Bone Tissue Flashcards

1
Q

6 Functions of the skeletal system

A

support, protect, movement, mineral homeostasis, blood cell production, triglyceride storage

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

7 Parts of a long bone

A

diaphysis, epiphyses, metaphyses, articular cartilage, periosteum, medullary cavity, endosteum

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

Diaphysis

A

long bone shaft

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

Epiphyses

A

proximal and distal ends of the long bone

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

Metaphyses

A

region between the diaphysis and epiphysis; contains an epiphyseal (growth) plate

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

Epiphyseal plate

A

layer of hayline cartilage that allows the diaphysis of the bone to grow in length; becomes epiphyseal line when growth stops

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

Articular cartilage

A

thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms a joint; reduces friction and absorbs shock

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

Periosteum

A

tough connective tissue sheath with blood supply that surrounds bone surface wherever it is not covered by articular cartilage; protects bone, assists in fracture repair, nourishes, attachment point for ligaments and tendons

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

What attaches periosteum to underlying bone?

A

perforating fibers (Sharpey’s fibers)

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

Medullary (marrow) cavity

A

hollow cavity with diaphysis that contains fatty yellow bone marrow and blood vessels in adults

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

Endosteum

A

thin membrane that lines medullary cavity

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

What is the most abundant mineral salt in osseous tissue?

A

calcium phosphate

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

4 Cells in bone tissue

A

osteoprogenitor, osteoblasts, osteocytes, osteoclasts

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

Osteoprogenitor

A

undergo cell division and develop into osteoblasts; found along the inner portion of the periosteum, in the endosteum, and in the canals within bone that contain blood vessels

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

Osteoblasts

A

synthesize and secrete collagen fibers and other compounds to form ECM, initiate calcification; mature into osteocytes

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

What is calcification?

A

as mineral salts are deposited in the framework formed by the collagen fibers of the ECM, they crystallize and the tissue hardens

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

Osteocytes

A

mature bone cells, maintain daily homeostasis (eg. exchange of nutrients and wastes with blood)

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

Osteoclasts

A

releases powerful lysosomal enzymes and acids on the side of the cell that faces the bone surface that digest the protein and mineral components of underlying ECM (bone resorption); help regulate blood calcium levels

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

Compact bone

A

found beneath the periosteum of all bones and makes up the bulk of the diaphysis of long bones, provides protection and support

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

How are osteons arranged in compact bone?

A

aligned in the same direction and are parallel to the length of the diaphysis

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

Concentric lamallae

A

circular plates of mineralized ECM of increasing diameter, surrounding a small network of blood vessels and nerves located in the central canal

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

Lacunae

A

spaces between lamallae that contain osteocytes

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

Canaliculi

A

radiate from lacunae, filled with ECM, contain projections of osteocytes

24
Q

Interstitial lamallae

A

lamallae between neighbouring osteons; also have lacunae with osteocytes and canaliculi

25
Q

Interosteonic (Volkmanns or perforating) canals

A

passages through the periosteoum in compact bone that house blood vessels and nerves

26
Q

Circumferential lamallae

A

arranged around the entire outer and inner circumference of the shaft of a long bone; external and internal circumferential lamallae

27
Q

Perforating (Sharpey’s) fibers

A

connect external circumferentail lamallae to periosteum

28
Q

Spongy bone

A

does not contain osteons, always in the interior of the bone, contain red and yellow bone marrow; consists of lamellae that are arranged in an irregular pattern of thin columns called trabeculae

29
Q

Trabeculae

A

lamallae arranged in irregular pattern of thin columns; consists of concentric lamallae, osteocytes that lie in lacunae, and canaliculi that radiate outward from the lacunae

30
Q

Where is red bone marrow located?

A

hip, ribs, sternum, vertebrae, and the proximal end of humerus and femur

31
Q

Which blood vessel enters through the diaphysis and how does it enter the compact bone?

A

nutrient artery; nutrient foramen

32
Q

What does the nutrient artery do upon entering the medullary cavity and what does it supply?

A

divides into proximal and distal portions that extend as far as the epiphyseal plate; supplies inner part of compact bone tissue and the spongy bone and red bone marrow

33
Q

What blood vessels supply the metaphyses?

A

metaphyseal artery and nutrient artery

34
Q

What blood vessel supplies the epiphyses?

A

epiphyseal artery

35
Q

3 Places that veins are present in the bone

A

(1) nutrient vein with nutrient artery exit through the diaphysis, (2) epiphyseal and metaphyseal veins accompany their arteries and exit through the epiphyses and metaphyses, (3) periosteal veins and exit through same

36
Q

What supplies the periosteum?

A

periosteal arteries; enter through interosteonic (Volkmanns) canals

37
Q

In what situations does ossification occur?

A

(1) embryo (2) infancy to adult (3) remodelling of bone (4) repair of fractures

38
Q

Intramembranous ossification

A

bone forms directly within mesenchyme, which is arranged in sheetlike layers that resemble membranes

39
Q

Endochondrial ossification

A

bone forms within hyaline cartilage that develops from mesenchyme

40
Q

2 Patterns of bone formation in embryo

A

intramembranous and endochondrial

41
Q

Which bones are formed via intramembranous ossification?

A

flat bones of the skull, most facial bones, mandible, medial part of clavicle

42
Q

4 Steps of intramembranous ossification

A

(1) development of ossification center (2) calcification (3) formation of trabeculae (4) development of periosteum

43
Q

Ossification center

A

site where messynchymal cells cluster and differentiate; step in intramembranous ossification

44
Q

6 Steps in endochondrial ossification

A

(1) development of the cartilage model (2) growth of the cartilage model (3) development of the primary ossification center (4) development of the medullary (marrow) cavity (5) development of the secondary ossification center (6) formation of articular cartilage and the epiphyseal plate

45
Q

Zones of cartilage in the epiphyseal plate

A

(1) resting (2) proliferating (3) hypertrophic (4) calcified

46
Q

Growth of long bones in length involves what 2 steps?

A

(1) interstitial growth of cartilage on the epiphyseal side of the epiphyseal plate, and (2) replacement of cartilage on the diaphyseal side of the epiphyseal plate with bone by endochondrial ossification

47
Q

Growth in thickness steps

A

(1) periosteal cells differentiate into osteoblasts which become surrounded by ECM and are then osteocytes. This forms ridges on either side of a periosteal blood vessel; (2) the ridges fuse together to form a tunnel that encloses the blood vessel; (3) ostoblasts in the endosteum deposit bone ECM forming concentric lamallae; (4) osteoblasts continue to form lamallae which further increases the thickness

48
Q

Bone remodelling

A

ongoing replacement of old tissue by new bone tissue

49
Q

Bone resorption

A

removal of minerals and collagen fibers by osteoclasts

50
Q

Bone deposition

A

addition of minerals and collagen fibers to bone by osteoblasts

51
Q

Factors affecting bone growth and remodelling

A

minerals, vitamins, hormones

52
Q

Important hormones for bone growth

A

insulin-like growth factors (IGFs), thyroid hormones, insulin, and sex-hormones

53
Q

What is the most important hormone in regulating calcium levels?

A

parathyroid hormone

54
Q

What does PTH do?

A

increases blood calcium levels by increasing osteoclast activity which increases bone resorption; also acts on kidneys to decrease loss of calcium in urine

55
Q

What is calcitriol?

A

active form of vit D, promotes absorption of calcium from foods which elevates blood calcium levels

56
Q

What does calcitonin do?

A

inhibits osteoclast activity, speeds up bones reuptake of calcium; decreases blood calcium levels