Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology 2 Block 2 > Metabolic diseases of bone > Flashcards

Metabolic diseases of bone Flashcards

1
Q

what is osteoporosis?

A

Refers to increased porosity of skeleton due to loss of organic bone matrix and minerals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the effects of osteoporosis?

osteoporosis results in what?

A
  • decreased bone mass and density.
  • decreased thickness of cortical and trabecular** bone.

fractures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

the risk of osteoporosis is based on what?

A

Risk of OP is based on peak bone mass (30 years, based on genetics, diet, exercise) and the rate of bone loss that follows thereafter.

  • after 30 you lose 1% bone mass each year
    • lost faster if there is no exercise with weights, poor diet or less estrogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the most common forms of osteoporosis?

A

senile

postmenopausal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is Postmenopausal osteoporosis?

A

it occurs secondary to estrogen deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the normal effects of estrogen on bone?

A
  • Stimulates OPG production
  • Decreases production of M-CSF
  • Decreases response of osteoclasts to RANK ligand.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the normal net result of estrogen on bone?

A
  • Decreased formation of osteoclasts
  • Decreased bone resorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

if there is estrogen deficiency there will be what?

A
  • ↑production of IL-1 and TNF by monocytes causing
    • Increased activity of RANK ligand and M-CSF
      • increase osteoclast activity = bone loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the clinical findings of osteoporosis?

A
  • Bone pain
  • Weight bearing bones predisposed to #
    • Compression fractures of vertebral bodies (most common)
    • Colles’ fracture of distal radius.
    • fracture of femoral neck.
  • Loss of height and kyphosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what test can you use to diagnose osteoporosis?

A

Dual energy X ray absorptiometry (DEXA) - to evaluate bone density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what measures can be taken to prevent postmenopausal osteoporosis?

A
  • weight bearing exercises: walking, not swimming
  • calcium, vitamin D supplements
  • estrogen replacement therapy (currently not recommended)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the treatment for osteoporosis?

A

Bisphosphonates: induce apoptosis of osteoclasts.

Calcitonin: inhibits osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how do you differentiate between osteomalacia and osteoporosis?

A

in osteoporosis, these are normal: Serum calcium, phosphate, PTH and alkaline phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Osteitis Fibrosa Cystica?

what is another name for this?

A

The cause is increased PTH

primary hyperparathyroidism:

  • Parathyroid adenoma  ↑ PTH
  • Parathyroid hyperplasia  ↑ PTH

secondary hyperparathyroidism:

  • prolonged hypocalcemia (renal failure) increased PTH

von Recklinghausen disease of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what characterizes Osteitis Fibrosa Cystica?

A

Wide spread osteolytic lesions.

Deformity , microfractures

Secondary hemorrhages with formation of cysts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

in Osteitis Fibrosa Cystica, what do you look for?

A

“Brown tumor” of bone characterized by: Cystic spaces lined by multinucleated osteoclasts, filled with fibrous tissue, and with brown discoloration resulting from hemorrhage.

17
Q

what is rickets?

A

Cause is vitamin D deficiency in children

18
Q

what is osteomalacia?

A

Cause is vitamin D deficiency in adults

19
Q

Rickets and osteomalacia have what findings in common?

A
  • Decreased mineralization of newly formed bone.
  • Usually caused by deficiency or abnormal metabolism of vitamin D.
20
Q

what is Renal osteodystrophy?

how does it happen?

A

Osteomalacia secondary to chronic renal disease.

Chronic renal failure causes: Hypocalcemia

  • Due to lack of conversion of inactive vitamin D into active vit.D
  • Hypocalcemia results in secondary hyperparathyroidism
  • PTH secretion stimulates osteoclast activity
21
Q

what is Osteomyelitis?

what is the most common cause?

A

Refers to inflammation of bone and bone marrow.

due to infections by: Pyogenic (pus forming) bacteria

(Pyogenic Osteomyelitis)

22
Q

Pyogenic Osteomyelitis usually occurs in who?

what bacteria can cause osteomyelitis?

A

children and young adults

  1. Staphylococcus aureus* (most common cause 90%)
  2. N gonorrhoeae: sexually active young adults
  3. Salmonella: sickle cell disease
  4. Pseudomonas : IV drug abusers, diabetics and puncture of foot through rubber footwear.
  5. Pasturella multocida: cat or dog bite
  6. Mycobacterium tuberculosis : involves spine ( Pott’s disease)
23
Q

what is this?

A

osteomyelitis

24
Q

what are the 3 routes these organisms use to reach the bone in osteomyelitis?

A
  1. Hematogenous spread (most common) (Seeding of bone after bacteremia)
  2. Direct inoculation
  3. Spread from an adjacent site of infection
25
Q

in osteomyelitis, what are the bones affected in Infant and children?

A

tibia, femur, humerus (long bones)

26
Q

in osteomyelitis, what are the bones affected in Infant and adults?

A

(small bones) - vertebrae, pelvic bones

27
Q

What region of the bone affected in adult osteomyelitis?

A

epiphysis

28
Q

what are the 2 morphologies of osteomyelitis?

A
  1. acute osteomyelitis:
    • look for cell death and pus formation.
    • Pus may reach the Periosteum forming a subperiosteal abscess.
      • ​if abscess ruptures = fluid drained into sinus tract
      • ​​neutrophils kill bone cells
  2. Chronic osteomyelitis:
    * characterized by replacement of acute inflammatory cells
    * A sleeve of new bone formation may surround the infected necrotic area = involucrum
29
Q

what are the clinical findings of osteomyelitis?

A
  • Fever and severe pain over the affected area.
  • reluctance to use affected extremities.
  • Localized area of tenderness
  • Erythema
  • Swelling
30
Q

investigations will reveal in osteomyelitis these findings?

A
  • Leukocytosis
  • Raised ESR
31
Q

what investigations can you order for osteomyelitis?

A
  • X ray:
    • Early stage (10 days) - may be normal
    • Slow periosteal elevation
    • Lytic focus of bone destruction with surrounding sclerosis.
  • Radionuclide bone scan:
  • Blood cultures : usually positve
  • Bone biopsy
32
Q

what is a complication of osteomyelitis?

A
  • Draining Sinus tract to the skin surface
    • Danger of Squamous cell carcinoma developing at orifice of sinus tract.
  • Extension of infection to adjacent joint
    • leads to pyogenic arthritis.
  • septicemia and infective endocarditis
33
Q

what is Tuberculous Osteomyelitis?

A

Occurs secondary to tuberculous infection located elsewhere.

  • Active tuberculosis of lung.
  • TB of GIT and lymphnodes
  • Characteristically occurs in:

Vertebrae (Pott’s spine or disease)

34
Q

what are the clinical findings in Tuberculous Osteomyelitis?

A
  • Back pain
  • Stiffness,
  • Deformity (kyphosis) ,
  • Neurological abnormalities (Pott’s paraplegia)
  • Fever, night sweats and weight loss.
35
Q

what will you find in histology in tuberculous osteomyelitis?

A

Granulomas with caseous necrosis on histology.

36
Q
  1. what is the most common organism causing osteomyelitis?
  2. what is the most common organism causing osteomyelitis in patients with sickle cell?
  3. what is the most common organism causing osteomyelitis in patients with IV drug abusers?
  4. what is the most common organism causing osteomyelitis in patients with dog and cat bites?
  5. what is the most common organism causing osteomyelitis in patients with nail puncture through rubber footwear?
A
  1. Staphylococcus aureus
  2. Salmonella paratyphi*
  3. pseudomonas.
  4. Pasteurella multocida (a gram negative rod)
  5. pseudomonas*

Pathology 2 Block 2 (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions