Musculoskeletal Flashcards
These cells are actually a syncytium of macrophages
Osteoclasts
Remember that macrophages eat things, so it would make sense for osteoclasts to be made of macrophages
This type of bone is compact bone
cortical bone
The ringed system of the bones is called the
haversian system
Where is the epiphyseal plate located?
Between the epiphysis and the diaphysis (the plate is responsible for the growth of long bones)
What is osteomalacia?
Softening of the bones due to demineralization (if this occurs in growing bones, it’s called rickets)
(the bones become Malleable)
What is a sprain?
Joint injury caused by twisting of the joint.
Does osteoporosis cause cord damage?
NO. It only causes crush fractures of the spine- leading to kyphosis
Kyphosis is often the result of
compression fractures
What happens in osteoporosis?
Compact (cortical) bone becomes thinner, and trabecular bone becomes thinner and more porous.
What is the medulla of the bone?
The part that contains the marrow
How often does bone get completely overturned?
Every 7 years
Why is osteoporosis less common in men?
1) They start out with thicker bones
2 They don’t go through menopause (we lose bone at a smaller rate)
3) The cortex and medulla both grow at the same rate
4) Men die at a younger age
How do we prevent osteoporosis?
Take vitamin D and dietary calcium!
What is osteomyelitis?
Infection of the bone itself
These cancers are known to metastasize to the bone
Breast and prostate
Why are primary bone cancers uncommon?
No cancers of osteoclasts, because these are actually syncytiums of macrophages. Osteoclasts do not replicate.
Other bone cells grow VERY VERY slowly, so are not a hot spot for developing CA.
How likely is cancer of a tendon?
VERY unlikely. No blood supply here.
These are all examples of non-inflammatory joint diseases
Osteoarthritis
Sprain
Dislocation
Traumatic injuries
These are all examples of inflammatory joint diseases
Rheumatoid arthritis (2nd most common arthritis) Gouty arthritis Infectious arthritis (Lyme disease)
Why does osteoarthritis happen more commonly in athletes?
1) More wear and tear
2) Recurrent injuries cause bones to be slightly offset, which causes the joint to wear down more quickly
These supplements can help prevent osteoarthritis
Glucosamine and chondroitin
Why don’t glucosamine and chondroitin help arthritis once it’s already there?
Because chondrocytes need these factors to make ECM. However, if the cartilage is already eroded away, there are no chondrocytes left to use these materials and create ECM.
These joints are the most affected by osteoarthritis
Hips and knees *** (think about how many replacements are done for these!)
The back is also pretty common (lower lumbar)
Other common sites: hands and feet)
Cause of rheumatoid arthritis
Autoimmune diseases that attacks the joint AND surrounding bone. Can be treated with immuno-modulators.
How does gout occur?
The blood is supersaturated with uric acid from several causes
1) High protein diet
2) Increased synthesis of purines (which can happen in anemia or leukemia-> either increased from increased RBC breakdown and we need to make more RBCs or from rapid cell and DNA synthesis in cancer)
3) Renal problems (decreased filtration of uric acid)
The uric acid will start to precipitate in locations that are cooler than the rest of the body, like the big toe. Uric acid crystals form in the joint (called white tophi), and cause extreme pain. The person will often think they broke their toe.
Macrophages infiltrate the area, try to eat the uric acid crystal, but fail and die. This attracts more inflammatory cells causing continuous inflammation and accumulation of dead cells.
How is gout diagnosed?
Synovial fluid sample
What function does uric acid normally serve in our blood?
Antioxidant
Club foot is also called
Talipes equinovarus
What is the frequent cause of talipes equinovarus?
Oligohydramnios. Most will be fixed with physical therapy! If no, fixed by surgery.
Cause of osteogenesis imperfecta (brittle bone disease)
A defect in Collagen I (the collagen is imperfect!
Our bones will be strong for compression, but weak under torsion.
What does collagen normally do for our bones?
Serve as rebar, allowing our bones to be strong under torsion.
Treatment for osteogenesis imperfecta
Telescoped rods in the long bones.
Cause of rickets
Lack of Vitamin D prevents proper bone mineralization. This results in weak bones that bend easily. They don’t break, just become bendy and they get crooked legs.
What is osteomalacia?
Same thing as rickets, but occurs in adults. Usually a more mild form of the disease. Caused by a lack of vitamin D resulting in soft bones.
Example of a fast-twitch dominant muscle
Latissimus dorsi (can do a few pull-ups, but not a hundred)
Example of a slow-twitch dominant muscle
The tongue
