Chapter 6 Flashcards

1
Q

Six main functions of skeletal system

A

Support
Protection
Assistance in movement
Mineral homeostasis (storage/release)
Blood cell production
Tryglyceride storage

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

Explain how bones control mineral homeostasis

A

Bone stores minerals, especially calcium and phosphorus and release on demand into blood

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

What Percentage of body mass is bone? What percentage of calcium is stored in bone

A

18
99

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

Explain blood cell production in bones

A

Red bone marrow produces RBC WBC and platelets: called hemopoises

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

Red bone marrow is made of what? Where is it found

A

Consists of blood cells Adipocytes fibroblasts macrophages in network of reticular fibers

Found in bones of fetus/ some adult (hip,ribs,sternum,vertebrae,skull, ends of humerus/femur)

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

Explain tryglyceride storage in bones

A

Yellow bone marrow consists of mainly adipose cells=potential energy reserve

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

Diaphysis

A

Bone shaft

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

Epiphyses

A

Proximal/distal end

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

Metaphyses

A

Between diaphyses/epiphyses

Contains epiphyseal plate=hyaline cartilage allowing diaphyses to grow

Epiphyseal line: at 14-24 replaces plate with bone

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

Articular cartilage

A

Thin layer hyaline cartilage covering epiphyseal at joint, no perichondrium/BV=limited repair

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

Periosteum/layers

A

Thought connective tissue sheath/blood supply surrounds bone not covered by articular cartilage

Outer fibrous layer: dense irregular connective tissue
Inner osteogenic layer: cells

Protects repairs nourish attachment point (ligaments/tendons)

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

Perforating fibers

A

Thick bundles of collagen attatching periosteum to bone

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

Medullary cavity (marrow cavity)

A

Hollow space in diaphyses containing YBM/BV, minimizes weight of bone

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

Endostuem

A

Thin membrane lines medullary cavity, has bone forming cells/connective tissue

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

Other name for bone

A

Osseous tissue

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

ECM of bone

A

15% water
30% collagen fibers
55% crystallized minerals salts

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

Hydroxyapatite

A

Calcium phosphate and calcium hydroxide

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

Calcification

A

Mineral salts crystallized=tissue hardens
Requires collagen fibers

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

What helps bone hardness/flexibility

A

Crystallized inorganic mineral salts=hardness
Collagen fibers=flexibility

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

Cells in bone tissue

A

Osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts

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

Osteoprogenitor cells

A

Unspecialized bone stem cells become osteoblasts
Found along Inner portion of periosteum, in endosteum, in canal in bone containing BV

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

Osteoblasts

A

Bone building cells, synthesize/secrete collagen fibers, ECM, initiate calcification
When trapped in their secretions (ECM) become osteocytes

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

Osteocytes

A

Mature/main bone cells, maintains bones daily metabolism

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

Osteoclasts

A

Huge cells from fusion of 50 monocytes (WBC)
Ruffled border releases lysosomal enzymes, breakdown ECM=bone resorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Compact bone tissue

A

Few spaces=strongest
Found beneath periosteum of all bones/most diaphyses of long bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Osteons (Haversian) systems

A

Repeating concentric lamellae arranges around osteonic (Haversian/central) canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Concentric lamellae

A

Circular plates of mineralized ECM in increasing diameter (tree rings)

28
Q

Lacunae

A

Spaces between concentric lamellae

29
Q

Canaliculi

A

Radiate from lacunae
Filled with ECM, system of interconnected canals in bone for O2s/nutrients/wastes

30
Q

How are osteons arranged in compact vs spongy

A

Aligned in same direction and are parallel to the length of diaphyses

No osteons

31
Q

Interstitial lamellae

A

Area between neighbouring osteons
Have lacunae with osteocytes/Canaliculi

32
Q

Interosteonic canals

A

BV/nerves form periosteum penetrate the compact bone thought these these transversely
Connect with medullary cavity periosteum central canals

33
Q

Circumferential lamellae

A

Around entire outer/inner circumference of shaft of long bone

External:under periosteum connected by perforating fibers
Internal: lines medullary cavity

34
Q

Spongy bone tissue

A

Always interior covered by compact bone for protection
Spongy=light=easier to move

35
Q

Trabeculae

A

Spongy
Irregularly patterned lamellae
Consists of concentric lanellae, osteocytes that lie in lacunae, Canaliculi radiate outward from lacunae
Support RBM and protect

36
Q

Periosteal arteries

A

Small arteries with nerves enter diaphysis through interosteonic canal to supply periosteum/outer compact bone

37
Q

Nutrient artery

A

Passed through a hole in the compact bone called nutrient foramen
Supplies inner compact bone/spongy bone/RBM as far as epiphyseal plates/lines

38
Q

Nutrient veins

A

One of two a company nutrient artery, exit through diaphyses

39
Q

Epiphyseal veins/metaphyseal veins

A

Numerous acoompany respective arteries/exit areas

40
Q

Periosteal veins

A

Many accompany respective arteries be exit periosteum

41
Q

Nerves into bone

A

Accompany BV that supplies bones periosteum is rich with nerves

42
Q

Ossification

A

Process by which a bone forms

43
Q

Initial bone formation in an embryo/fetus (don’t think this is right but two kinds)

A

Intramembraneous ossification: forms within Mesenchyme, simpler

Endochondral ossification: replacement of cartilage by bone

44
Q

Intramembraneous ossification steps

A

1) Development of ossification center:
Chemical message cause Mesenchyme to cluster(center) and differentiate into Osteoprogenitor cells then osteoblasts

2) calcification: secretion of ECM stops, osteocytes lie in lacunae extend cytoplasmic processes into Canaliculi
Calcium/mineral salts deposit into ECM=hardens/calcified

3) formation of trabeculae: ECM develops into trabeculae=forms spongy around BV
Connective tissue in trabeculae differentiates into RBM

4) development of the periosteum: Mesenchyme condenses=periosteum
Thin layer replaced surface layers of spongy bone

45
Q

Endochondral ossification steps simple

A

Development of cartilage model
Growth of cartilage model
Development of the primary ossification center
Development of the medullary (marrow) cavity
Development of secondary ossification center
Formation of articular cartilage and the epiphyseal (growth) plate

46
Q

Development of cartilage model

A

Mesenchyme crowds into shape of bone, develop into chondoblasts, perichondrium develops

47
Q

Growth of cartilage model

A

division of chondrocytes=growth

Interstitial/endogenous growth: length chondrocytes dividing/secretion ECM

Appositional/exogenous growth: thickness, deposition of ECM on surface form perichondrium

48
Q

Development of primary ossification center

A

Nutrient artery penetrates, perichondrium forms bone=perisoteum, capillaries induce growth of primary ossification center (bone tissue replaces cartilage)

49
Q

Development of medullary canal

A

Bone breakdown by osteoclasts =canal

50
Q

Development of secondary ossification center

A

Secondary ossification centres In epiphyses

51
Q

Formation of articular cartilage formation

A

Consist of hyaline cartilage

52
Q

Growth in length

A

Interstitial forth of cartilage on epiphyseal side of epiphyseal plate

Replacement of cartilage with bone by Endochondral ossification of diaphysial side

53
Q

Four zones of epiphyseal plate/growth in length

A

1) zone of resting cartilage: consist of small scattered chondrocytes, anchor epiphyseal plate to epiphyses

2) zone of proliferation cartilage: larger chondrocytes arranged like coins, interstitial growth/secrete ECM replace diaphyses side

3) zone of hypertonic cartilage: even larger chondrocytes arranged in columns

4) since of calcified cartilage, few chondrocytes dead as ECM calcified, osteoclasts/osteoblasts use Endochondral ossification=new diaphyses

54
Q

Growth in thickness

A

1) periosteal cells differentiate into osteoblasts, surrounded by ECM=osteocytes, forms bone ridges

2) ridges fold/fuse, groove becomes tunnel that encloses BV, periosteum=endosteum

3)osteoblast in endosteum deposit bone ECM=forming new concentric lamellae

4) osteoblasts under periosteum deposit circumferential lamellae=thicnkess

55
Q

Bone remodelling

A

Bone reposition: removal of mineral/collagen fibers by osteoclasts (destroy ECM)

Bone deposition: addition of mineral/collagen fibers by osteoblast (add ECM)

56
Q

Factors affecting bone growth/remodelling

A

1) minerals: large # Ca/P, small Mg/Fl/Mn
2) vitamins: a,c,d,b12
3) hormones: insulin like growth factors(IGFs), thyroid hormones, insulin, sex hormones
4) exercise
5) aging: Less sex hormone

57
Q

How does vitamin A affect bone growth

A

Stimulates osteoblast

58
Q

How does vitamin C affect bone growth

A

Synthesis of collagen

59
Q

How does vitamin D affect bone growth

A

Increase absorption of Ca=bone growth

60
Q

How does vitamin K/B12 affect bone growth

A

Synthesis of bone proteins

61
Q

How does insulin like growth hormones affect bone growth

A

Produced by liver/bone tissue, stimulate osteoblasts, promote cell division at epiphyseal plate/periosteum, enhance syntheses of protein

62
Q

How does thyroid hormones affect bone growth

A

T3/t4 stimulate osteoblasts

63
Q

How does insulin affect bone growth

A

Increase synthesis of bone proteins

64
Q

How do sex hormones affect bone growth

A

Increase osteoblasts activity, synthesis of bone ECM, growth spurt, shut down growth at epiphyseal plate slow resorption

65
Q

Parathyroid hormone

A

PTH
Increases blood ca2+ level, decrease loss in urine, stimulates formation of calcitriol

66
Q

Calcitonin

A

CT
Inhibits acidic of osteoclasts, speeds blood Ca2+ uptake by bone/accelerates deposition
(Promotes bone formation/lowers blood Ca2+)