week 12 bone health Flashcards
(30 cards)
What are the two main types of bones?
Cortical (compact) and Trabecular (spongy)
Cortical bones are dense and provide strength, while trabecular bones are less dense and respond to hormones.
What percentage of bone composition is inorganic matter?
65%–>mineral crystals deposited into collagen
Inorganic matter consists of mineral crystals deposited into collagen.
What is the role of organic matter in bones?
Allows flexibility to bones
Organic matter is primarily collagen, which is crucial for absorbing stress.
Define bone mineral density.
A measure of how tightly mineral crystals are packed into the protein matrix
It is an indicator of bone strength.
What is osteoporosis?
A disease caused by excessive loss of bone resulting in porous and fragile bones
This condition increases the risk of fractures and breaks.
What are osteoclasts?
Cells in the bone that break down bone during growth
They are responsible for bone resorption.
What lifestyle factors influence bone health?
Nutrition, weight-bearing exercises, alcohol intake, smoking, stress, sleep, body weight
Adequate intake of vitamin D, calcium, and protein is essential.
What is the most abundant mineral in the body?
Calcium
99% of calcium is stored in bones and teeth.
What is the function of calcium in the body?
Maintains normal blood pressure, participates in blood clotting, binds to proteins for muscle contractions
Calcium also plays a role in nerve impulses and hormonal secretion.
What happens when blood calcium levels are low?
Parathyroid gland secretes parathyroid hormone
This hormone stimulates the activation of vitamin D and calcium reabsorption.
Fill in the blank: Adults absorb approximately ______ of calcium digested.
30%
Absorption can be higher in pregnant women and children.
What are the recommended dietary allowances (RDA) for calcium in adults aged 19-50?
1000 mg/day
Higher recommendations exist for older adults and adolescents.
What is the RDA for phosphorus? what is the UL?
RDA:700 mg/day
UL: 4000 mg/day
Phosphorus is combined with calcium in bones.
How is vitamin D synthesized in the body?
With the help of sunlight which transforms 7-dehydrocholesterol in the skin
The liver and kidneys convert it to active vitamin D.
What is the recommended daily allowance (RDA) for vitamin D in adults aged 19-70?
600 IU/day (15ug/day)
The RDA increases to 800 IU/day for adults over 70.
What condition results from vitamin D deficiency in adults?
Osteomalacia
This condition leads to soft, flexible, and brittle bones.
What impact does magnesium have on muscle function?
Calcium promotes muscle contraction while magnesium inhibits it
This balance is crucial for muscle relaxation.
What is the function of fluoride in bone health?
Replaces hydroxyl in hydroxyapatite to form fluorapatite
Fluorapatite strengthens bones and teeth.
What is the role of vitamin K in bone health?
Metabolism of bone proteins, specifically osteocalcin
Adequate vitamin K intake decreases bone turnover and protects against fractures.
What is the toxicity associated with excess vitamin D?
Can raise blood calcium concentration leading to kidney stones
It may also harden blood vessels affecting major arteries.
what percentage of bone matter is organic?
35% –> collagen
what is osteoblasts
cells in the bone that rebuild bone during growth
what is the RDA for calcium for men 51-70 yrs old?
1000mg/day
what is the RDA for calcium for men 71 yrs and older
1200mg/day
