Bone Development Flashcards

1
Q

What type of ossification directly develops from mesenchyme?

A

Intramembranous ossification (never has a cartilage stage)

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

What type of ossification has a cartilage precursor?

A

Endochondral ossification

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

What is the process depicted in the image?

A

Intramembranous ossification

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

What protein begins ossification?

A

BMP

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

Locations of intramembranous ossification

A

Flat bones of skull and face and the scapula

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

Locations of endochondral ossification

A

Arms and legs, vertebral column, base of skull (skull is a composite of both types)

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

How many ossification centers do long bones have?

A

2: primary (forms in the center of the bone) and secondary (forms in the epiphysis)

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

How many ossification centers do short bones have?

A

1: primary

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

Endochondral Ossification Steps

A
  • fetal hyaline cartilage develops
  • cartilage calcifies and periosteal bone collar forms around diaphysis
  • primary ossification center forms in diaphysis
  • secondary ossification center forms in epiphysis
  • bone replaces cartilage (except articular and epiphyseal plates)
  • epiphyseal plates ossify and form epiphyseal lines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 6 long bones?

A
  • femur
  • tibia
  • fibula
  • humerus
  • radius
  • ulna
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Endochondral bone growth: lengthening

A

Interstitial growth in the epiphyseal plate

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

Endochondral bone growth: thickening

A

Appositional a little growth under the periosteum

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

What is a mixed spicule?

A

A transition area that possesses both cartilage and bone

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

Mixed spicule labeled components

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

ID

A

Mixed spicule

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

ID

A

short bone (phalanges)

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

ID

A

long bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is the epiphyseal/growth plate located?

A

Between the primary and secondary ossification centers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

ID

A

Growth plate

20
Q

Growth plate labeled zones and functions

A
21
Q

What zone are mixed spicules located?

A

Ossification zone

22
Q

Epiphyseal plate vs epiphyseal line

A

Children have a plate and adults have a line

23
Q

Why is the jaw an exception to intramembranous ossification?

A

Because it develops secondary cartilage for the condyle
*It is considered intramembranous, but with a growth plate

24
Q

If cartilage is eroded in a joint, can it be replaced?

A

No

25
Q

Since there is no periosteum in joints, where do they receive their nutrients?

A

Synovial fluid

26
Q

How long does it take to remodel bones?

A

3-7 years

27
Q

How long does bone resorption take?

A

2-3 weeks

28
Q

How long does bone deposition take?

A

2 months

29
Q

What produces RANKL in bone?

A

PTH produces RANKL

30
Q

In bone remodeling, what are the two cones?

A

-Cutting cone, area of remodeling bone (osteoclasts)
-Closing cone, area of depositing bone (osteoblasts)

31
Q

What is a moderate loss of bone density referred to?

A

Osteopenia

32
Q

What is a severe loss of bone density referred to?

A

Osteoporosis

33
Q

What causes osteoporosis?

A

An imbalance between osteoblasts and osteoclasts

34
Q

T1 Osteoporosis

A
  • post‐menopausal women due to decreased estrogen
35
Q

T2 Osteoporosis

A
  • elderly individuals usually 70+ and older (affects everyone)
36
Q

T3 Osteoporosis

A
  • secondary to drug therapy (corticosteriod) or diseases
37
Q

Normal bone vs osteoporosis

A
38
Q

Peak bone density age (men and woman)

A

20s-40s

39
Q

Are osteoids mineralized?

A

NO

40
Q

What secretes matrix vesicles

A

Osteoblasts

41
Q

What is rickets and what causes it

A
  • Defective mineralization of developing bones in kids
  • Vitamin D or calcium deficiencies
42
Q

What is osteomalasia and what causes it

A
  • Defective mineralization of developing bones in adults
  • Makes bones soft
43
Q

How many steps in fracture repair?

A

4

44
Q

What are the steps to fracture repair

A
  • Hematoma formation: mass of clotted blood
  • Callus formation: soft callus (cartilaginous) splint
  • Bony callus formation: hard callus (spongy/bony) splint
  • Bone remodeling: replace spongy bone with compact bone
45
Q

What is the mediator between osteoblast and osteoclast?

A

RANKL