Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Histology > Bone And Ossification > Flashcards

Bone And Ossification Flashcards

(82 cards)

Start Studying
1
Q

2 ways in which bone is formed

A

Endochondral ossification
Intramembranous ossificatiom

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

Endochondral ossification

A

Transformation of a pre-existing cartilaginous model or proformer

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

Intramembranous ossification

A

Direct ossification of a primitive mesenchymal connective tissue

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

What is the first stage of long bone formation

A

Creation of cartilaginous models or proformers
Subsequently converted to bone

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

What are proformers made of

A

Hyaline cartilage

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

Hyaline cartilage of proformers synthesis

A

By chondroblasts
Produce a glassy amorphous looking matrix within which the cells become trapped causing them to transform into less synthetically active chondrocytes

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

Formation of chondroblasts

A

Differentiate from progenitor cells within embryonic connective tissue (mesenchyme)

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

What encapsulates hyaline cartilage

A

Fibrous perichondrium that contains both progenitor cells and differentiated chondroblasts

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

Major component of osteoid

A

Type 1 collagen

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

Primary bone

A

First type of bone to be produced in a developing bone

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

Structure of primary bone

A

Randomly woven collagen
Calcium is amorphous not crystalline

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

What type of bone is present at birth

A

Primary bone

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

Structure of secondary bone

A

Collagen organised into regularly arranged laminae
Calcium deposited as hydroxyapatite with the long axes of the crystals parallel to the collagen fibres

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

Characteristics of secondary bone

A

Light
Strong

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

How can secondary bone occur

A

Woven bone (open framework)
Compact lamellae
Osteons

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

Osteoclasts

A

Occur frequently in developing bone
Multinucleated cells
Digest bone and play a part in remodelling

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

Original of osteoblasts

A

Differentiate from precursor cells contained within capsule of the proformer or that arrive in the cavity of developing bone via the blood stream

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

Which cells produce bone

A

Osteoblasts

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

Osteocytes

A

When the osteoid is ossified osteoblasts become trapped within the matrix where they regress into a less active form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is contact between osteocytes maintained

A

By minute canaliculi within the bone through which spidery processes from the osteocytes make contact with each ither

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When are long bones first created

A

2nd trimester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do long bones start in utero

A

Hyaline cartilage proformers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which type of cartilage is particularly responsive to growth and sex hormones

A

Epiphyseal cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Growth plates

A

Continue to exist beyond puberty and are largely responsible for the lengthening of bones during childhood and adolescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
1st stage of endochondral ossification
Formation of hyaline cartilage proformers
26
2nd stage of endochondral ossification
The shaft (diaphysis) of the proformer becomes calcified and a bony collar is established around it
27
3rd stage of endochondral ossification
The bony collar is penetrated by blood vessels that bring in more osteoprogenitor cells that differentiate into osteoblasts and lay down bone
28
4th stage of endochondral ossification
A primary centre of ossification is established- involves the erosion of the proformer cartilage and formation of primary bone
29
6th stage of endochondral ossification
Later secondary centres of ossification of formed in the heads (epiphyses) of the bones
30
7th stage of endochondral ossification
As the primary and secondary centres expand the amount of cartilage is reduced so that it becomes restructure to the epiphyseal growth plates that separate the diaphysis from the epiphyses and to the articular surfaces of the bones
31
Epiphyses
Heads of the bines
32
Diaphysis
Shaft of the proformer
33
Where is a primary centre of ossification established
Bony collar around diaphyssi
34
Where is secondary centre of ossification established
Epiphyses
35
Zone of hyperplasia
Chondrocytes of resting cartilage first divide creating columns of progeny
36
Zone of hypertrophy
Newly formed cells grow, eroding the cartilage matrix as they enlarge
37
What remains after zone of hypertrophy
Thin spicules of cartilage The chondrocytes themselves having been released from the matrix and resorbed
38
Zone of ossification
Remnant strands of cartilage become calcified and serve as a substrate to which osteoblasts become attached Osteoblasts then lay down primary bone
39
Appositional growth
Bone is eroded and re-deposited in the outside of the shaft of the bone
40
How does the length of a long bone grow
At a epiphyseal growth plate Zone of hyperplasia Zone of hypertrophy Zone of ossification
41
How does the girth of a long bone increase
Appositional growth
42
Where does intramembranous ossification occur
Flat bones of the skull
43
When does intramembranous ossification start
Second trimester
44
Which type of bone formation requires a proformer
Endochondral ossification
45
1st stage of intramembranous ossification
Small clusters of progenitor cells within a primitive mesenchyme transform into osteoblasts and start to deposit isolated islands of bone
46
2nd stage of intramembranous ossification
As the islands enlarge they coalesce to create an open network of bone
47
3rd stage of intramembranous ossification
Osteoblasts continue to deposit bone on the mesh work until the holes become filled in thereby creating a plate of primary bone
48
4th stage of intramembranous ossification
Primary bone is eroded and replaced with denser more organised lamellar secondary bone
49
What is the end product of osteogenesis
Mature secondary bone
50
Composition of mature bone
5% hydroxyapatite
51
How is bone examined
Native bone is ground into thin slithers with grinding paste
52
Why is the bone specimen not stained
Contrast is created by refraction caused by the crystalline nature of the tissue
53
How is bone treated for examination
Treated with acid and/or chelating agents -procedure removes most of the calcium but organic components are retained
54
What colour does compact lamellar secondary bone stain
Purple/pink
55
What part of the compact lamellar bone stains strongly
The collagen matric
56
What surrounds bone
Periosteum
57
Periosteum
Outer fibrous layer Inner cellular layer - paler staining Site of osteoprogenitor cells
58
Inner cellular layer of periosteum
Contains rows of dark blue staining osteoblasts
59
How does hyaline cartilage normally obtain its oxygen and nutrients
Small pieces of cartilage do not have a direct blood supply, the oxygen and nutrients diffuse through the matrix from the blood vessels in the perichondrium Large masses of cartilage have a conventional blood supply via a capillary bed- during osteogenesis the diaphysis and epiphyses of bone proformers are invaded by blood vessels
60
In which part of a long bone does ossification first occur
Diaphysis
61
Approximately what proportion of primary centres of ossification have formed by the time of birth
Almost all have started to ossify and some are well advanced by this time Carpal and tarsal bones have not begun to ossify
62
Which long bones only have a single epiphyseal growth plate
Distal phalanges of fingers and toes
63
Which are the last sets of bones to begin the process of ossification
Carpal and tarsal bone - begin at age 7/8
64
Why does the cytoplasm of osteoblasts stain purple blue
Cells synthesise large quantities of osteoid Contain a profuse endoplasmic reticulum with large numbers of ribosomes attached to it Ribosomes and DNA stain dark blue
65
What are Volkmann’s canals
Cross connections between the Haversian canals of adjacent osteons
66
Where on a long bone does cartilage persist even after the closure of the growth plate
At the ends as articular cartilage
67
Which hormone promotes the breakdown of bone
Parathormone
68
Howship’s lacunae
Depressions in the surface of bone formed by osteoclasts
69
How to describe bone by origin
Primary (woven) Secondary (lamellar)
70
How to describe bone by mode of formation
Membranous Endochondrial
71
How to describe bone by gross appearance
Spongy/cancellous Compact
72
How to describe bone by formed
Osteons Appositinal
73
Osteoid
Extracellular matrix rich in type 1 collagen, glycosaminoglycans and proteoglycans
74
Osteons
Central Haversian canal containing blood vessel Surrounded by concentric rings of lamellar bone with osteocytes Secondary bine
75
Synovium
Lines the inside of joint capsule 1-4 layers of synovial cells Type A - phagocytes Type B - rich in rER Variable shapes- squamous to cuboidal Richly vascular Highly innervated
76
Type A synovial cells
Phagocytes
77
Type B synovial cells
Secrete synovial fluid Rich in rER
78
Osteoclasts: Are derived from megakaryocytes Are multinucleated Differentiate into osteoprogenitor cells Lie in Haversian canals Synthesise osteoid
Multinucleated
79
Osteocytes: Are dead cells Do not communicate with each other Have more endoplasmic reticulum than osteoblasts Lie on the surface of bones May resorb formed bone matrix
May resorb formed bone matrix
80
Which of these bones is formed by intramembranous ossification? Clavicle Femur Humerus Ischium Scaphoid
Clavicle
81
Why bones are formed by intermembranous ossification
Flat bones of skull Clavicle Mandible
82
Which of the following can be found in Haversian canals? Blood vessels Haematopoietic marrow Osteoclasts Osteocytes Sharpey’s fibres
Blood vessels

Histology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions