Brainscape's Knowledge GenomeTM

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


See full index

Musculoskeletal > Congenital And Acquired Bone Diseases > Flashcards

Congenital And Acquired Bone Diseases Flashcards

0
Q

Make up of the bones?

A

65% inorganic : calcium hydroxyapatite

35% organic: collagen

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

How many bones in the body?

A

206

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

What is osteoid?

A

Bone that isn’t mineralized

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

How long does it take to mineralized bone?

A

12-15 days

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

What are the types of bone cells?

A

Osteoprogenitor cells, osteoblasts, osteoclasts, osteocytes

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

What do osteoblasts do?

A

Synthesize osteoid (type I collagen, 90% of organic part)
Initiate mineralization
Mediate osteoclast activity (have PTH receptors)

These eventually surrounded by matrix

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

Explain osteocytes

A

They are encased in bone, and communicate through canaliculi with osteocytic cell processes.

They have stress and hormone receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do osteoclasts do?

A

Responsible for resorption and remodeling.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What cytokines do osteoclasts need to differentiate?

A

IL-1, IL-3, IL-6, IL-11, GM-CSF, and M-CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

So describe how osteoclasts become osteoclasts

A

They’re derived from from stem cells that produce macrophages. RANK ligand binds it’s receptor RANK on cell surface of osteoclast precursors. If this occurs in the background of M-CSF the precursor cells produce functional osteoclasts. Osteoprotegerin is a decoy for RANKL and prevents binding, thus preventing bone resorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Endochondral bone formation… What happens basically?

A

Mesenchyme –> cartilage anlage (model for future bone)–> cartilage becomes bone

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

What’s a growth plate?

A

Cartilage between ossification centers, in the epiphysis. In growing bones blood is supplied to growth plate, but growth plate is sealed in adults.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What’s a consequence of children’s bones having richer blood supply?

A

They grow, duh. But they are more prone to osteomyelitis.

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

What is osteogenesis imperfecta?

A

A family of diseases with mutations in type I collagen genes. There are several subtypes. Most are autosomal dominant. In most cases teeth are also deformed

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

Type I OI?

A

Make too little pro-a1(1)

So normal stature, lax joints, hard of hearing

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

Type II OI?

A

Pro-a1(1) is too short. Collagen is made but degrad intracellularly. Bones break in utero or in birth and baby dies.

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

Type III OI?

A

Triple helix doesn’t form well.

So get short kid with many fractures, progressive kyphosis, hard of hearing
Bad cases are lethal in childhood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Type IV OI?

A

Pro-a2(1) is too short

So short kid with somewhat fragile bones

18
Q

Four major clinical criteria for OI?

A

Osteoporosis, blue sclerae, dentingenesis imperfecta, premature otosclerosis

Need 2 of 4 criteria to diagnose OI

19
Q

Why does blue sclerae happen and what diseases might you see it in?

A

From thinning of then sclera so underlying choroid is visible

Seen in OI (duh), pseudoxanthoma elasticum, Ehlers-Danlos syndrome, and Marfan disease

Very rarely in iron deficiency, RA, or myasthenia gravis

20
Q

Achondroplasia - what is it?

A

Most common cause of inherited dwarfism

From a reduction in Chondrocytes at growth plate

21
Q

What does a patient with achondroplasia look like?

A

Short extremities, normal trunk, large head, normal sexuality and intelligence

22
Q

What are the genetic risks of achondroplasia?

A

Locus is the receptor for fibroblast growth factor 3 on chromosome 4p

Risk factor is advanced paternal age

23
Q

On little people big world the Roloffs are two dwarfs and they have four kids. Only one is a dwarf. Why do you think that’s weird?

A

It’s an autosomal dominant disease. I think it’s strange they only had one of 4 dwarf kid

24
Q

Explain osteopetrosis real quick

A

Failure of osteoclasts to resorb tissue. Bone just keeps building up. Bone marrow is occluded by weak bone. Bone is brittle.

25
Q

What’s the most severe type of human osteopetrosis?

A

The malignant, infantile, autosomal recessive variant (ARO) from specific genes responsible for osteoclast function.

26
Q

Are there more or less osteoclasts in osteopetrosis?

A

Usually normal. Can be increased slightly.

27
Q

What does a X-ray in osteopetrosis look like?

A

Bones are diffusely sclerotic. Bulbous ends.

28
Q

What is the role of RANKL in osteopetrosis?

A

Loss of function mutations of RANK ligand lead to recruitment and activation of osteoclasts that doesn’t occur properly.

29
Q

What is osteoporosis?

A

A disease of the skeletal system characterized by low bone mass and deterioration of bone tissue. Leads to increased risk of bone fractures typically in wrist, hip, and spine.

30
Q

What are some factors leading to pathogenesis of osteoporosis?

A

Menopause: decreased serum estrogen, increased IL-1, IL-6, and TNF, increased RANK & RANKL, and increased osteoclast activity

Aging: decreased replicative activity of osteoprogenitor cells, decreased synthetic activity of osteoblasts, decreased biologic activity of matrix-bound growth factors, and reduced physical activity.

31
Q

What is a difference I might see in an electron micrograph of osteoporotic bone?

A

Thin trabeculae with microfractures

32
Q

Tell me about Paget disease of bone.

A

Unbalanced and excessive osteoclast and osteoblast function leading to increased bone turnover.
May be osteolytic, osteoblastic, or mixed.

33
Q

Pattern of bone in Paget’s

A

Mosaic pattern of lamellar bone, skull and long bones

34
Q

Patients with paget’s are predisposed to what diseases?

A

Osteopenia sarcoma, chondrosarcoma, and malignant fibrous histiocytoma

35
Q

Key clinical points when thinking of Paget’s

A

Thick skull, deafness, kyphosis, pain, and bowed legs

36
Q

What is osteomalacia?

A

Failure of bone to mineralized in an adult

37
Q

What am I going to think of if a person has osteomalacia?

A

Inadequate intake of Vitamin D and/or Calcium. Can lead to bone pain and fracture

38
Q

What results from vitamin d deficiency in kids?

A

Rickets

39
Q

What stain is used for osteomalacia?

A

Von Kossa stain

40
Q

What are some causes of hyperparathyroidism?

A

Primary- adenoma

Secondary- prolonged hypocalcemia with compensatory hypersecretion

41
Q

What happens if you have unabated PTH secretion?

A

It’s detected by osteoblasts and results in release of mediators that stimulate osteoclasts and bone resorption

42
Q

Some results of hyperparathyroidism?

A

Dissecting osteitis, brown tumors, osteitis fibrosa cystica

43
Q

What’s a brown tumor?

A

NOT a neoplasm, it’s a focus of increased osteoclast activity

Musculoskeletal (3 decks)

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