Chapter 6 & 7 - Bone Tissue + Axial Skeleton Flashcards Preview

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Flashcards in Chapter 6 & 7 - Bone Tissue + Axial Skeleton Deck (109):
1

Distinguish between bone as a tissue and as an organ

bone is composed of several different tissues working together: bone, cartilage, dense connective, epithelium, adipose & nervous tissue 

therefore, each bone in your body is considered an organ 

2

Functions of Bone & Skeletal System (6)

1) support - structural framework

2) protection - protects internal organs

3) assistance in movement - skeletal muscle contract & pull on bones to produce movement

4) mineral homeostasis (storage & release) - bone tissue stores mineral 

5) blood cell production

6) triglyceride storage - yellow bone marrow consists of mainly adipose cells 

 

3

Structure of Bone (7) 

1) Diaphysis 

2) Epiphyses

3) Metaphyses

4) articular cartilage

5) periosteum

6) medullary (marrow) cavity

7) Endosteum

4

1) Diaphysis 

 

bone shaft or body

5

2) Epiphyses

 

proximal & distal ends of bone

6

3) Metaphyses

 

regions between diaphysis & epiphysis

contains epiphyseal (growth plate) 

when bone stops growing in length ,cartilage in epiphyseal plate is replaced by bone - epiphyseal line

7

4) articular cartilage

 

thin layer of hyaline cartilage covering part of epiphysis where bone forms an articulation (joint) with another bone

8

5) periosteum

 

 tough connective tissue sheath and its associated blood supply that surrounds bone surface wherever it is not covered by articular cartilage

outer fibrous layer &  inner osteogenic layer

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6) medullary (marrow) cavity

 

hollow, cylindrical space within diaphysis that contains fatty yellow bone marrow & humerus blood vessels in adults

10

7) Endosteum



 



 thin membrane that lines medullary cavity 



- contains a single layer of bone‐forming cells and small amount of connective tissue.



 

 

 

11

Like other connective tissues, bone (osseous tissue) congtains an abundant ..?

extracellular matrix that surronds widely separated cells 

12

Extracellular Matrix 

made up of?

15% water

30% collagen fibers

55% crystallized mineral salts

13

The most abundant mineral salt in bone is?

calcium phosphate

14

calcification

calcium phosphate combines with calcium hydroxide to form hydroxyapatite 

as crystals form, they combine with other mineral salts (calcium carbonate, Mg, F, K & sulfate ions) 

as these mineral salts are deposited & crystalzie in framework formed by collagen fibers of ECM

initiated by osteoblasts (bone-building cells)

15

Calcification is initiated by?

osteoblasts - bone-building cells

16

 Bone’s flexibility depends on?

collagen fibers

17

(4) types of cells present in bone tissue

1) osteogenic

2) osteoblasts 

3) osteocytes

osteoclasts 

18

osteogenic cells

Undergo cell division

the resulting cells develop into osteoblasts 

(unspecialized bone stem cells) 

19

osteoblasts

 Bone-building cells

synthesize extracellular matrix of bone tissue 

become osteocytes

20

Osteocytes

mature bone cells

exchange nutrients & wastes with blood

(main cells in bone, maintain daily metabolism)

21

Osteoclasts 

huge cells derived from fusion of as many as 50 monocytes  (type of white blood cell) 

 Release enzymes that digest the mineral components of bone matrix (resporption)

regulate blood calcium level

22

(2) categories of bone

1) compact

spongy

23

Compact bone

resists?

components?

these consist of?

 

Resists the stresses produced by weight and movement  Components of compact bone are arranged into repeating structural units called osteons (Haversian systems) 

 Osteons consist of a central (Haversian) canal

- run longitudinally through bone

- with concentrically arranged lamellae, lacunae, osteocytes, and canaliculi 

24

Lamellae

part of osteon, concentric lamallae are around central canals 

rings of calcified matrix (like rings of tree trunk)

25

Between the Lamellae are?

containing?

small spaces called lacunae which contain osteocytes

 

26

Canaliculi

what are they?

connect & form what?

purpose?

tiny canals radiating in all directions from lacunae, filled with extracellular fluid 

- connect lacunae & forming system of interconnected canals 

provides route for nutrients & oxygen to reach osteocytes

27

The organization of osteons changes in response to ?

the physical demands placed on the skeleton 

28

Spongy Bone

- makes up most interior bone tissue

- lacks osteons

lamellae are arranged  in a lattice of thin columns called trabeculae which contain spaces (make bones lighter) 

trabeculae support & protect red bone marrow

- oriented around lines of stress (helps bones resist stresses without breaking) 

29

hematopoiesis 

blood cell production

occurs in spongy bone

30

Lacunae in spongy bone

Lacunae are within each trabecula

contain osteocytes that are nourished from blood circulating through trabeculae

 

31

Bone is richly supplied with blood.

Where are blood vessels found in bone? 

especially abundant in portions of bone containing red bone marrow and pass into bones from periosteum. 

32

Periosteal arteries

accompanied by nerves

enter diaphysis through canals

supply the periosteum and compact bone 

33

Nutrient artery

passes through ole in compact bone (nutrient foramen) 

upon entering medullary cavity, divides into proximal & distal branches that supply inner part of compact bone tissue of diaphysis & spongy bone tissue & red bone marrow  

34

Veins that carry blood away from long bones 

1) nutrient veins (exit through diaphysis) 

2) epiphyseal & metaphyseal veins (exit through epiphyses) 

3) periosteal veins (exit through periosteum) 

35

Nerves accompany the blood vessels that supply bones. 

The ___ _is rich in sensory nerves sensitive to tearing or tension 

periosteum

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process by which bone is formed

ossification (osteogenesis) 

37

 Bone formation occurs in four situations: 

1) Formation of bone in an embryo

2) Growth of bones until adulthood

 3) Remodeling of bone 

4) Repair of fractures 

38

Formation of Bone in an Embryo

cartilage formation and ossification occurs during 6th week of embryonic development 

follows one of 2 patterns

39

(2) patterns of bone formation in an embryo

1) Intramembranous ossification

2) Endochondrial ossification

40

1) Intramembranous ossification

 

 

Flat bones of skull and mandible are formed in this way

-  “Soft spots” that help fetal skull pass through birth canal later become ossified forming skull 

1) develop ossification center - mesenchymal cells cluster at stop of bone development, differentiate into osteogenic then osteoblasts which secrete ECM

2) calcification - osteoblasts become osteocytes extend into canaliculi, mineral salts harden 

3) formation of trabeculae - as ECM forms it develops into trabeculaw that fuse together around network of blood vessels in tissue (connective tissue associated with blood veseels differentiates into red bone marrow)

4) development of periosteum 

41

2) Endochondrial ossification

The replacement of cartilage by bone

Most bones of the body are formed in this way including long bones 

1) development of cartilage model - mesenchymal cells develop into chondroblaste that secrete cartilage ECM 

2) growth of cartilage model - chondroblasts become deeply buried in ECM (chondrocytes) 

3) development of primary ossification center 

4) development of medullary cavity

5) development of 2ndary ossification centers

6) formation of articular cartilage & epiphyseal (growth) plate)  

42

Bone Growth During Infancy, Childhood and Adolescence 

bones throughout body grow in thickness by appositional growth - deposition of ECM on cartilage surface of model by new chondroblasts that develop from perichondrium 

long bones lengthen by addition of bone material on diaphyseal side of epiphyseal plate by interstitial growth (endogenous)

43

Growth in Length of long bones involves (2) major events

1) interstitial growth of cartilage on epiphyseal side of epiphyseal plate

2) replacement of cartilage on diaphyseal side of epiphyseal plate by bone tissue

44

Growth in Length

osteoclasts dissolve the calcified cartilage, and osteoblasts invade area laying down bone matrix  (replacing calcified cartilage) 

activity of the epiphyseal plate is the way bone can increase in length

At adulthood, the epiphyseal plates close and bone replaces all cartilage leaving a bony structure called the epiphyseal line 

45

Growth in Thickness

Bones grow in thickness at the outer surface (appositional growth) 

as new bone is deposited on outer surface of bone by osteoblasts, bone tissue lining medullary cavity is destroyed by osteoclasts in endosteum

46

 Remodeling of Bone 

 Bone forms before birth and continually renews itself

 ongoing replacement of old bone tissue by new bone tissue

involves bone resorption - removal of mineral & collagen fibers from bone by osteoclasts

bone deposition - addition of mineral & collagen fibers to bone by osteoblasts 

47

The human skeleton consists of _________named bones 

206

48

Bones of the skeleton are grouped into (2) principal divisions: 

1) Axial skeleton

2) Appendicular skeleton

49

Axial Skeleton

Consists of  bones that lie around the longitudinal axis of the human body

Skull bones, auditory ossicles (ear bones), hyoid bone, ribs, sternum (breastbone), & bones of  vertebral column

50

Appendicular Skeleton

Consists of the bones of the upper and lower limbs (extremities), plus the bones forming the girdles that connect the limbs to the axial skeleton  

51

Bones can be classified into (5) types based on shape

1) long

2) short

3) flat

4) irregular

5) sesamoid

52

Long Bones

Greater length than width and are slightly curved for strength

 

Femur, tibia, fibula, humerus, ulna, radius, phalanges  

53

Short Bones

cube-shaped & are nearly equal in length & width

Carpal, tarsal 

54

Thin Bones

Thin and composed of two nearly parallel plates of compact bone tissue enclosing a layer of spongy bone tissue 

Cranial, sternum, ribs, scapulae  

55

Irregular Bones

complex shapes & cannot be grouped into any of the previous categories

Vertebrae, hip bones, some facial bones, calcaneus 

56

Sesamoid Bones

 Protect tendons from excessive wear and tear

 Patellae, foot, hand 

57

Sutural Bones

classified by location rather than shape

small bones located in sutures of cranial bones

58

Bone Surface Markings 

Structural features adapted for specific functions 

59

(2) major types of surface markings: 

1) depressions & openings

2) processes

60

1) depressions & openings 

 

Allow the passage of blood vessels and nerves or form joints 

61

2) processes 

Projections or outgrowths that form joints or serve as attachment points for ligaments and tendons 

62

Skull (cranium) consists of ___ bones

22

63

Bones of skull are grouped into (2) categories 

1) Cranial bones

2) Facial bones

64

1) Cranial bones

how many?

what do they form?

what are they?

8 cranial bones form cranial cavity

frontal bone, 2 parietal bones, 2 temporal bones,  occipital bone, sphenoid bone, ethmoid bone 

65

2) Facial Bones

14 facial bones form face

2 nasal bones, 2 maxillae, 2 zygomatic, mandible, 2 lacrimal, 2 palatine, 2 inferior nasal conchae, vomer

66

The cranial and facial bones protect and support special sense organs and the brain.

Besides the cranial cavity, the skull also forms (4) small cavities 

1) nasal 

2) orbits

3) paranasal sinuses

4) middle ear cavities 

67

Sutures

immovable joints that fuse most of the skull bones together 

68

Skull and facial bones provide _______________for muscles that produce facial expressions

The facial bones form the ____ of the face and provide __ for the entrances to the ____ and ____ systems 

attachment

framework 

support 

digestive

respiratory 

 

69

Frontal Bone

forms forehead

70

Parietal Bones

form sides & roof of cranial cavity

71

Temporal Bones

Form the lateral aspects and floor of the cranium 

72

Occipital Bone

Forms the posterior part and most of the base of the cranium 

73

Sphenoid Bone

Lies at the middle part of the base of the skull

74

Ethmoid Bone

located?

major supporting structure of?

contains?

Located on midline in anterior part of cranial floor medial to the orbits

major superior supporting structure of the nasal cavity

Contain thin projections called conchae which are lined by mucous membranes

Increased surface area in the nasal cavity helps to humidify inhaled air trapping inhaled particles 

75

Nasal Bones

forms bridge of nose

76

Maxillae

form upper jawbone & most of hard palate

seperates  nasal cavity from oral cavity 

 

77

Zygomatic Bones

cheekbones

form prominence of cheeks

78

Lacrimal Bones

form part of medial wall of each orbit

79

Palatine Bone

posterior portion of hard palate 

80

Inferior Nasal Conchae

form part of inferior lateral wall of nasal cavity

81

Vomer

forms inferior portion of nasal septum

 

82

Mandible

lower jawbone

largest strongest facial bne

only movable skull bone

83

Nasal Septum

Divides interior of the nasal cavity into right and left sides

 “Broken nose,” in most cases, refers to septal damage rather than the nasal bones themselves 

84

Orbit

eye socket

85

Foramina

Openings for blood vessels , nerves , or ligaments of the skull 

86

Unique Features of the Skull 

sutures paranasal sinuses, fontanels

87

Paranasal Sinuses 

Cavities within cranial & facial bones near nasal cavity

 Secretions produced by mucous membranes which line the sinuses, drain into the nasal cavity

Serve as resonating chambers that intensify and prolong sounds 

88

Fontanels

areas of unossified mesenchyme tissue that develops into dense connective tissue of skull 

"soft spots" that link cranial bones

eventually replaced with bone to become sutures

provide flexibility to fetal skull, allowing the skull to change shape as it passes through the birth canal 

89

Hyoid Bone

does not articulate with any other bone

supports tongue, providing attachment sites for some tongue muscles and for muscles of the neck and pharynx

helps to keep larynx (voice box) open at all times

90

Vertebral Column (spine, backbone, spinal column) 

functions to?

Protect the spinal cord

Support the head

Serve as a point of attachment for the ribs, pelvic girdle, and muscles 

91

vertebral column is curved to varying degrees in different locations 

why?

to increase column strength

help maintain balance in upright position

absorbs shocks when walking

help protect vertebrae from fracture

 

92

(3) conditions that may exagerate normal curve of vertebral column

1) kyphosis - forward curve

2) lordosis - backward curve

3) scoliosis - sideways 

93

Vertebral Column is composed of?

a series of bones called vertebrae

(26 in adults) 

94

Components of Vertebral Column

 

7 cervical vertebrae in neck region

12 thoracic vertebrae posterior to thoracic cavity

 5 lumbar vertebrae support lower back

1 sacrum consists of 5 fused sacral vertebrae

1 coccyx consists of 4 fused coccygeal vertebrae 

95

Intervertebral Discs 

found?

 Found between the bodies of adjacent vertebrae 

 

96

Intervertebral Discs 

function to?

Form strong joints

Permit various movements of the vertebral column

Absorb vertical shock

97

Vertebrae typically consist of (3) 

1) vertebral body (weight bearing)

2) vertebral arch (surrounds spinal cord) 

3) several processes (points of attachment for muscles) 

98

Regions of the Vertebral Column

1) cervical region

2) thoracic region

3) lumbar region

4) sacrum 

5) coccyx 

99

Cervical Region

Cervical Vertebrae (C1-C7) 

 The atlas (C1) is the 1st cervical vertebra

 The axis (C2) is the 2nd cervical vertebra 

 

100

Thoracic Region

Thoracic Vertebrae (T1-T12)

Articulate with the ribs 

101

Lumbar Region

 Lumbar vertebrae (L1–L5)

Provide for attachment of the large back muscles

102

Sacrum

a triangular bone formed by union of 5sacral vertebrae (S1–S5)

-  Serves as a strong foundation for the pelvic girdle 

103

Coccyx

like the sacrum, triangular in shape

formed by fusion of 4 coccygeal vertebrae

104

Thorax (entire chest region) 

Thoracic Cage (skeletal part of thorax) is formed by?

sternum

ribs 

costal cartilages

thoracic vertebrae

105

Thorax functions to?

 Enclose and protect the organs in the thoracic and abdominal cavities

 Provide support for the bones of the upper limbs

Play a role in breathing 

106

Sternum

location?

consists of?

 “Breastbone” located in the center of the thoracic wall

 Consists of the manubrium, body, xiphoid process 

107

Ribs

 12 pairs of ribs give structural support to the sides of thoracic cavity 

108

Costal Cartilages 

 contribute to the elasticity of the thoracic cage 

109