Chapter 12 Flashcards
What are the major roles of water in the body?
It carries nutrients and waste products throughout the body.
Maintains the structure of large molecules such as proteins and glycogen.
Participates in metabolic reactions.
Serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small molecules.
Acts as a lubricant and cushion around joints and inside the eyes, the spinal cord, and in pregnancy, the amniotic sac surrounding the fetus in the womb.
Aids in the regulation of normal body temperature, as the evaporation of sweat from the skin removes excess heat from the body.
Maintains the body’s blood volume.
What percentage of your body is water?
60 percent
Which nutrient is needed in the greatest amount by the body?
Water
Extracellular Fluid
The fluid outside the cells and it accounts for approximately one-third of the body’s water.
Intracellular Fluid
Fluid inside the cells, usually high in potassium and phosphate. It accounts for approximately two-thirds of the body’s water.
Interstitial Fluid
Fluid that surrounds each cell.
Intravascular Fluid
Fluid within the blood vessels.
Explain how fluid balance and blood pressure are each regulated in the body, including the hormones and organs involved.
Whenever blood volume or blood pressure falls too low, or whenever the extracellular fluid becomes too concentrated, the hypothalamus signals the pituitary gland to release antidiuretic hormone (ADH) which stimulates the kidneys to reabsorb water. The cells in the kidneys respond to low blood pressure by releasing an enzyme called renin which reabsorb sodium. The. The renin hydrolyzes angiotensinogen (a protein produced by the liver) to angiotensin I until another enzyme converts it to its active form angiotensin II, which is a powerful vasoconstrictor that narrows the diameters of blood vessels, raising blood pressure. Lastly, angiotensin II stimulates the release of the hormone aldosterone from the adrenal glands to signal the kidneys to excrete potassium and retain more sodium to allow water to flow.
Oral rehydration therapy (ORT)
A simple solution of sugar, salt, and water taken by mouth to treat dehydration caused by severe diarrhea.
Bicarbonate and Carbonic Acid
Protects the body against changes in acidity by acting as buffers.
The lungs control the concentration of carbonic acids by raising or lowering respiration rate.
The kidneys control the concentration of bicarbonate by either reabsorbing or excreting it.
Signs of Dehydration
1-2% of Body Weight Loss - Thirst, weakness, fatigue, loss of appetite.
3-4% - Impaired physical performance, dry mouth, flushed skin, apathy.
5-6% - Headache, sleepiness, impaired temperature regulation, increased respiratory rate, difficulty concentrating.
7-10% - Dizziness, loss of balance, collapse, exhaustion.
How much water is required by the body each day?
About 15.5 cups (3.7 liters) of fluids a day for men and about 11.5 cups (2.7 liters) of fluids a day for women.
How must your fluid requirement be met?
Through water, beverages, and food.
What fluids that we drink count towards our daily fluid intake?
Water, lower-fat milk and sugar-free drinks, including tea and coffee, all count.
How should your urine look if you are well hydrated?
Pale straw or transparent yellow
Give 3 tips/strategies for increasing your water intake.
Replace drinks with water, eat more hydrating foods, and adding flavor by putting fruits in water.
Describe the differences between the major and trace minerals.
Major minerals are essential mineral nutrients that the body require in large amounts and trace minerals are require in smaller amounts.
Name the major minerals.
Sodium, chloride, potassium, calcium, phosphorus, magnesium, and sulfur.
List the factors that affect the bioavailability, absorption, and retention of minerals.
Diet, nutrient concentration, nutritional status, health, and life-stage.
Sodium
•Function - Helps maintain normal fluid and electrolyte balance. Also maintain acid-base balance and is essential to nerve impulse transmission and muscle contraction.
•Deficiency symptoms- Headache, confusion, and seizures..
•Toxicity symptoms- hypertension and heart disease.
•Significant sources- Table salt, soy sauce, and processed foods
Potassium
•Functions- Same functions as sodium.
•Deficiency symptoms- Irregular heatbeat, muscular weakness, glucose intolerance.
•Toxicity symptoms- Muscular weakness; vomiting; if injected into a vein, can stop the heart.
•Significant sources- All whole foods: meats, milks, fruits, vegetables, grains, legumes.
Calcium
•Functions- Mineralization of bones and teeth; involved in muscle contraction and relaxation, nerve functioning, blood clotting, blood pressure.
Deficiency symptoms- Stunted growth in children; bone loss (osteoporosis) in adults.
Toxicity symptoms- Constipation; increased risk of urinary stone formation and kidney dysfunction, interference with absorption of other minerals.
Significant Sources- Milk and milk products, small fish (with bones), calcium-set tofu, leafy greens (broccoli, kale).
Phosphorus
•Functions- Part of genetic material in phospholipids; used in energy transfer and in buffer systems that maintain acid-base balance.
Deficiency symptoms- Muscular weakness, bone pain.
Toxicity symptom- Calcification of nonskeletal tissues, particularly the kidneys.
Significant Sources- Protein-rich foods (meat, fish, poultry, eggs, milk, legumes, nuts).
Magnesium
•Functions- Bone mineralization; participates in energy metabolism and muscle contraction.
•Deficiency symptoms- Muscle cramps, tetany, seizures.
•Toxicity symptoms- From nonfood sources only; diarrhea, nausea, abdominal cramps; metabolic alkalosis.
•Significant sources- Nuts, legumes, green leafy vegetables, some fish.
Compare the roles of minerals in the development of healthy bone tissue and osteoporosis.
Inadequate intake of nutrients important to bone increases the risk for bone loss and subsequent osteoporosis.
Factors that reduce the risk of osteoporosis
Eat calcium-rich foods, absorb enough vitamin D, avoid smoking, and limit alcohol consumption.
Factors that increase risk for osteoporosis
Lack of calcium and vitamin D, menopause, smoking, alcohol, and low physical activity.
Describe nutrition and lifestyle strategies that would reduce your risk for osteoporosis.)
Some nutrition and lifestyle strategies that would reduce the risk of osteoporosis are being more physically active, consuming more vitamin D and calcium rich foods, and to not consume alcohol or smoke.
What enzyme is released from the kidney in response to hypotension?
Renin
What is the source of the most sodium consumed in the American diet?
Processed foods
Which of the following foods contains phytates?
Legumes
Which of the following is a result of hypercalcemia?
Secretion of calcitonin from the thyroid gland
What percentage of bone loss might occur in the six to eight-year period following menopause?
20 percent
At what age does trabecular bone loss become significant for both men and women?
30s
