Chapter 5 - The Skeletal System Flashcards Preview

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Flashcards in Chapter 5 - The Skeletal System Deck (106)
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0
Q

Two divisions of the skeleton and their meanings

A
  1. Axial - head and center of body (skull, ribs, vertebral column)
  2. Appendicular - movement (limbs, pelvis)
1
Q

How many bones are in the body?

A

206

2
Q

Two types of bone tissue and their meanings

A
  1. Compact bone - dense smooth bone

2. Spongy bone - bone with open spaces within

3
Q

The skeletal system makes up how much of the body?

A

20% of total body mass

4
Q

Four components to the skeletal system

A
  1. Cartilage
  2. Bone
  3. Tendons
  4. Ligaments
5
Q

Functions of the skeletal system along with their specific meanings

A
  1. Protection
  2. Support - rigid structure
  3. Movement - bones act as levers
  4. Storage - Ca, P, and fat
  5. Blood cell production
6
Q

What does cartilage consist of?

A
  1. Cells

2. Extracellular matrix

7
Q

Cartilage cells

A

Chondrocytes

8
Q

Where are the chondrocytes found in cartilage?

A

Lacunae

9
Q

Two components to the extracellular matrix in cartilage

A
  1. Collagen and Elastic fibers

2. Ground substance of chondrotin sulfates

10
Q

What does cartilage lack and what is the cause of lacking this?

A
  • Lacks arteries, veins, and lymphocytes

- It heals very slowly

11
Q

Types of cartilage

A
  1. Hyaline
  2. Elastic
  3. Fibrocartilage
12
Q

What is the most common but weakest cartilage?

A

Hyaline cartilage

13
Q

Structure and location of hyaline cartilage

A

Structure: Chondrocytes, chondroitin sulfate, some collagen
Location: Embryonic skeleton, Articular surfaces, respiratory passages, nasal septum, between ribs and sternum

14
Q

Structure and location of Elastic Cartilage

A

Structure: Chondrocytes, chondrotin sulfate, densely packed elastic fibers
Locations: auricle, tip and lateral walls of nose, epiglottis

15
Q

Most flexible type of cartilage

A

Elastic cartilage

16
Q

The strongest type of cartilage

A

Fibrocartilage

17
Q

Structure and location of fibrocartilage?

A

Structure: Chondrocytes, chondrotin sulfate, densely packed collagen fibers
Location: Intervertebral disc, pubic symphysis, articular cartilage in kneww

18
Q

Surrounds the cartilage

A

Perichondrium

19
Q

What is the perichondrium made out of?

A

Fibrous connective tissue

20
Q

What does the perichondrium provide?

A
  • Support and protection

- New chondrocytes

21
Q

Where is the perichondrium located?

A
  • Hyaline cartilage

- Elastic cartilage

22
Q

Where is the perichondrium absent?

A
  • Articular surfaces

- Fibrocartilage

23
Q

The layers and the functions of the layers for the Perichondrium

A
  1. Outer: binds cartilage to adjacent tissues; provides support and protection
  2. Inner: For growth and maintenance
24
Q

Six steps to appositional growth in cartilage

A
  1. Starts in perichondrium
  2. Mesenchymal cells form inner layer of perichondrium
  3. Mesenchyme move toward matrix to become chondrogenic cells
  4. Chondrogenic cells aggregate and become chondroblasts
  5. Chondroblasts secrete matrix which forces cells apart
  6. Chondroblasts become enclosed in matrix and become chondrocytes
25
Q

Three steps to Interstitial growth

A
  1. Chondrocytes are enclosed in matrix and divide
  2. As they move apart, matrix forms in between them
  3. Growth of cartilage from within
26
Q

Three characteristics of Osseous tissue

A
  1. Made of supportive CT
  2. Contains specialized cells
  3. Solid extracellular matrix
27
Q

What is the solid extracellular matrix in osseous tissue composed of?

A
  1. Osteoid - organic portion, protein fibers
  2. Ground substance - Ca salts
  3. Water
28
Q

Order of the creation of bone cells

A
  1. Osteoprogenitor
  2. Osteoblasts
  3. Osteocytes
29
Q

What do osteoprogenitor cells do?

A
  1. Mesenchymal cells
  2. Predecessor to osteoblasts
  3. Play role in initial bone growth and fracture repair
30
Q

Increased osteoblast activity equates to what?

A

Stronger bone

31
Q

Characteristics and derivations of osteoblasts?

A
  • Derived from osteogenic cells and predecessor to osteocytes
  • Secrete osteoid
  • Common in growing bone
32
Q

Characteristics of osteocytes

A
  1. Mature cells
  2. Exist within matrix
  3. Maintain Ca and PO4 homeostasis
  4. Found in spaces called lacunae
33
Q

Break down of bone

A

Osteolysis

34
Q

Cells involved in osteolysis

A

Osteoclasts

35
Q

Increase in osteoclast activity equate to what?

A

Weaker bone

36
Q

How do osteoclasts form?

A

They form from the fusion of many white blood stem cells

37
Q

Two components that make up the bone matrix

A
  1. Inorganic materials

2. Osteoid

38
Q

What composes the inorganic materials in the bone matrix?

A
  1. Brittle salts - Hydroxyapatite, calcium carbonate, ions
39
Q

How much of the bone matrix is composed of inorganic materials?

A

65%

40
Q

What are the things that up the osteoid in the bone matrix?

A
  1. Organic

2. Collagen, glycoproteins, and proteoglycans

41
Q

What percentage of the cell matrix in bone is composed of osteoid?

A

35%

42
Q

What are the two prominent qualities to the bone matrix?

A

Flexible because of the fibers

Strong because of the inorganic materials

43
Q

Two types of bone

A
  1. Compact

2. Spongy

44
Q

How is compact bone arranged?

A

in Osteons

45
Q

How is spongy bone arranged?

A

Arranged in trabeculae

46
Q

Osteoctyes communicate through ____

A

Canaliculi

47
Q

What do canaliculi do?

A

Radiate outward and connect one cell to the next cell in compact bone

48
Q

A unit of compact bone

A

Osteon

49
Q

Three structural components to osteons

A
  1. Concentric lamellae of matrix surrounding a central (Haversian) canal
  2. Contains blood vessels and nerves
  3. Osteons connected to each other by perforating canals
50
Q

Three different kinds of lamellae

A
  1. Concentric
  2. Interstitial
  3. Circumferential
51
Q
  • Layers of bone surrounding the central canal

- Make up osteons

A

Concentric lamellae

52
Q
  • Found between the osteons

- Represents older osteons partially removed during tissue remodeling

A

Interstitial lamellae

53
Q
  • Surrounded the compact bone

- Directly produced from periosteum

A

Circumferential

54
Q

What does spongy bone (cancellous) contain?

A
  • Trabeculae
  • Ostecytes in lacunae
  • Canaliculi
  • Matrix
55
Q

What does spongy bone not contain?

A

Osteons and central canal

56
Q

Latticework of thin plates of bone oriented along lines of stress

A

Trabeculae

57
Q

The spaces on trabeculae are filled with what?

A

Bone marrow where blood cells develop

58
Q

Where is trabeculae found?

A

Found in ends of long bones and inside flat bones

59
Q

What does trabeculae do?

A

Lightens the bone and allows for movement

60
Q

Encloses bone

A

Periosteum

61
Q

Where is periosteum absent?

A
  • Site of attachment of muscles, tendons, and ligaments

- Instead, surface are covered by articular cartilage

62
Q

Two layers of the periosteum and their respective jobs

A
  1. Outer fibrous: gives rise to collagen

2. Inner: for growth or new cells and maintenance

63
Q

One cell layer that covers surfaces of spongy bone and medullary cavity

A

Endosteum

64
Q

Cell types in the endosteum

A
  • Osteogenic, osteoblasts, and osteoclasts
65
Q

Five components to the anatomy of a long bone

A
  1. Diaphysis
  2. Epiphysis
  3. Metaphysis
  4. Articular cartilage
  5. Medullary cavity
66
Q

Shaft of a long bone

A

Diaphysis

67
Q

One end of a long bone

A

Epiphysis

68
Q

Growth plate region of a long bone

A

Metaphysis

69
Q

Over joint surfaces and acts as friction and shock absorber

A

Articular cartilage of a long bone

70
Q

Marrow cavity of a long bone

A

Medullary cavity

71
Q

Two types of bone marrow

A

Yellow and red

72
Q

Components to red bone marrow

A
  1. Areolar and myeloid tissue

2. Produces all types of blood cells

73
Q

Locations of red bone marrow

A

In medullary cavities of infants and in spongy bone in adults

74
Q

Four components to yellow bone marrow

A
  1. Composed of arelolar and adipose CT
  2. In medullary cavity of long bones
  3. Energy storage
  4. Absent in infants
75
Q

Supplies arteries with blood and nerve supply

A

Periosteal arteries

76
Q
  • Enter through nutrient foramen

- Supplies compact bone of diaphysis and yellow marrow

A

Nutrient arteries

77
Q

Nutrient arteries enter through _____

A

Nutrient foramen

78
Q

Supply red marrow and bone tissue of epiphyses and metaphyses

A

Metaphyseal and epiphyseal arteries

79
Q

All arteries have corresponding _____

A

Veins

80
Q

Replacing CT with bone

A

Ossification

81
Q

Mesenchymal cells -> spongy bone

A

Intramembranous

82
Q

Hyaline cartilage -> spongy bone

A

Endochondral

83
Q

When does intramembranous ossification begin and end?

A

Begins at about week 8 in embryo and finishes by week 15

84
Q

What does the intramembranous ossificiation form?

A
  • Cranial flat bone
  • Facial bones
  • Dentary bones
  • Clavicle
  • Sesmoid bones
85
Q

Location where bone growth begins

A

Primary ossification center

86
Q

Steps to intramembranous ossification

A
  1. Primary ossification center
  2. Mesenchymal cells arrange around blood vessels
  3. Bone morphogenic proteins released
  4. Mesenchymal cells are recruited, divided, and differentiated into osteoblasts
  5. osteoblasts secrete osteoid
  6. Osteoblasts become isolated and turn into osteocytes
  7. Produce spicules of bone that interconnect
  8. Mesenchymal cells at surface form inner layer of periosteum
  9. Calcified matrix is degraded by osteoclasts to form spongy bone
  10. End = spongy bone covered with thin layer of compact bone
87
Q

When bone replaces a cartilage model

A

Endochondral Ossification

88
Q

When does endochondral ossification begin?

A

Week 7 of embryo

89
Q

What does endochondral ossification

A
  • Long bones
  • Most short bones
  • Non-cranial irregular and flat bones
  • Middle ear ossicles
90
Q

Steps to endochondral ossification

A
  1. Hyaline cartilage forms model of future bone
  2. Cartilage enlarges; chondrocytes near center hypertrophy
  3. Blood vessels grow around and penetrate cartilage
  4. Cells differentiate into osteoblasts
  5. Compact bone forms around the diaphysis
  6. Spongy bone forms in the primary ossification center
  7. Remodeling of the shaft
  8. Formation of the medullary cavity
  9. Length increases
  10. Blood vessels penetrate the ends of the model
  11. Secondary ossification centers form at both epiphyses
  12. Ends with incomplete ossification of epiphysis
  13. Some cartilage remains
91
Q

What does it mean when the chondrocytes are near hypertrophy

A
  1. Matrix reduced to struts

2. Chondrocytes deprived of nutrients and die

92
Q

At the ends of endochondral ossification, what cartilage remains?

A
  1. Articular cartilage - contact points of bone

2. Epiphyseal plate - growth plate

93
Q

Explain the process of bone growth: elongation

A
  1. Occurs at epiphyseal plate
  2. Growth in length continues until 2 ossification centers meet
  3. Relative thickness of epiphyseal plate does not change until growth complete
  4. Cartilage depleted and epiphyseal plate narrows to epiphyseal line
94
Q

Explain bone growth: appositional

A
  1. Compact bone deposited beneath periostium
  2. Bone thickens
  3. Bone remodeling occurs throughout life (Due to osteoclasts and osteoblasts)
95
Q

Continual redistribution of bone matrix along lines of mechanical stress

A

Bone remodeling

96
Q

Why is bone remodeling ongoing?

A

Osteoclasts carve out small tunnels and osteoblasts rebuild osteons

97
Q

What percentage of bone is remodeled each year?

A

4% compact bone and 20% of spongy bone

98
Q

This bone is fully remodeled every 4 months

A

Distal femur

99
Q

Two types of fractures in bones with their meanings

A
  1. Closed (simple): break that does not penetrate skin

2. Open (compound): broken bone penetrates through skin

100
Q

Fractures are treated by ____ and ____

A

Reduction and immobilization

101
Q

Four ways for fractures to be repaired

A
  1. Fracture hematoma
  2. Fibrocartilage callus
  3. Bony callus
  4. Remodel tissue
102
Q

Factors affecting growth, repair, and development

A
  • Nutrition: Vit. D
  • Sunlight
  • Hormones: PTH, calcitonin, GH, thyroid hormone, sex hormones
  • Physical stress
103
Q

Abnormal reduction of bone mass

A

Osteoporosis

104
Q

Reasons for osteoporosis

A
  • Loss of estrogen at menopause
  • Deficiency of minerals in youth
  • Imbalance in activity between osteoblasts and osteoclasts
105
Q

Explain the illness of fibrodysplasia ossificant progressiva and its affect on the body and treatment plan

A
  • Fibrous tissue becomes ossified
  • Genetic
  • Injury results in inappropriate bone formation
  • Early adulthood: freezing of major joints
  • Early 20s: confined to wheel chair
  • Starvation and pneumonia can result
  • No treatment