Musculoskeletal

Question 1

These cells are actually a syncytium of macrophages

Answer 1

Osteoclasts

Remember that macrophages eat things, so it would make sense for osteoclasts to be made of macrophages

Question 2

This type of bone is compact bone

Answer 2

cortical bone

Question 3

The ringed system of the bones is called the

Answer 3

haversian system

Question 4

Where is the epiphyseal plate located?

Answer 4

Between the epiphysis and the diaphysis (the plate is responsible for the growth of long bones)

Question 5

What is osteomalacia?

Answer 5

Softening of the bones due to demineralization (if this occurs in growing bones, it’s called rickets)
(the bones become Malleable)

Question 6

What is a sprain?

Answer 6

Joint injury caused by twisting of the joint.

Question 7

Does osteoporosis cause cord damage?

Answer 7

NO. It only causes crush fractures of the spine- leading to kyphosis

Question 8

Kyphosis is often the result of

Answer 8

compression fractures

Question 9

What happens in osteoporosis?

Answer 9

Compact (cortical) bone becomes thinner, and trabecular bone becomes thinner and more porous.

Question 10

What is the medulla of the bone?

Answer 10

The part that contains the marrow

Question 11

How often does bone get completely overturned?

Answer 11

Every 7 years

Question 12

Why is osteoporosis less common in men?

Answer 12

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

Question 13

How do we prevent osteoporosis?

Answer 13

Take vitamin D and dietary calcium!

Question 14

What is osteomyelitis?

Answer 14

Infection of the bone itself

Question 15

These cancers are known to metastasize to the bone

Answer 15

Breast and prostate

Question 16

Why are primary bone cancers uncommon?

Answer 16

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.

Question 17

How likely is cancer of a tendon?

Answer 17

VERY unlikely. No blood supply here.

Question 18

These are all examples of non-inflammatory joint diseases

Answer 18

Osteoarthritis
Sprain
Dislocation
Traumatic injuries

Question 19

These are all examples of inflammatory joint diseases

Answer 19

Rheumatoid arthritis (2nd most common arthritis)
Gouty arthritis
Infectious arthritis (Lyme disease)

Question 20

Why does osteoarthritis happen more commonly in athletes?

Answer 20

1) More wear and tear

2) Recurrent injuries cause bones to be slightly offset, which causes the joint to wear down more quickly

Question 21

These supplements can help prevent osteoarthritis

Answer 21

Glucosamine and chondroitin

Question 22

Why don’t glucosamine and chondroitin help arthritis once it’s already there?

Answer 22

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.

Question 23

These joints are the most affected by osteoarthritis

Answer 23

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)

Question 24

Cause of rheumatoid arthritis

Answer 24

Autoimmune diseases that attacks the joint AND surrounding bone. Can be treated with immuno-modulators.

Question 25

How does gout occur?

Answer 25

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.

Question 26

How is gout diagnosed?

Answer 26

Synovial fluid sample

Question 27

What function does uric acid normally serve in our blood?

Answer 27

Antioxidant

Question 28

Club foot is also called

Answer 28

Talipes equinovarus

Question 29

What is the frequent cause of talipes equinovarus?

Answer 29

Oligohydramnios. Most will be fixed with physical therapy! If no, fixed by surgery.

Question 30

Cause of osteogenesis imperfecta (brittle bone disease)

Answer 30

A defect in Collagen I (the collagen is imperfect!

Our bones will be strong for compression, but weak under torsion.

Question 31

What does collagen normally do for our bones?

Answer 31

Serve as rebar, allowing our bones to be strong under torsion.

Question 32

Treatment for osteogenesis imperfecta

Answer 32

Telescoped rods in the long bones.

Question 33

Cause of rickets

Answer 33

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.

Question 34

What is osteomalacia?

Answer 34

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.

Question 35

Example of a fast-twitch dominant muscle

Answer 35

Latissimus dorsi (can do a few pull-ups, but not a hundred)

Question 36

Example of a slow-twitch dominant muscle

Answer 36

The tongue