Chapter 25 Diseases of the Musculoskeletal System) Flashcards
Diseases of the Musculoskeletal System
What are metabolically active cells and tissue that are reserved for calcium and phosphorus?
- cartilage, ligaments, tendons, bones
- which, are in a continual state of change
What are osseous tissue?
- bone (inorganic and organic)
What is inorganic osseous tissue?
- hydroxyapatite (component of bone tissue, crystallite)
- stiffness, weight bearing
What is organic osseous tissue?
- mainly collagen
- flexibility
What are the two calcium reserves that bone provide?
- Hydroxyapatite (99%): massive, but less readily accessible
- 1% readily available pool, which is in our blood
What are the bone abnormalities in serum calcium critical?
- hypocalcemia (excessive excitability of the nervous system, tetany, respiratory arrest, convulsions)
- hypercalcemia (fatigue, depression, mental confusion, anorexia, nausea, vomiting, constipation, hypercalciuria)
What are the four types of cells found in osseous tissue?
- osteogenic cells
- osteoblasts
- osteocytes
- osteoclasts
What are osteogenic cells?
- stem cells that differentiate into osteoblasts
What are osteoblasts?
- bone building cells
- lay down new bone in high stress areas
What are osteocytes?
- mature osteoblasts, majority of cells in bone
What are osteoclasts?
- bone removing cells that secrete HCL to dissolve mineral component of bone matrix; bone resorption; regulate bone levels
- remove bone from low stress areas
What is skeletal growth and developement?
- continual state of change; linear and circumferential growth, remodeling
What is cortical bone?
- dense, outer surface of most bones
- shafts of long bones
- caps over end of long bones
What is trabecular bone?
- loosely organized with a sponge-like apperance; lattice like pattern
- found at the “ends” of long bones, primary bone of vertebrae, pelvis, sternum, scapula
What keeps calcium and phosphorous at homeostasis in the hormonal control of bone metabolism?
- cortisol (steroid hormone for break down of bone), growth hormone, thyroid hormones
What are the primary regulators for calcium and phosphorous homeostasis?
- parathyroid hormone (PTH)
- calcitonin
- vitamin D
What does the parathyroid hormone (PTH) do in the hormonal control of bone metabolism?
- increases blood calcium when low
How does the parathyroid hormone (PTH) increase the blood calcium when low in the hormonal control of bone metabolism?
- increase in osteoclasts, and bone resorption
- inhibition of collagen synthesis, and bone deposition
- calcium resorption by kidneys
- needs help in final step from vitamin D, enhancing intestinal absorption of calcium
What does calcitonin do in hormonal control of bone metabolism?
- decreases blood calcium when high
How does calcitonin decrease blood calcium when high?
- inhibits activity of osteoclasts
- stimulates osteoblasts
- reducing renal reabsorption of calcium and phosphate
What does vitamin D do for the hormonal control of bone metabolism?
- increases blood concentrations of calcium and phosphorous
How does vitamin D increase blood concentration of calcium and phosphorous in hormonal control of bone metabolism?
- promotes their absorption in GI
- promotes reabsorption by kidneys
- stimulates osteoclast formation and release of calcium and phosphorous from bone
What are the two types of Vitamin D?
- ergocalciferol (vit. D2) - dietary (fatty fish, milk, fortified foods, cereal, mushrooms)
- cholecalciferol (vit. D3) - dietary and exposure to sunlight
Both ergocalciferol and cholecalciferol are biologically inactive until?
- modified by liver and kidney to 1-25 dihydroxyvitamin D
What is osteoporosis?
- decreased bone mineral and organic matrix which weakens bones, making them more susceptible to fracture and pain
What does bone strength reflect?
- bone density (measured by dexascan)
- bone quality (harder to measure; by fractures)
True or False? Hip fractures increases mortality and morbidity among persons 65 yrs. of age or older.
- True
When does bone mineral density (BMD) rapidly increase?
- during the growth spurt (ages 11 - 14)
When does bone mineral density reach its max?
- in late 20’s and 30’s
- has to maintain from here
Who loses bone mineral density faster, men or women?
- women
- rate of loss increases during menopause
What are the primary etiology of osteoporosis?
- disease of elderly
- cumulative impact of bone mineral loss
- deterioration of bone with age
- “age related”, “postmenopausal”
What are the secondary etiology of osteoporosis?
- due to other diseases
- associated with drugs (2/3 cases of men)
What is kyphosis?
- unnatural curvature of back
- loss of height due to compression fractures of spine
What are the most common sites of fractures due to osteoporosis?
- hip, spine, wrist
- hip fractures have severe impact on morbidity and mortality (20% die within first year; 20% end up in nursing homes
What are the nutritional risk factors for osteoporosis?
- calcium
- vitamin D
- phosphorous, protein, sodium, caffeine, fluoride, and trace minerals
What maintains serum calcium levels to combat bone resorption?
- calcium
What helps achieve peak bone mass and minimize bone mineral loss?
- calcium
Lower intakes of animal protein, sodium, and caffeine helps prevent?
- osteoporosis
Increased consumption of what helps prevent osteoporosis?
- fruits, vegetables, legumes, and whole grains
- more physical activity
- 10-15 mins./day sun exposure
How would you increase your calcium levels?
- consume calcium rich foods (dairy, bread, cereal, salmon w/ bone, OJ)
- calcium fortified foods
- calcium supplements (calcium carbonate, calcium citrate, calcium with vit. D)
How much calcium can the body absorb at once?
- 500mg
Overt deficiency of vitamin D causes what?
- rickets in children
- osteomalacia in adults (insufficiency found in dark skin, older, in northern latitudes
What is essential for bone formation, but Americans get too much of?
- phosphorus
- found in a lot of animal meats
- found in soft drinks, which can contribute to bone loss
What interferes with Ca+ absorption and cause bone loss?
- caffeine and phytates (food components found in spinach, beans, and wheat bran)
- more than 3 cups/day (24oz) of coffee
Calcium can’t be absorbed well from foods high in what?
- oxalates (found in spinach, rhubarb, beet greens, and some beans
What increases urinary calcium losses?
- high protein or sodium
What foods/minerals are associated with higher bone mineral density?
- potassium, magnesium, fruits, and vegetables
Cigarette smoking is causally related to what when talking about osteoporosis?
- lower bone density
- increased bone mineral loss
- increased risk of fracture in males and females
What is toxic to osteoblasts?
- nicotine and cadmium
Nicotine reduces and lowers what, when talking about osteoporosis?
- reduces intestinal calcium absorption
- lowers intake of vitamin D, and lower serum vitamin D
What kind of physical activity improves osteoporosis?
- weight bearing
- impact type
Osteoporosis is commonly found in who?
- chronic alcoholism
Moderate alcohol consumption may increase what and reduce what only in women?
- increase BMD
- reduce bone mineral loss
What adversely impacts vitamin D and overall nutritional status?
- alcohol
What increases calcium and magnesium losses?
- alcohol
What are the pathophysiology of osteoporosis?
- failure to build bone and reach peak bone mass as a young adult. (late 20’s N 30’s)
- bone loss later in life (modifiable N unmodifiable risk factors)
What accounts for up to 80% of the variance in peak bone mass?
- genetics
- RANK/RANKL/OPG signaling pathway is essential for development of osteoclasts.
How would you conclude osteoporosis as the medical diagnosis?
- measure bone density (w/ DXA scan)
- occurrence of adulthood hip or vertebral fracture in absence of trauma
- quantitative ultrasound of the heel (in conjunction w/ risk assessment
- PQCT
How is bone mineral density (BMD) measured?
- DXA (dual-energy x-ray absorptiometry
- “T-score” (comparing patients BMD to healthy young reference population
- at hip and lumbar spine
- see WHO criteria
What is osteopenia?
- low bone mineral density, but, not low enough to be classified as osteoporosis, although fracture risk is increased
What is the treatment for osteoporosis?
- adequate intake of calcium and vitamin D
- physical activity and fall prevention (weight bearing exercise)
- smoking cessation
- avoidance of excessive alcohol intake
- depends on disease or problem to asses and treat
What are the medical management of osteoporosis?
- risk factor modification
- dietary treatment
- drug therapy (to prevent further loss)
What is the normal value of serum calcium?
- 9-10.5 mg/dL (does not reflect dietary intake)
What is the formula to “correct” calcium levels if low albumin?
- (normal alb. - observed alb.) x 0.8 + serum calcium =
- use 4.0 for normal albumin
what are the pharmacologic prevention and treatment for osteoporosis?
- estrogens/hormone therapy (can cause breast cancer)
- selective estrogen receptor modulators (SERMs)
- bisphosphonates (tells osteoclasts to stop)
- teriparatide (synthetic PTH)
- drug-nutrient interactions
What is the nutritional diagnosis for osteoporosis?
- inadequate vit. D and/or calcium intake
- physical inactivity
- food and nutrition related knowledge deficit
- altered GI functions (ex. celiac)
- predicted food-medication interaction
- malnutrition
- excessive alcohol intake
what is the nutrition intervention for osteoporosis?
- depends on etiology of nutrition diagnosis
- includes educational component
- may include referral to smoking/alcohol cessation program
- calcium supplements
how would you monitor and evaluate the nutrition intervention of osteoporosis?
- reassessment of calcium and vitamin D intakes
- tolerance or consistency to supplements
- 25 (OH) vitamin D3 labs
- amount and type of exercise
What is Paget disease?
- localized, progressive, crippling disorder of bone remodeling d/t overactive osteoclasts and bone resorption followed by rapid formation of new bone which is structurally inferior
What is Paget disease caused by?
- genetics and viral factors
what results from the Paget disease?
- bowing, deformity, fracture, poor healing
where in the body is the Paget disease most affecting?
- upper femur, pelvis vertebral bodies, skull, tibia
which nutrients are most important to take in if you have Paget disease?
- vitamin D and calcium
What is rickets?
- kinda like osteoporosis in children
- inadequate maturation and mineralization of bone d/t vitamin D deficiency
when is rickets first seen in a child?
- about 36 months or when the child starts to walk
what are the symptoms of rickets?
- lethargy
- weakness
- growth stunting
- enlargement of ends of long bones and ribs
- abnormally shaped thorax
- bowing of legs
what are the risk factors for rickets?
- maternal vit D deficiency
- prolonged breastfeeding without vit D supplementation
- living in a temperate climate
- lack of sunshine
- dark skin pigmentation
- calcium deficiency
- intake of phytates from diets high in unrefined grains
How can you prevent rickets?
- exclusively breast fed infants should receive supplement of 400 IU vit D
- fortified infant formulas (if fed <500ml/day, take multivitamin)
- after one year switch to vit D fortified cows milk
what is the treatment for rickets?
- balanced age-appropriate diet
- adequate vit D, calcium, phosphorus
- posture
what is Osteomalacia?
- adult form of rickets
- organic matrix of bones inadequately mineralized in adults
what results from Osteomalacia?
- muscular weakness
- bone pain
- deformities of ribs, pelvis, legs
what is the etiology of Osteomalacia?
- due to vit D deficiency
- impaired D action
- calcium deficiency
- hypophosphatemia
what is the treatment for Osteomalacia and rickets?
- address underlying cause
- multivitamin supplementation
- calcium supplementation
- pharmacological doses of vit D
where in the body does arthritic conditions affect?
- affect joints
- tissues surrounding joints
- connective tissues
name some common arthritic conditions?
- Osteoarthritis
- Rheumatoid arthritis
- Gout (affects all ages)
Who are affected with arthritic conditions?
- one in five Americans
- one in four reports activity limitations
what are the modifiable and non-modifiable risk factors for arthritic conditions?
modifiable: overweight (most common), joint injuries, infections
non-modifiable: family history, female sex, age
what is Osteoarthritis?
- disease process involving all structures of the joint
- loss of load-bearing articular cartilage
- inflammation
- joint pain, stiffness, limited movement
- wasting of periarticular muscles
- joint instability and deformity
what are the major risk factors of osteoarthritis?
- age
- female sex
- family history
- major trauma to joint or soft tissue
- repetitive joint stress related to occupation
- obesity
what are the treatments for osteoarthritis?
- reduce joint inflammation, pain, maintain mobility, minimize disability
- improve body posture
- proper footwear
- weight reduction
- periodic rest of affected joint
- heat and cold compresses
- physical activity/therapeutic exercise
- drug therapy - pain relief (NSAIDs, Glucosamine, Chondroitin)
What is Rheumatoid arthritis?
- chronic inflammatory disease
what gets inflamed when dealing with rheumatoid arthritis?
- synovial membrane
what results from the synovial membrane inflammation in rheumatoid arthritis?
- swelling, stiffness, pain, limited range of motion, joint deformity, disability
- periods of exacerbation and remission
- autoimmune response
which part of the body is rheumatoid arthritis most affects?
- joints of hands, wrists, knees, feet
When inflammation results in thickening of the synovial membrane, it is called?
- Pannus
why is pannus, thickening of synovial membrane, bad?
- enzymes from pannus digest adjacent bone and cartilage
what is the treatment for rheumatoid arthritis?
- reduce pain and inflammation
- protect joint
- maintain function
- control systemic infections
- pharmacological agents: NSAIDs, glucocorticoids, immunosuppressives, DMARDs
what is the nutritional intervention for rheumatoid arthritis?
- increase consumption of fruits and vegetables/antioxidants
- include sources of EPA and DHA (fish oils) (omega-3)
- fish oil supplementation
- exclusion of red meats, dairy, cereals, wheat gluten
- evaluate and test for food allergy
What is Gout, arthritic condition?
- inflammatory disease resulting in swelling, redness, heat, pain, and stiffness in affected joint
what is the most painful arthritic condition?
- Gout
- most common in men
what is the etiology of Gout?
- elevated serum concentrations of uric acid, formation of uric acid crystals
what is hyperuricemia?
- high levels of serum uric acid
what causes elevation of serum uric acid, hyperuricemia?
- results from overproduction of uric acid
- inadequate elimination of uric acid by the kidneys
- or combination of both
what is the clinical manifestation of Gout?
- symptoms usually develop rapidly, resulting is sudden, severe joint pain and swelling along with shiny, red skin and extreme tenderness around joint
- typically resolves in 5-10 days, may reoccur
what would acute attacks of Gout be from?
- excessive exercise
- certain medications; aspirin, diuretics, nicotinic acid, cyclosporine, levodopa
- purine rich foods (anchovies, sardines, fish roe, organ meats, nutritional yeast)
- excessive alcohol consumption
- crash dieting
what is the treatment of Gout?
- NSAIDs, glucocorticoids, colchicine (anti-inflammatory)
- treat uricemia
- lifestyle modifications
