Chapter 8 Flashcards
(31 cards)
What are minerals?
No living organism synthesizes minerals. Minerals come from the earth and are indestructible.
Minerals are elements.
What are the major and trace mineral requirements?
Major minerals: >100mg/ day
Trace minerals: <100mg/ day
What are the compartmental Body Fluid types?
(1) Intracellular Fluid: Fluid inside the cells. Some minerals populate it.
(2) Extracellular Fluid: Fluid located outside a cell
What are the sources of minerals?
Food and tap water
What is Hard vs soft water?
which is better?
(1) “Hard” water has a high concentration of calcium and magnesium
(2) “Soft” water – treated with sodium or potassium
Water hardness varies on regions. Areas with harder water may reduce hypertension while softer water does increases it
Where is calcium (mineral) stored?
what happens if blood calcium levels drop?
Over 99% of calcium is found in bones and teeth (<1% in blood
calcium in bones also acts as reservoir for when blood calcium levels drop
Why are blood calcium levels important?
Explain the process
Neurons rely on steady supply of blood calcium to communicate with neighboring neurons
Electrical signals open protein channels for calcium to flood in presynaptic neuron
What is calcium homeostasis?
Bones are continuously remodeled:
(1) Osteoclasts: degrade bone tissue
(2) Osteoblasts: build bone tissue
When blood calcium levels drop, bone is demineralized to liberate calcium into blood. As we age, activity of osteoblast cells declines but osteoclast cells continue → bone loss
What is the thyroid gland?
Butterfly shaped. Wrapped around the trachea.
Hormones synthesized by cells of the thyroid gland are deposited inside the blood vessels that can then circulate anywhere in the body.
What are the parathyroid glands?
Located behind the thyroid gland are 4 smaller glands. These synthesize hormones that are released into the blood
Explain the steps in falling blood calcium levels?
(1) Parathyroid glands produce and secrete the parathyroid hormone PTH
(2) Parathyroid hormone circulates in blood.
(3) Kidneys respond to PTH in the blood by activating the stored vitamin D.
(4) Active vitamin D and PTH duo decrease the amount of calcium excreted in urine.
(5) Vitamin D travels to small intestine and increases the bioavailability of calcium.
(6) More calcium absorbed in the small intestine, blood calcium levels rise.
(7) PTH-vitamin D duo signal osteoclasts to release calcium from bones → less calcium lost in urine, bioavailability of calcium increases, bones are demineralized to release calcium.
What are the bioavailability of calcium in Spinach, Broccoli, Dairy (milk)?
Spinach: High in Calcium, but also with oxalates (binds w/ calcium and prevent absorption). 14mg/ serving
Broccoli: Less Calcium. Bioavailability is high. 30mg/ serving
Dairy (Milk): High Calcium, high bioavailability. 96mg/ serving
What is sodium effect on Calcium?
Excess salt intake forces the kidneys to increase urine production in an effort to eliminate excess sodium. Consequently, calcium is also lost.
When do you achieve peak bone mass? What is it?
Highest attainable bone density achieved in the first 3 decades of someone’s life
Where do we find phosphorus in our diet
Nearly everything we eat
Where in the body do we find magnesium?
Over 50% in bones, 27% in muscle cells, 7% in other cells
What foods are a good source of Magnesium?
Deep green leafy vegetables and legumes
How does sodium influence neural communication?
Critical in propagating the electrical impulse down the body of a neuron
What is sodium’s role in fluid balance?
High intake is associated with hypertension (chronically elevated blood pressure and CVD)
Where is Poatassium found in real food
Found in real food - processed lose their potassium because cells are no longer intact
Where is iron found in the body?
Over 60% in red blood cells. In heme
What is Iron’s role regarding blood health?
Oxygen crosses the epithelial cells of the lungs and enters the blood capillaries. Oxygen enters the RBC and binds to the iron.
Too little or too much iron is just as deadly
What is heme iron vs. nonheme iron
heme iron: found in animal products
nonheme iron: found in plants (90% of iron intake)
What is iron-deficient anemia (steps)?
Most common nutrient deficiency
Severe depletion of iron stores that result in a low hemoglobin concentration → RBC are smaller and more pale→ work harder to circulate oxygen-poor blood → heart is overworked and enlarges → heart failure
