

Infants and the elderly are especially vulnerable

Question 4

What is blood pressure?

Answer 4

During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure.
Systolic-90–119
It measures the amount of pressure that blood exerts on arteries and vessels while the heart is beating.
Systolic represents the maximum pressure exerted on the arteries.
Diastolic-60–79
It is the pressure that is exerted on the walls of the various arteries around the body in between heart beats when the heart is relaxed.
Diastolic represents the minimum pressure in the arteries.