Connective tissue – Bone and Cartilage

Question 1

Origin of cartilage

Answer 1

Mesenchyme during the 5th week of development

Question 2

General features of cartilage

Answer 2

Avascular, poor ability for regeneration

Question 3

Growth types of cartilage

Answer 3

Appositional (from the surface) and interstitial (from the inside)

Question 4

Perichondrium

Answer 4

covers cartilage, made of dense irregular tissue

Question 5

Cell types in cartilage

Answer 5

Chrondroblasts and chondrocytes

Question 6

Chondroblasts

Answer 6

Cells close to the surface, appositional growth, secrete the matrix

Question 7

Chondrocytes

Answer 7

Embedded chondroblasts that occupy the lacunae, produce/maintain the ECM, interstitial growth

Question 8

Isogenous groups

Answer 8

Cell clusters of divided chrondrocytes

Question 9

Main type of collagen found in cartilage

Answer 9

Type II collagen

Question 10

What attaches chondrocytes to the cell matrix?

Answer 10

multi adhesive glycoproteins

Question 11

Territorial matrix

Answer 11

area that surrounds the lacunae that is richer in GAGs

Question 12

Interterritorial matrix

Answer 12

matrix in-between the lacunae, less intensely staining

Question 13

Types of cartilage

Answer 13

Hyaline, elastic, fibrocartilage

Question 14

Hyaline cartilage

Answer 14

well developed perichondrium, dense irregular tissue, ECM has no visible fibers, chondrocytes are often in isogenous groups

Question 15

Elastic cartilage

Answer 15

Well developed perichondrium, ECM has elastic fibers, chondrocytes are in large/distended lacunae

Question 16

Fibrocartilage

Answer 16

Hybrid b/t hyaline and dense irregular connective tissue, does NOT have a perichondrium, has BOTH type I&II collagen

Question 17

Chondrosarcoma

Answer 17

Malignant proliferation of cartilage, wide age range with a slight male predominance

Question 18

Compact bone

Answer 18

Outer ridge shell of bone

Question 19

Spongy bone

Answer 19

spicules/trabeculae on the inner side of the bone

Question 20

Marrow cavity

Answer 20

Reticular, hemopoietic connective tissue or adipose tissue

Question 21

Periosteum

Answer 21

Dense irregular tissue that covers the external layer of bone, will have 2 layers of bone is actively growing (external-fibrous and internal-osteogenic)

Question 22

Osteoprogenitor cells

Answer 22

cells that form from the mesenchyme that will differentiate into osteoblasts

Question 23

Organic bone matrix

Answer 23

Type I collagen, little ground substances, has unique multiadhesive glycoproteins to bind matrix material

Question 24

Inorganic bone matrix

Answer 24

Most calcium phosphate, calcium carbonate, Mg, Na, K

Question 25

Osteoblasts

Answer 25

principle bone-forming cells, only found at the boundary between bone and the adjacent tissue

Question 26

Osteocytes

Answer 26

Osteoblast that are trapped in the matrix, housed in lacunae, form canaliculi to connect the lacunae

Question 27

Osteoclasts

Answer 27

Large-multinucleated cells; reabsorb the bone

Question 28

Clear zone

Answer 28

Actin-rich area that osteoclasts attach to

Question 29

Ruffled border

Answer 29

part of the osteoclast in direct contact with the bone

Question 30

Osteosarcoma

Answer 30

Malignant proliferation of osteoblasts, 20% of primary bone cancers, high metastatic

Question 31

Osteoid osteoma

Answer 31

Small, benign tumor usually in the appendicular skeleton or spine that causes acute night pains

Question 32

Paget's disease

Answer 32

Enlarged, deformed bones that are prone to fracture

Question 33

Primary (woven) bone

Answer 33

Immature type of bone laid down for bone repair

Question 34

Secondary (lamellar) bone

Answer 34

main structural unit is the osteon

Question 35

Haversian canal

Answer 35

Longitudinal canal with the neurovascular bundle

Question 36

Lamellae

Answer 36

Surrounds the canals concentrically

Question 37

Canaliculi

Answer 37

Connect the lacunae

Question 38

Lacunae

Answer 38

Houses the osteocytes between the lamellae

Question 39

Volkmann's canal

Answer 39

Transverse canals with neurovascular bundles

Question 40

Interstitial lamellae

Answer 40

Remnants of the old Haversian system

Question 41

Types of ossification

Answer 41

Intramembranous and Endochondrial

Question 42

Intramembranous ossification

Answer 42

Bone formed directly from connective tissue

Question 43

Primary ossification center

Answer 43

Region of initial intramembranous ossification

Question 44

Endochondrial ossification definition

Answer 44

Replacement of cartilaginous tissue with bony tissue

Question 45

Endochondrial ossification steps

Answer 45

1) hyaline cartilage model forms 2)cartilage grows 3)cuff of bone formed around diaphysis 4)midregion of cartilage calcifies (lack of nutrients) 5)chondrocytes die 6) blood vessels/osteoprogenitors degenerate cartilage 7) osteoblasts secrete bone matrix 8)matrix replaces cartilage

Question 46

Primary ossification center for long bones

Answer 46

Diaphysis

Question 47

Secondary ossification center for long bones

Answer 47

Epiphyses

Question 48

Epiphyseal plate zones

Answer 48

Reserve cartilage, proliferation, hypertrophy, calcification, ossification

Question 49

Epiphyseal plate zones: reserve cartilage

Answer 49

hyaline cartilage with chondrocytes

Question 50

Epiphyseal plate zones: Proliferation

Answer 50

rapid tissue growth, chondrocytes divide to form stacked cells parallel to the long axis of the bone

Question 51

Epiphyseal plate zones: Hypertrophy

Answer 51

Chondrocytes swell in size

Question 52

Epiphyseal plate zones: Calcification

Answer 52

Chondrocytes lost via apoptosis, matrix is calcified

Question 53

Epiphyseal plate zones: ossification

Answer 53

Osteoblasts synthesize bone tissue over the calcified cartilage