Ch. 6: Bones And Skeletal Tissues

Front 1

Dense irregular connective tissue that surrounds skeletal cartilage and resists outward expansion

Back 1

perichondrium

Front 2

What are the three types of skeletal cartilage?

Back 2

hyaline, elastic, fibrocartilage

Front 3

Does skeletal cartilage contain blood vessels or nerves?

Back 3

No

Front 4

A skeletal cartilage that provides support, flexibility, and resilience; most abundant

Back 4

hyaline

Front 5

Where is hyaline cartilage found?

Back 5

articular: ends of long bones

costal: connects ribs to sternum

respiratory: makes up larynx, reinforces air passages

nasal: supports the nose

Front 6

A skeletal cartilage similar to hyaline cartilage but contains elastic fibers

Back 6

elastic cartilage

Front 7

Where is elastic cartilage found?

Back 7

external ear and epiglottis

Front 8

A skeletal cartilage that is highly compressed with great tensile strength; contains collagen fibers

Back 8

fibrocartilage

Front 9

Where is fibrocartilage found?

Back 9

menisci of knee and in intervertebral discs

Front 10

When cells in the perichondrium secrete matrix against the external face of existing cartilage

Back 10

appositional growth

Front 11

When lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within

Back 11

interstitial growth

Front 12

Calcification of cartilage occurs when?

Back 12

during normal bone growth

during old age

Front 13

What is included in the axial skeleton?

Back 13

skull, vertebral column, rib cage

Front 14

What is included in the appendicular skeleton?

Back 14

bones of the upper and lower libs, shoulder, hip

Front 15

Bones that are longer than they are wide

Back 15

long bones

Front 16

Bones from within tendons or cube-shapedbones found within the wrist and ankle

Back 16

short bones

Front 17

Bones that are thin, flattened, and a bit curved

Back 17

flat bones

Front 18

Bones with complicated shapes

Back 18

irregular bones

Front 19

What are the five functions of bone?

Back 19

1. support

2. protection

3. movement - act as levers for muscles

4. mineral storage - especially Ca and P

5. blood cell formation

Front 20

Rounded projection on a bone

Back 20

tuberosity

Front 21

A narrow, prominent ridge of bone

Back 21

crest

Front 22

A large, blunt, irregular surface on a bone

Back 22

trochanter

Front 23

A narrow ridge of bone

Back 23

line

Front 24

A small rounded projection on bone

Back 24

tubercle

Front 25

A raised area above a condyle on bone

Back 25

epicondyle

Front 26

A sharp, slender projection on a bone

Back 26

spine

Front 27

Any bone prominence

Back 27

process

Front 28

A bony expansion of the bone carried on a narrow neck

Back 28

head

Front 29

A smooth, nearly flat articular surface on a bone

Back 29

facet

Front 30

A rounded articular projection on a bone

Back 30

condyle

Front 31

An armlike bar of bone

Back 31

ramus

Front 32

A canal-like passageway on a bone

Back 32

meatus

Front 33

A cavity within a bone

Back 33

sinus

Front 34

A shallow, basin-like depression on a bone

Back 34

fossa

Front 35

A furrow on a bone

Back 35

groove

Front 36

A narrow, slit-like opening on a bone

Back 36

fissure

Front 37

A round or oval opening through a bone

Back 37

foramen

Front 38

The dense outer layer of bone

Back 38

compact bone

Front 39

The honeycomb of trabeculae filled with yellow bone marrow

Back 39

spongy bone

Front 40

A tubular shaft that forms the axis of long bones; composed of compact bone surrounding a medullary cavity containing yellow bone marrow

Back 40

diaphysis

Front 41

Where the growth plate lies; found between the diaphysis and epiphysis

Back 41

metaphysis

Front 42

The expanded ends of long bones; exterior is compact while the interior is spongy bone; joint surface is covered with hyaline cartilage

Back 42

epiphysis

Front 43

Separates the diaphysis and epiphysis

Back 43

epiphyseal line

Front 44

A double-layered protective membrane that surrounds bones

Back 44

periosteum

Front 45

The outer fibrous layer of the periosteum is ____________ and the inner osteogenic layer is compose of ____________.

Back 45

dense regular connective tissue

osteoblasts and osteoclasts

Front 46

The periosteum is richly supplied with ______, ______, and __________ which enter the bone via _____________. It's secured to underlying bone by __________.

Back 46

nerve fibers

blood

lymphatic vessels

nutrient foramina

Sharpey's fibers

Front 47

A delicate membrane covering the internal surfaces of bone

Back 47

endosteum

Front 48

What is different about short/irregular/flat bones vs. long bones?

Back 48

1. they are made up of periosteum-covered compact bone on the outside and endosteum-covered spongy bone (diploe) on the inside

2. they have no diaphysis or epiphysis

3. they contain bone marrow between the trabeculae

Front 49

Where is hematopoietic tissue found in infants?

Back 49

in the medullary cavity and all areas of spongy bones

Front 50

Where is hematopoietic tissue found in adults?

Back 50

in the diploe of flat bones and the head of the femur and humerus

Front 51

What is the structural unit of compact bone?

Back 51

Haversian system or osteon

Front 52

Weight-bearing, column-like matrix tubes composed mainly of collagen

Back 52

lamella

Front 53

Central channel containing blood vessels or nerves

Back 53

Haversian/central canal

Front 54

Channels lying are right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal

Back 54

Volkmann's canals

Front 55

mature bone cells

Back 55

osteocytes

Front 56

small cavities in bone that contain osteocytes

Back 56

lacunae

Front 57

hair-like canals that connect lacunae to each other and the central canal

Back 57

canalicuni

Front 58

bone-forming cells

Back 58

osteoblasts

Front 59

large cells that reabsorb or break down bone matrix

Back 59

osteoclasts

Front 60

unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen

Back 60

osteoid

Front 61

mineral salts

Back 61

hydroxyapatites

Front 62

Hydroxyapetites make up ____% of bone by mass and are composed of mainly _________. They are responsible for the bone's ________ and ________.

Back 62

65

calcium phosphates

hardness

resistance to compression

Front 63

The process of bone tissue formation that leads to formation of bony skeleton in embryos, bone growth until early adulthood, and bone thickness, remodeling and repair

Back 63

osteogenesis and ossification

Front 64

The formation of bony skeleton begins at week ___ of embryo development.

Back 64

8

Front 65

When bone develops from a fibrous membrane via mesenchymal cells; forms most of flat bones of skull and clavicles

Back 65

intramembranous ossification

Front 66

When bone forms by replacing hyaline cartilage

Back 66

endochondral ossification

Front 67

What are the stages of intramembranous ossification?

Back 67

1. An ossification center appears in the fibrous connective tissue membrane from locally differentiated mesenchymal cells.

2. Bone matrix (osteoid) is secreted within membrane via osteoblasts.

3. Osteoid is mineralized within a few days, trapped osteoblasts become osteocytes.

3. Woven bone and periosteum form - vascularized mesenchyme condenses on the external face of the woven bone.

4. Bone collar of compact bone forms, and red marrow appears

Front 68

Endochondral ossification begins in the _____ month of development. It uses ___________ "bones" as models for bone construction. It requires the _______________ prior to ossification.

Back 68

2nd

hyaline cartilage

breakdown of hyaline cartilage

Front 69

What are the stages of endochondral ossification?

Back 69

1. Formation of bone collar

2. Cavitation of hyaline cartilage

3. Invasion of internal cavities by the periosteal bud, and spongy bone formation

4. Formation of the medullary cavity; appearance of secondary ossification centers in the epiphysis

5. Ossification of the epiphysis, with hyaline cartilage remaining only in the epiphyseal plates

Front 70

Cartilage on the side of the epiphyseal plate closest to the epiphysis is relatively ______.

Back 70

inactive

Front 71

Cartilage abutting the shaft of the bone organizes into a pattern that _____________.

Back 71

allows fast, efficient growth.

Front 72

The zone in which cartilage cells undergo mitosis, pushing the epiphysis away from the diaphysis

Back 72

growth zone

Front 73

The zone where older cells enlarge, the matrix becomes calcified, cartilage cells die, and the matrix begins to deteriorate

Back 73

transformation (or hypertrophic and calcification) zone

Front 74

The zone where new bone formation occurs

Back 74

osteogenic zone

Front 75

cartilage continually grows and is replaced by bone

Back 75

growth in length

Front 76

bone is reabsorbed and added by appositional growth

Back 76

remodeling

Front 77

During childhood and infancy, epiphyseal plate activity is stimulated by _____.

Back 77

growth hormone

Front 78

What are the roles of testosterone and estrogens in bone growth?

Back 78

During puberty:

1. promote growth spurts

2. cause masculinization and feminization of specific parts of the skeleton

3. later induce the epiphyseal plate closure, ending growth

Front 79

Adjacent osteoblasts and osteoclasts that deposit and reabsorb bone at periosteal and endosteal surfaces

Back 79

remodeling units

Front 80

Bone deposition occurs when bone is _____ or added _____ is needed. It requires a diet rich in ______, vitamins __, __, and __, _____, _____, magnesium, and manganese.

Back 80

injured

strength

protein

C

D

A

calcium

phospherus

Front 81

_____________ is essential for mineralization of bone.

Back 81

alkaline phosphatase

Front 82

Sites of new matrix deposition are revealed by ______ and _______.

Back 82

osteoid seam and calcification front

Front 83

unmineralized band of bone matrix

Back 83

osteoid seam

Front 84

abrupt transition zone between the osteoid seam and the older mineralized bone

Back 84

calcification front

Front 85

Bone reabsorption is accomplished by ______.

Back 85

osteoclasts

Front 86

Grooves formed by osteoclasts as they break down bone matrix

Back 86

reabsorption bays

Front 87

Reabsorption includes osteoclast secretion of ________ that digest organic matrix and ______ that convert calcium salts into soluble forms.

Back 87

lysosomal enzymes

acids

Front 88

dissolved matrix is transcytosed across the osteoclast's cell where it is secreted into the interstitial fluid and then into the blood

Back 88

bone reabsorption

Front 89

Calcium is necessary for which five things?

Back 89

1. transmission of nerve impulses

2. muscle contraction

3. blood coagulation

4. secretion by glands and nerve cells

5. cell division

Front 90

Which two control loops regulate bone remodeling?

Back 90

1. hormonal mechanism that maintains calcium homeostasis in the blood

2. mechanical and gravitational forces acting on the skeleton

Front 91

What are the steps in the hormonal regulation of bone remodeling?

Back 91

1. rising blood calcium levels trigger the thyroid to release calcitonin

2. calcitonin stimulates calcium salt deposit in bone

3. falling calcium levels signal the parathyroid glands to release PTH

4. PTH signals osteoclasts to degrade bone matrix and release calcium into the blood

Front 92

The ________ gland makes PTH.

Back 92

parathyroid

Front 93

A bone grow or remodels in response to the forces or demands placed upon it

Back 93

Wolff's law

Front 94

What observations support Wolff's law?

Back 94

1. long bones are thickest midway along the shaft (where bending stress is greatest)

2. curved bones are thickest where they are most likely to buckle

Front 95

What happens in response to mechanical stress?

Back 95

1. trabeculae form along lines of stress

2. large, bony projections occur where heavy, active muscles attach

Front 96

What four things are bone fractures classified by?

Back 96

1. the position of bone ends after fracture

2. the completeness of the break

3. the orientation of the bone to the long axis

4. whether or not the bone's ends penetrate the skin

Front 97

A type of fracture where bone ends retain their normal position

Back 97

nondisplaced

Front 98

A type of fracture where bone ends are out of normal alignment

Back 98

displaced

Front 99

A type of fracture where bone is broken all the way through

Back 99

complete

Front 100

A type of fracture where bone is not broken all the way through

Back 100

incomplete

Front 101

A type of fracture where the fracture is parallel to the long axis of the bone

Back 101

linear

Front 102

A type of fracture where the fracture is perpendicular to the long axis of the bone

Back 102

transverse

Front 103

A type of fracture where bone ends penetrate the skin

Back 103

compound (open)

Front 104

A type of fracture where bone ends do not penetrate the skin

Back 104

simple (closed)

Front 105

A type of fracture where bone fragments into three or more pieces; common in elderly

Back 105

comminuted

Front 106

A type of fracture where there is a ragged break when bone is excessively twisted; common sports injury

Back 106

spiral

Front 107

A type of fracture where broken bone portion is pressed inward; typical skull fracture

Back 107

depressed

Front 108

A type of fracture where bone is crushed; common in porous bones

Back 108

compression

Front 109

A type of fracture where the epiphysis separates from the diaphysis along the epiphyseal line; occurs where cartilage cells are dying

Back 109

epiphyseal

Front 110

A type of incomplete fracture where one side of the bone breaks and the other side bends; common in children

Back 110

greenstick

Front 111

What happens in the "hematoma formation" stage of healing a bone fracture?

Back 111

-torn blood vessels hemorrhage

-a mass of clotted blood forms

-site becomes swollen, painful, and inflamed

Front 112

What happens in the "fibrocartilaginous callus formation" stage of healing a bone fracture?

Back 112

-fibrocartilaginous callus forms

-granulation tissue (soft callus) forms a few days later

-capillaries grow into the tissue and phagocytic cells begin cleaning debris

Front 113

How does the fibrocartilaginous callus form?

Back 113

1. osteoblasts and fibroblasts migrate to the fracture and begin reconstructing the bone

2. fibroblasts secrete collagen fibers that connect broken bone ends

3. osteoblasts begin forming spongy bone

4. osteoblasts furthest from capillaries secrete an externally bulging cartilaginous matrix that later calcifies

Front 114

What happens in the "bony callus formation" stage of healing a bone fracture?

Back 114

-new bone trabeculae appear in the fibrocartilaginous callus

-fibrocartilaginous callus converts into a bony callus

-bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later

Front 115

What happens in the "bone remodeling" stage of healing a bone fracture?

Back 115

-excess material on the bone shaft exterior and in the medullary canal is removed

-compact bone is laid down to reconstruct shaft walls

Front 116

When bones are inadequately mineralized causing softened, weakened bones; main symptoms is pain when weight is put on the affected bone

Back 116

osteomalacia

Front 117

What is osteomalacia caused by?

Back 117

insufficient calcium in the diet or vitamin D deficiency

Front 118

When bones of children are inadequately mineralized causing softened, weakened bones; characterized by bowed legs and deformities of the pelvis, skull, and rib cage

Back 118

Rickets

Front 119

What is Rickets caused by?

Back 119

insufficient calcium in the diet or vitamin D deficiency

Front 120

A group of diseases in which bone reabsorption outpaces bone deposit; spongy bone of the spine is most vulnerable; most often occurs in menopausal women; bones become so fragile that sneezing or stepping off a curb can cause fractures

Back 120

osteoporosis

Front 121

How is osteoporosis treated?

Back 121

-calcium and vitamin D supplements

-increased weight-bearing exercise

-hormone (estrogen) replacement therapy slows bone loss

-natural progesterone cream promotes new bone growth

-statins increase bone mineral density

Front 122

A disease characterized by excessive bone formation and break down; bone with an excessively high ratio of woven to compact bone is formed; reduced mineralization causes spotty weakening of bone

Back 122

Paget's disease

Front 123

In Paget's disease, ______ activity wanes while ______ activity continues to work.

Back 123

osteoclast

osteoblast

Front 124

Where is Paget's disease usually localized?

Back 124

spine, pelvis, femur, skull

Front 125

What is the cause of Paget's disease and what are the available treatments?

Back 125

Cause: unknown

Treatments: drugs (Didronate and Fosamax)