Cartilage, Bones, and Joints

Question 1

Chondrocytes

Answer 1

component of cartilage. Live in lacunae. Secrete matrix.

Question 2

What is in cartilage?

Answer 2

there are no vessels or nerves, so nutrients must diffuse in. Cannot be a source of pain

Question 3

Types of Cartilage Growth

Answer 3

1. appositional

2. interstitial

Question 4

Appositional Growth

Answer 4

expansion from periphery. Continues throughout life. From perichondrium. Source of stem cells

Question 5

Perichondrium

Answer 5

outer layer of cartilage responsible for appositional growth.

Question 6

Does articular cartilage have a perichondrium?

Answer 6

no, so it cannot continue growing

Question 7

Interstitial Growth

Answer 7

expansion from within. Matrix and cell numbers increase. result in isogenous group. Most important in young animals

Question 8

Isogenous Group

Answer 8

multiple cells in a cluster, characteristic of interstitial growth

Question 9

Types of Cartilage

Answer 9

1. Hyaline
2. Elastic
3. Fibrocartilage

Question 10

Hyaline Cartilage

Answer 10

glassy. Found in fetal skeleton and articular surfaces of bone

Question 11

Locations of Hyaline Cartilage

Answer 11

respiratory tree- nose, larynx, trachea

Question 12

Elastic Cartilage

Answer 12

has elastic fibers between chondrocytes.

Question 13

How to visualize elastic fibers in elastic cartilage?

Answer 13

cannot see on routine stain, need elastin stain

Question 14

Locations of Elastic cartilage

Answer 14

pinnae, external ear canal

Question 15

Fibrocartilage

Answer 15

cartilage mixed with dense collagen. Chondrocytes are in rows

Question 16

Locations of Fibrocartilage

Answer 16

menisci, intervertebral discs, tendon and ligament attachments to bone

Question 17

Components of bone

Answer 17

cells and matrix

Question 18

Types of bone cells

Answer 18

osteoblasts, osteocytes, and osteoclasts

Question 19

Osteoblasts

Answer 19

produce bone. Polygonal cells in rows along bone surface. Secrete and mineralize osteoid

Question 20

Osteoid

Answer 20

unmineralized bone

Question 21

Osteocytes

Answer 21

embedded osteoblasts. Live in lacunae. Communicate with each other

Question 22

Osteoclasts

Answer 22

remove bone. Multinucleated giant cells of bone marrow origin. Bone removal occurs along brush or ruffled border.

Question 23

Howship’s Lacunae

Answer 23

depression in bone formed by osteoclast

Question 24

Types of Matrix

Answer 24

mineral and collagen

Question 25

Mineral Matrix

Answer 25

the majority of the bone is mineral. Mineral gives bone its rigidity

Question 26

Hydroxyapatite Crystal

Answer 26

calcium and phosphorus in a 5:3 ratio

Question 27

Collagen Matrix

Answer 27

polarized light required to see collagen. Gives bone its tensile strength.

Question 28

Microscopic Organization of Bone Collagen

Answer 28

woven bone and lamellar bone

Question 29

Woven Bone

Answer 29

immature bone. Formed during growth and repair. haphazardly arranged collagen fibers

Question 30

Lamellar Bone

Answer 30

mature bone. Parallel collagen fibers.

Question 31

Osteon

Answer 31

cylinders of concentric lamellae. Haversian canals at center of osteon. Blood vessels and nerves within canal. Stronger than woven bone

Question 32

Configuration of Bone

Answer 32

compact bone and cancellous bone

Question 33

Compact Bone

Answer 33

solid bone with minimal marrow. Can be woven or lamellar. Cortex of adult bone is compact lamellar

Question 34

Cancellous Bone

Answer 34

Trabeculae arranged in a 3 dimensional lattice. More bone marrow spaces than compact bone. Can be woven or lamellar. Present inside bone medullary cavity

Question 35

Epiphysis

Answer 35

end of bone, covered with articular cartilage

Question 36

Physis

Answer 36

clear line. Growth plate made of cartilage only present in growing animals

Question 37

Metaphysis

Answer 37

cone-shaped transition between diaphysis and epiphysis

Question 38

Diaphysis

Answer 38

cylindrical shaft of bone that contains nutrient foramen

Question 39

Nutrient Foramen

Answer 39

opening for blood vessel to come in in bone

Question 40

Marrow

Answer 40

contains hematopoietic cells. Becomes increasingly fatty with age

Question 41

Periosteum

Answer 41

fibrous outer bony envelope. contains osteoprogenitor cells. Involved in repair and remodeling

Question 42

Where does osteosarcoma occur

Answer 42

in metaphysis

Question 43

Endosteum

Answer 43

inner bony envelope

Question 44

Types of Ossification

Answer 44

1. endochondral ossification | 2. intramembranous ossification

Question 45

Endochondral Ossification

Answer 45

replacement of hyaline cartilage template by bone. Bone formation within cartilage

Question 46

Layers of Physis inEndochondral Ossification

Answer 46

1. Resting chondrocytes 2. Proliferating chondrocytes that look like stack of coins 3. Hypertrophied chondrocytes. Cells are swollen. Weakest zone

Question 47

Osteoid

Answer 47

mineralized to form woven bone which covers remaining cartilage cores

Question 48

Salter-Harris Fractures

Answer 48

Fractures in physis. Affect bone growth in young animals

Question 49

Intramembranous Ossification

Answer 49

replacement of mesenchymal template by bone. Bone forms from condensed mesenchymal cells. Cartilage is not involved

Question 50

What determines bone density?

Answer 50

weight bearing

Question 51

Types of Joints

Answer 51

1. fibrous 2. cartilaginous 3. synovial

Question 52

Fibrous Joints

Answer 52

bones connected by dense collagen

Question 53

Cartilaginous Joints

Answer 53

bones connected by fibrocartilage

Question 54

Synovial Joints

Answer 54

ends of bones covered by hyaline cartilage. Bones connected by ligaments (attached to bone by fibrocartilage) and fibrous joint capsule.

Question 55

Synovial Membrane

Answer 55

Lines the inside of joint and inside of tendon sheaths.

Question 56

Synoviocytes

Answer 56

produce synovial fluid

Question 57

Synovial Fluid

Answer 57

lubricates joint (very viscous)