Hsf: Cartilage And Bone

Front 1

Function of Cartilage

Back 1

-Provides...
~Flexible support
~Smooth, tough articular surfaces for joints

Front 2

During development, the fetal skeleton has bone models of ______ cartilage.

Back 2

Hyaline

Front 3

List the types of Cartilage (3)

Back 3

-Hyaline
-Elastic
-Fibrocartilage

Front 4

Hyaline Cartilage (def)

Back 4

-Forms articulating surface of most bones, tracheal rings, nasal and laryngeal cartilages
-Forms the cartilage models of bones in the fetus

Front 5

Where is Elastic Cartilage found?

Back 5

-Found in the epiglottis, the external ear and the ear canal

Front 6

Fibrocartilage: What does is it form?

Back 6

-Part of intervertebral disks
-Some of the symphyses
-Some tendonous insertions into the bone
-Eustachian tube

Front 7

General structure of connective tissue, cartilage is made up of...

Back 7

-Cells in an extracellular matrix

Front 8

_______ are the primary cells of cartilage. They reside within the matrix in ______.

Back 8

-Chondrocytes
-Lucanae

Front 9

What is the extracellular matrix made up of?

Back 9

-Collagen fibers (type II for hyaline and elastic, type I for fibrocartilage)
-Ground Substance

Front 10

What makes up ground substance?

Back 10

-Proteoglycans: composed primarily of the glycosaminoglycans condroitin-4-4 and condroitin-6-sulfate

Front 11

Elastic cartilage has large amounts of _____ fiber within the matrix.

Back 11

Elastic

Front 12

What does perichondrium surround?

Back 12

Hyaline and Elastic Cartilage

Front 13

Perichondrium (def)

Back 13

-Dense Connective Tissue Sheath

Front 14

True or False: Cartilage is vascular, and contains no nerves.

Back 14

False, Cartilage is AVASCULAR, and contains NO nerves.

Front 15

How does cartilage receive all it nutrients?

Back 15

-By diffusion through the matrix from the blood vessels in the surrounding connective tissue

Front 16

Cartilage differentiates from ______.

Back 16

-Mesenchyme

Front 17

Mesenchymal cells differentiate into _________ ,which begin to lay down cartilage matrix around them.

Back 17

-Chondroblasts

Front 18

When are chondroblasts known as chondrocytes?

Back 18

-When the cells become surrounded by matrix

Front 19

What is an isogenous nest?

Back 19

-When several cells occupy the same lucana during cell division within a matrix.

Front 20

Interstitial Growth (def)

Back 20

-Growth occurring within the cartilage
-Happens after cells lay down matrix

Front 21

Mesenchyme surrounding the cartilage differentiates into what?

Back 21

-Dense connective tissue (PERICHONDRIUM)

Front 22

________ form at the inner edge of the perichondrium and can add cartilage to that surface.

Back 22

-Chondroblasts

Front 23

Functions of Bone

Back 23

-Provides strong, rigid support and protection
-Storage site for calcium and phosphorus
-Contains marrow cavity

Front 24

What does the marrow cavity contain?

Back 24

-Hematopoietic tissue that is the source of both red and white blood cells

Front 25

What makes up the structure of bone?

Back 25

-Cells: Osteocytes
-Extracellular Matrix

Front 26

Bone:The extracellular matrix has a very high ____ content (65%), consisting largely of _______ crystals that contain calcium and phosphorus.

Back 26

-Mineral
-Hydroxyapatite Crystals

Front 27

What kind of collagen is found in bone?

Back 27

-Mostly Type I Collagen

Front 28

The ground substance of bone contains __________, and special ________ and ________ that help bind calcium during mineralization.

Back 28

-Glycosaminoglycans
-Glycoproteins
-Sialoproteins

Front 29

2 Types of Mature Bone Tissue

Back 29

-Compact
-Cancellous

Front 30

Compact Bone (def)

Back 30

-The dense layer that forms the outside of bone

Front 31

Cancellous Bone (def)

Back 31

-The meshwork of thin trabeculae or spicules on the interior of bone
-Also called spongy bone

Front 32

In mature bone, the cells are arranged in layers called ______.

Back 32

Lamellae

Front 33

Another name for mature bone

Back 33

-Lamellar bone

Front 34

All bone is highly ______ and surrounded by a dense irregular connective tissue sheath called ________.

Back 34

-Vascular
-Periosteum

Front 35

What lines the inside surface of bone?

Back 35

-Endosteum

Front 36

Osteoprogenitor Cells (def)

Back 36

-Cells of mesenchymal origin that replicate and differentiate into osteoblasts
-When inactive, the are the bone-lining of the endosteum and periosteum

Front 37

Osteoblasts (def)

Back 37

-Cells that synthesize and secrete bone matrix (osteoid) on growing surfaces
-Matirx is then mineralized under the regulation of the osteoblast which secretes calcium-phosphorus vesicles into the extracellular matirx

Front 38

Osteocytes (def)

Back 38

-osteoblasts becomes surrounded by mineralized matrix=osteocyte
-have limited ability to synthesize and resorb bone, helping to maintain blood calcium homeostasis

Front 39

Osteoclasts (def)

Back 39

-Multinucleated phagocytic cell derived from bone marrow
-Break down calcified matrix by lysosomal action which digests collagen (using collagenase) and minerals (using acid)

Front 40

Compact bone is formed by columns called ____ _____ or _____

Back 40

-Haversian systems
-Osteons

Front 41

Osteons are formed by concentric _______ that surround a core (Haversian canal) containing ______ ______ and _____.

Back 41

-Lamellae
-Blood vessels
-Nerves

Front 42

Volkmann's Canals (def)

Back 42

-Oblique channels that interconnect Haversian canals that contain blood vessels and nerves
-Allow for distribution of nerves and blood vessels from the periosteal surface to the endosteal surface and throughout the bone

Front 43

The layers of the osteon are formed by _______ in the lacunae, arranged in circles with calcified matrix between them.

Back 43

-Osteocytes

Front 44

Connection between osteocytes is formed via....?

Back 44

-Gap Junctions and fine osteocyte fine fiber processes

Front 45

The osteocyte fine fiber processes lie in small tunnels within a matrix, called ______.

Back 45

-Canaliculi

Front 46

Canaliculi (Def)

Back 46

-allow for the diffusion of substances from the Haversian canal into the lucanae in more distant layers of the osteon

Front 47

True or False: The inside and outside layers of the compact bone are lamellar (inner and outer circumferential lamellae).

Back 47

True

Front 48

Bone is constantly being _______ and re-formed in a process called ______.

Back 48

-Resorbed
-Remodeling

Front 49

Bone is resorbed by _____ that resorb bone from surfaces.

Back 49

-Osteoclasts

Front 50

Appositional Growth (Def)

Back 50

-Reforms bone on pre-existing bone surfaces by osteoblasts

Front 51

What is osteoclasts role in bone remodeling?

Back 51

-They cut resorption canals through pre-existing bone

Front 52

What happens after osteoclasts cut canals in pre-existing bone?

Back 52

-They are filled from the outside in by osteoblasts laying down new lamellae

Front 53

The remains of old Haversian systems are seen as the _______ _______ between new systems.

Back 53

-Interstitial lamellae

Front 54

Osteoblasts differentiate from the ______ and _______ cells that line all bone surfaces not undergoing remodeling.

Back 54

-Periosteal
-Endosteal

Front 55

What does osteoblast secrete?

Back 55

-Osteoid

Front 56

What is osteoid made of?

Back 56

-Collagen and Ground Substance of unmineralized bone

Front 57

The osteoblast secretes small matrix vesicles rich in _______ ________.

Back 57

-Alkaline Phosphatase

Front 58

What are the effects of alkaline phosphatase in bone?

Back 58

-Increases local PO4- concentrations-->which increases Ca2+ concentrations= results in deposition of hydroxyapatite crystals
-Mineralization of the initial site causes a wave of mineralization throughout the osteoid

Front 59

2 Processes of Bone Formation during Fetal Development

Back 59

-Intramembranous Ossification
-Endochondral Ossification

Front 60

Intramembranous Ossification (def)

Back 60

-forming flat bones of the skull, face, mandible, and clavicle
-Occurs during fetal development

Front 61

Endochondrial Ossification

Back 61

-Forming the bones of the axial skeleton and the extremities
-Occurs during fetal development

Front 62

During fetal development, ossification centers for flat bones, particularly those of the skull, form within _____.

Back 62

-Mesenchyme

Front 63

4 Occurrences During Intramembranous Ossification (Fetal Development)

Back 63

-Mesenchymal cells differntiate into osteoblasts(=blastema), which secrete osteoid in a pattern called woven bone
-Osteoid becomes calcified
-Other mesenchyme is differentiating into the hematopoietic tissue that will form the bone marrow
-Immature, woven bone is gradually remodeled into lamellar bone

Front 64

During fetal development, ______ cartilage models form by much the same process intramembranous bone.

Back 64

-Hyaline

Front 65

How does hyaline cartilage model form during fetal development?

Back 65

-Chondroblasts differentiate from mesenchyme and begin to lay down matrix.

Front 66

What are formed from the hyaline cartilage model?

Back 66

-Bones of the axial skeleton and the limbs
-These models are them replaced with bone

Front 67

What does the process of endochondrial ossification give rise to? And what does it do?

Back 67

-the Epiphyseal plate which permits extensive and rapid lengthening of the long bones.

Front 68

Endochondrial Ossification Summary: (1) Cartilage model is formed from ________, _______ the shape that the bone will have, and continues to grow by proliferation of _________ and ________ _______.

Back 68

-Mesenchyme
-Develops
-Chondrocytes
-Interstitial Growth

Front 69

Endochondrial Ossification: (2) Cartilage growth reaches size at which ......

Back 69

-Nutrients provide adequate nutrition by diffusion (cartilage is avascular)

Front 70

Endochondrial Ossification: (3) The oldest, most poorly nourished cells first ________, then _______.

Back 70

-Hypertrophy
-Degenerate

Front 71

Endochondrial Ossification: (4) The surrounding cartilage matrix becomes _______.

Back 71

-Calcified

Front 72

Endochondrial Ossification: (5) A bone collar is formed by ________/________ cells that differentiate into ________.

Back 72

-Perichondrial/periosteal cells
-Osteoblasts

Front 73

Endochondrial Ossification: (6)The _____ _______ is penetrated by the nutrient artery, which bring it ________ _____, the forming ________ tissuem and ________.

Back 73

-Bone Collar
-Osteoprogenitor Cells
-Hematopoietic tissue
-Osteoclasts

Front 74

Endochondrial Ossification: (7) ________ remove some of the calcified cartilage, and begin forming the marrow cavity, allowing more _______ development.

Back 74

-Osteoclasts
-Vascular

Front 75

Endochondrial Ossification: (8a)______ (derived from the incoming osteoprogenitor cells) lay down ______ on the calcified cartilage, which become mineralized.

Back 75

-Osteoblasts
-Osteoid

Front 76

Endochondrial Ossification: (8b) Growth continues by _______ of new bone on pre-existing bone.

Back 76

-Apposition

Front 77

Endochondrial Ossification: (8c) The bone collar is gradually repleced by ________ _______, complet _______ systems.

Back 77

-Adult bone
-Haversian Systems

Front 78

Epiphyseal Plate (def)

Back 78

-Growth continues at the ends of long bones because the specialized cartilage of the epiphyseal plate continues to grow by chondroblast proliferation and matrix deposition.

Front 79

Stages of Endochondrial Ossification: Zones in Plate

Back 79

-Resting (reserve) zone
-Proliferative zone
-Hypertrophic zone
-Calcified cartilage zone (also programmed cell death)
-Ossification/resorption zone

Front 80

Blood is a reservoir for _______ of ______ _______.

Back 80

-Homeostasis
-Blood Calcium

Front 81

What controls blood calcium?

Back 81

-Controlled by the passive transfer of calcium ions from hydroxyapatite crystals to interstitial fluid surrounding osteocytes, and into blood, and the active action of parathyroid hormone and calcitonin.

Front 82

Parathyroid Hormone (def)

Back 82

-Raises blood calcium by activating osteoclasts (and osteocytes) to resorb bone
-Reduces excretions of calcium by the kidney and promotes absorption of calcium by the small intestine

Front 83

Calcitonin (def)

Back 83

-Lowers blood calcium by inhibiting osteoclast activity, thereby inhibiting matrix resorption

Front 84

3 Requirements that Bone needs for proper growth and maintenance

Back 84

-Dietary calcium, which must be absorbed from the gut
-Vitamin D (promotes absorption) (deficiency=rickets)
-Vitamin C for collagen synthesis

Front 85

Similarities between Bone and Cartilage: Cells (origin and location in tissue)

Back 85

-Origin: Both derive from embyronic mesenchymal cells (osteoclasts are derived from bone marrow)
-Location in Tissue: Both reside in lacunae within the matrix

Front 86

Similarities between Bone and Cartilage: Matrix

Back 86

-Both contain collagen fibers embedded in the ground substance

Front 87

Similarities between Bone and Cartilage: Surrounding Connective Tissue

Back 87

-Both are covered by a dense irregular connective tissue (Type I collagen) that forms a "membrane", the PERICHONDRIUM (cartilage) and PERIOSTEUM (bone)
-Articular cartilage does not have a perichondrium

Front 88

Similarities between Bone and Cartilage: Function

Back 88

-Both are primarily supportive

Front 89

Cartilage vs Bone: Flexibility

Back 89

-C: Flexible, pliable
-B: Rigid

Front 90

Cartilage vs Bone: Staining

Back 90

-C: Basophilic when stained with H&E
-B: Acidophilic with H&E (decalcified)

Front 91

Cartilage vs Bone: Connectivity

Back 91

-C: Cells not interconnected
-B: Cells interconnected

Front 92

Cartilage vs Bone: Cell size and shape

Back 92

-C: Larger cells ovoid or spherical shaped
-B: Lenticular cells with many processes

Front 93

Cartilage vs Bone: Cell arrangement

Back 93

-C: Cells reside in lacunae that are often arranged in isogenous nests, particularly in growing cartilage
-B: Cells reside in lacunae that are arranged in lamellae. Cells tend to be evenly be placed

Front 94

Cartilage vs Bone: Immediate Precursors

Back 94

-C: Chondrogenic Cells
-B: Osteogenic cells (Osteoprogenitor)

Front 95

Cartilage vs Bone: Cellularity

Back 95

-C: Many cells (fibrocartilage has relatively few cells)
-B: Few cells

Front 96

Cartilage vs Bone: Intercellular canaliculi

Back 96

-C: No canaliculi
-B: Canaliculi

Front 97

Cartilage vs. Bone: Nutrition of cells

Back 97

-C: Via diffusion through the matrix
-B: Via diffusion through the canaliculi

Front 98

Cartilage vs Bone: Vascularity

Back 98

-C: No blood vessels within the tissue
-B: Haversian and Volkmann's canals carry blood vessels throughout bone

Front 99

Cartilage vs Bone: Collagen

Back 99

-C: Type II fibers less densely packed than bone (about 60% of organic matter)
-B: Type I fibers, densely packed (95% of bone organic matter) and specifically oriented within the lamellae. Embryonic and newly formed bone is less well organized

Front 100

Cartilage: Ground substance

Back 100

-C: Primarily sulfated proteoglycans
-Chondroitin-4-sulfate
-Chondroitin 6-sulfate,
-Keratin sulfate associated with hyaluroinc acid
-Glycoprotein chondronectin that promotes adherence of chondrocytes to matrix

Front 101

Bone: Ground Substance

Back 101

Sulfated glycosaminoglycans
~Chondroitin 4-sulfate
~Chondroitin 6-sulfate
~Keratin sulfate associated with hyaluronic acid
-Specific glycoproteins bone sialoprotein an osteoclacin thought to promote calcification

Front 102

Cartilage vs Bone: Calcification

Back 102

-C: Not normally present
-B: About 62% of the dried bone is inorganic=hydorxyapatite crystals

Front 103

Cartilage vs Bone: Growth

Back 103

-C: Interstitial division of chondrocytes within the matrix
-B: Remodeling (resorption by osteoclasts and deposition of new boney by osteoblasts)