Minerals Flashcards
What 3 things is H2O balance regulated by?
- Antidiuretic
- Angiotensin II
- Aldosterone
What is antidiuretic hormone secreted in response to?
decrease blood pressure and blood volume, increase salt concentration of extracellular fluids
How does antidiuretic increase blood volume and pressure?
Stimulates thirst, kidneys reabsorb water, promotes vasoconstriction
What does angiotensin II do?
- activated by renin
- Increases blood volume and pressure by vasoconstriction, stimulating thirst and stimulating release of aldosterone
Why is the enzyme renin released?
cells in kidney detect high sodium concentration in the blood
What is aldosterone?
- Released in response to stimulation by angiotensin II when blood volume and pressure are low
- increases blood volume and pressure by increasing sodium retention in kidneys, increase h2o reabsorption (osmosis)
What are the functions of wateR?
solvent, environment for chem rxns, hydrolysis/dehydration, primary constituent of blood, protection, regulate body temp
What is dehydration?
decrease in blood volume, impairing nutrient delivery and waste removal
What are the early symptoms of dehydration?
thirst, headache, fatigue, loss of appetite, dry eyes/mouth, diarrhea
What are the late symptoms?
nausea, difficulty concentrating, confusion, disorientation, collapse. loss of more than 10-20% may result in death
What can water intoxication lead to?
Hyponaturemia: too much h2o in relation to sodium in body causes a drop in sodium concentration
Symptoms of water intoxication?
- water moves into tissues causing swelling
- disorientation, convulsion, nausea, muscle cramps, slurred speech, confusion
Which diets need more h2O?
Low calorie diets: more water to excrete wastes from fat and protein
High fibre, high salt diets
What are the requirements for major and minor minerals?
Major >100mg/day
Minor <100mg/day
What are some factors that affect mineral absorption?
source, what else is eaten at the same time, preparation, varies on the person, easier to absorb minerals from animals
What are the 3 electrolyte minerals?
Na, K, Cl
What are electrolytes?
charged ions responsible for electrical activity in body, regulate fluid balance, can be lost be excessive sweating, diarrhea and vomiting
Sodium
Main +ve extracellular ion
involved in nerve transmission, muscle contraction, fluid balance
Sodium deficiencies?
hyponaturemia: muscle cramps, mental apathy, loss of appetite, confusion
Potassium
main +ve intracellular ion
involved in nerve transmission, muscle contraction, fluid balance (same as sodium but opposite direction)
Potassium deficiencies?
- hypokalcemia
- acutely can lead to irregular heart beat, fatigue, muscle cramps, confusion
- chronically increase risk of hypertension
Potassium toxicity?
irregular heartbeat
Chloride
major -ve extracellular ion. unlikely to have deficiency or toxicity
What is bone
composed of protein matrix hardened by mineral deposits. involves 3 cell types.
What are the 3 cell types in bones?
osteoclasts, osteoblasts, osteocytes
What are osteoclasts?
bone breaking cells
What are osteoblasts?
Bone building cells (immature cells)
What are osteocytes?
what osteoblasts become when incorporated into bone
How to avoid osteoporosis?
- Increase: weight bearing exercise, calcium, vitamin D, zinc, Mg, K, fibre, Na, protein, estrogen
- avoid: smoking, low BMI, alcohol abuse
Calcium
Involved in nerve signalling, heart/muscle contraction, glandular secretions. 99% stored in bones. Body can take it from bone if needed
How is calcium regulated?
- drop in blood Ca increase parathyroid hormone release which stimulates and increase in osteoclasts activity to release Ca from bones, increase activity of vitamin D (Ca absorption at kidneys)
- Increase in blood Ca. increase in calcitonin release which works on bones to inhibit Ca release into blood
What are the calcium needs?
19-50yrs: 1000mg/day. may need to increase after 50yrs
Phosphorous
combined with Ca forms hydroxyapatite crystals of bones and teeth
-Buffers pH, part of DNA, RNA, phospholipids & some proteins, assists in energy metabolism(ATP), activation and deactivation of enzymes through phosphorylation rxns
Magnesium
-regulates Ca homeostasis, needed for Vit D, PTH activity, helps regulate blood pressure
Deficiency Symptoms of Magnesium?
Rare; nausea, muscle weakness, mental derangement, changes in blood pressure
Toxicity of Magnesium
nausea, vomit, low blood pressure
What are the trace minerals?
iron, copper, zinc, selenium, iodine, chromium, fluoride, manganese, molybdenum…
Iron
part of hemoglobin & myoglobin (muscles); crucial for O2 transport, part of iron containing proteins in electron transport chain
What is hemeiron?
part of heme/myoglobin, from animal sources, 2x better absorbed
What is non-heme iron?
From plant sources, harder to absorb, absorption improved when eaten with sources of heme iron; vitamin C
Deficiencies of Iron?
anemia (pale small RBC), fatigue, weakness, headache, behaviour changes, poor temp regulation
Iron toxicity?
Hemochromatosis (build up over time), weight loss, fatigue, weakness, abdominal pain
can damage heart, liver, increase risk of diabetes, cancer
Copper
Involved in: connective tissue synthesis, lipid metabolism, heart muscle maintenance, part of antioxidant superoxidedismutase
Deficiency of Copper?
improper collagen synthesis, impaired growth, elevated blood cholesterol, increase risk of infection, can also lead to iron-deficiency anemia because copper containing protein is required for iron absoption
What are the many roles of zinc?
-Crucial in gene expression, part of antioxidant zinc superoxidedismutase, needed to maintain concentration of metal binding proteins, DNA/RNA synthesis, carb metabolism, acid/base balance, storage/release of insulin, mobilizes vitamin A from liver, stabilizes cell membranes, hormonal regulation of cell division, growth/repair of tissues, immune system, sex organs
Zinc deficiency?
Rare in North America; impairs growth, immune system, causes skin rash, diarrhea
Zinc toxicity?
Digestive tract irritation, vomiting, loss of appetite, diarrhea, abdominal cramps, can interfere with iron absorption
Selenium
Incorporated into structure of some proteins
Selenium Deficiency?
Can lead to keshans disease, risk of cancer
Iodine
Part of thyroid hormone; regulate metabolic rate
Iodine Deficiency
can’t synthesize enough thyroid hormone
- slower metabolic rate, fatigue, weight gain, can lead to goitre (thyroid gland tries to synthesize enough but can’t so it enlarges)
- can lead to cretinism; irreversible, inadequate maternal levels during pregnancy, impairs mental function, growth
Chromium
key component of glucose tolerance factor, required to maintain normal blood glucose levels
Fluoride
helps prevent dental caries > part of fluropatite > makes up tooth enamel
Manganese
Part of some enzymes & activates others, involved in card/cholesterol metabolism, bone formation, synthesis of urea, superoxidedismutase
Molybdenum
also needed to activate enzymes, metabolism of sulfur containing amino acids, nitrogen containing compounds in DNA/RNA, production of uric acid, oxidation & detoxification
