Ch. 5 - Bone

Question 1

Function of bone

Answer 1

Support (Structural framework)
Protection (i.e. Skull, vertebrae, rib-cage)
Movement (Attachment for muscles)
Mineral homeostasis (Ca++ balance)
Blood cell production (RBC and WBC, red bone marrow)
Fat storage (Yellow bone marrow)

Question 2

Hyaline cartilage (Functions)

Answer 2

Development and growth of bone (bone replaces cartilage model)
Cushioning of joints (Articular cartilage, Costal cartilage)
Protection in respiratory system

Question 3

Elastic cartilage

Answer 3

Elastic fibers that stretch and recoil
Repeated bending (i.e. Ear Epiglottis)

Question 4

Fibrocartilage

Answer 4

Collagen fibers resist stretching and compression

Location: Intervertebral discs, Meniscus in knee, Pubic symphysis

Question 5

Long Bone

Answer 5

Epiphysis (Articulating cartilage, spongy bone)
Metaphysis (Epiphyseal line)
Diaphysis (Medullary cavity, Endosteum, Compact bone, Periosteum)

Question 6

Flat Bone

Answer 6

Consists of spongy bone sandwiched between compact bone

Question 7

Bone matrix

Answer 7

25% water
25% collagen (adding flexibility)
50% salts (deposited on collagen fibers making bones hard

Question 8

Bone cells

Answer 8

Osteogenic cells
Osteoblasts
Osteocytes
Osteoclasts

Question 9

Osteogenic cells

Answer 9

Stem cells (periosteum, endosteum)

Question 10

Osteoblasts

Answer 10

Produce new bone tissue

Question 11

Osteocytes

Answer 11

Maintain bone tissue

Question 12

Osteoclasts

Answer 12

Break down bone matrix

Question 13

Periosteum

Answer 13

Membrane around the bone
Outer layer: Connective tissue
Inner layer: Osteogenic cells and osteoblasts

Question 14

Osteon

Answer 14

Basic bone unit with concentric lamellae, osteocytes, and a central canal with blood and lymphatic vessels

Question 15

Osteocyte

Answer 15

Basic bone cell, in lacuna, with canaliculi to allow nutrients to pass from the central canal to the outer edges of the osteon

Question 16

Spongy Bone

Answer 16

No central canal, but still concentric lamellae. Made up of trabeculae, and has osteoblasts on the outer edge

Question 17

Blood Supply

Answer 17

Blood vessels on either side of the epiphyseal line. In the diaphysis, nutrient blood vessels enter through nutrient foramen. In the epiphysis, blood vessels enter through the sides

Question 18

Bone Growth

Answer 18

Intramembranous ossification

Endochondral ossification

Question 19

Intramembranous ossification

Answer 19

Flat bones form between two membranes (From the outside in). Mesenchyme becomes osteogenic cells which become osteoblasts… Osteoblasts stay on the outside producing bone matrix inside

Question 20

Endochondral ossification

Answer 20

A cartilage model of the bone forms (Bone tissue replaces the cartilage)

Question 21

Center of ossification

Intramembranous ossification

Answer 21

Mesenchyme cells cluster and become osteogenic cells
Osteogenic cells develop into Osteoblasts
Osteoblasts produce bone matrix

Question 22

Calcification

Intramembranous ossification

Answer 22

Osteoblasts become osteocytes that lie in lacuna
Matrix hardens (calcification)

Question 23

Formation of Spongy bone

Intramembranous ossification

Answer 23

Trabecula grow to form spongy bone

Question 24

Formation of compact bone

Intramembranous ossification

Answer 24

The periosteum develops on the surface

Osteoblasts put down compact bone tissue

Question 25

Endochondral ossification

Answer 25

1. • Mesenchyme cells become chonroblasts
   • Hyalin cart. surrounded by perichondrium
   • Growth of model bone

2.

• Primary ossification center forms
• Chondrocytes begin calcification
• Bone collar forms (periosteum)
• Growth into and up diaphysis

3. Blood vessels grow into model
   Spongy bone continues to form
   The medullary cavity forms (osteoclasts)

4.
Periosteum forms compact bone
Secondary centers of ossification in epiphysis

5.
Bone spreads through the epiphysis and the diaphysis

6.
Cartilage remains in the bone (Epiphyseal plate, Articulating surfaces)

Question 26

Bone Growth (Length)

Answer 26

From normal cartilage on the articulating surface, to proliferation area, to hypertrophy area (mature chondrocytes), to the calcification area (bone formation), to the bone