Chapter 8 - Minerals Flashcards Preview

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Flashcards in Chapter 8 - Minerals Deck (14)
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What 4 elements are living matter composed of - building blocks of life?

- hydrogen
- carbon
- nitrogen
- oxygen


Of the 118 elements on the periodic table, how many are essential to human life




single type of atom
- of 118 elements, 94 occur naturally on earth
- cannot be broken down into smaller substances


major minerals

group of minerals that are required by the body in amount of more than 100 mg/day
- calcium, phosphorus, sodium, potassium, chloride, magnesium, sulfur


key concepts

human body requires a variety of minerals to perform its numbers metabolic tasks
- mixed diet of varied foods and adequate energy value is the best source of minerals necessary for health
- of total amount of minerals that a person consumes, only a relatively limited amount is available to the body


trace minerals

group of elements that are required by the body in amounts of less than 100 mg/day
- iron, iodine, zinc, selenium, fluoride, copper, manganese, chromium, molybdenum, cobalt, boron, vanadium, nickel


mineral metabolism

controlled either at the point of intestinal absorption or at the point of tissue uptake


mineral digestion

absorbed and used in the body in their ionic forms
- carries either a positive or negative electric charge
- do not require a great deal of mechanical or chemical digestion before absorption occurs


mineral absorption

- influencing factors: food form (animal sources more readily absorbed), body need (more absorbed if body if deficient), tissue health (is intestinal surface is diseases, absorptive capacity is diminished)
- presence of fiber, phytate, or oxalate can bind certain minerals in the GI tract and inhibit or limit their absorption


mineral transport

enter the portal blood circulation and travel throughout the body bound to plasma proteins or mineral specific transport proteins (ex: iron binds to transferrin in the circulation)


mineral tissue uptake

controlled by hormones
- excess excreted into the urine


thyroid-stimulating hormone (TSH)

controls the uptake of iodine from the blood by the thyroid gland
- dependent on the amount that the thyroid gland needs to make the hormone thyroxine
- when more is thyroxine is needed, TSH stimulates thyroid gland to take up indie and the kidney to excrete less iodine in the urine
- less TSH is released from the anterior pituitary gland when thyroxine concentration is normal


mineral occurence in the body

- free ions in body fluids (sodium in tissue fluids which influence water balance)
- covalently bound minerals that may combine with other minerals (calcium and phosphorus in hydroxyapatite) or organic substances (iron bound to heme and global to form organic compound hemoglobin)



2% of total body weight is calcium (most are bones & teeth = 99% / 1% body weight)