Flashcards in Chapter 12: Nutrients Involved in Bone Health Deck (29)
What're the two types of bone? What're their functions/where can they be found?
1) cortical bone: More compact bone that makes up the outer surface of all bones, 80% of all bone makes up the wrists and fingers and toes.
2) trabecular bone; spongy bone, 20% of all bones. ends of the long bones in arms and legs. Faster turn over.
What type of bone tends to regenerate faster?
What's the main component of the protein matrix? How does the protein matrix of bones harden?
main component of protein matrix is collagen. hardened by minerals- aid in bone strength
protein and vitamin C is needed to maintain ____
calcium and minerals is needed to ensure _____ and solidarity
Vitamin D is needed to maintain ____(mineral) supply
protein and vitamin C is needed to maintain collagen
calcium and minerals is needed to ensure strength and solidarity
Vitamin D is needed to maintain calcium and phosphorus(mineral) supply
T/F lifting heavy weights and strength training can make the bones more brittle
false. strength training makes bones stronger
T/F: bone cells are relatively stable with a long lifespan
false. bonds are constantly being broken down and reformed
WHat is an osteoclast? When are they activated?
an osteoclast breaks down bone. Activated when blood calcium gets too low. The osteoclast then breaks down the bone to release more calcium into the blood stream.
What is an osteoblast? when are they activated? where are they located? What do they turn into?
osteoblasts re-form bone. When calcium levels in the blood are adequate, osteoclasts stop breaking down bone and the osteoblasts promote bone density and bone growth. Osteoblasts are incorporated into the bone matrix to mature into OSTEOCYTES, which further promote density.
When one reaches peak bone mass, bone formation (>//
bone formation>bone breakdown
Peak bone mass is usually reached during young adulthood, and is when maximum bone density is attained.
T/F in women, bone loss is accelerated after menopause.
True. due to decreased estrogen levels
What type of technology can determine mineral content and bone mineral density?
Dual XRAY absorptiometry
What type of bone does Bone mineral density (BMD) affect most?
trabecular bone is affected more because it has a higher turn over rate and is more susceptible to bone loss.
_____ is a disorder characterized by decreased BMD, increased bone fragility, active osteoclasts>osteoblasts, and increased risk of fracture.
T/F If a person is calcium deficient, they should consume phytates and tannins
false. tannins and oxalates reduce calcium absorption
T/F if a person is calcium deficient, they should watch their sodium intake
true. if you have too much sodium, your kidneys will filter it out through the urine, causing calcium loss too.
Besides bone health, name three other functions that use calcium
1) nerve transmissions
2) muscle contractions
3) blood pressure regulation
Name the mechanism of what happens when there are decreased levels of blood calcium
decreased blood calcium ---> PTH secretion --> stimulate intestinal Ca2+ absorption, kidney reabsorption, and bone reabsorption (via osteclasts breaking bone down) ---> increased blood calcium
What is PTH
parathyroid hormone : helps increase blood calcium by telling organs to start absorbing more.
What is Calcitonin?
helps to decrease blood calcium by deactivating bone break down and facilitating more calcium excretion
Name the mechanism of what happens when there is too much calcium in the blood
increased blood calcium --> calcitonin secretion ---> inhibits bone reabsorption --> decreased blood vitamin.
What is calcium rigor?
an affect of calcium toxicity that causes the inability for muscles to relax. Calcium toxicity can also lead to kidney stones and impair absorption
Cholecalciferol vs calcitriol?
cholecalciferol is a provitamin and a precursor made from dehydrocholesterol in the skin and sunlight. cholecalciferol forms calcitriol, which si the active form of vitamin D.
Cholecalciferol vs ergocalicerol
cholecalciferol: vitamin D3 precursor
ergocalicerol: vitamin D2 precursor
T/F Vitamin D levels in the body are affected by skin color
true. individuals with darker skin or who wear darker clothes that cover the whole body are at risk for vitamin D deficiencies.
The RD of vitamin D is based on the assumption ____
that no vitamin D is made by the skin
what're the two main functions of vitamin D in the body?
1) regulates blood calcium levels (when blood calcium is low/high, vitamin D and PTH/Calcitonin hormones work together to facilitate proper calcium levels via reabsorption or excretion
2) involved in gene expression
What is rickets and what is it caused by?
rickets is bone malformation in children caused by improper bone mineralization due to Vitamin D deficiencies
T/F people with kidney failure are at risk for a vitamin D deficiency
true, although they can be exposed to sun like anyone else, they lack the mechanism to activate vitamin D.