Chp 6 Bone Tissue

Front 1

Diaphysis

Back 1

The bone's shaft or body, the long cylindrical main portion of the bone.

Front 2

Epiphysis

Back 2

The proximal and distal ends of the bone.

Front 3

Metaphysis

Back 3

The regions between the diaphysis and the epiphyses.

Front 4

Epiphyseal Plate

Back 4

The metaphysis in a growing bone. This is where the cells grow and add length.

Front 5

Articular Cartilage

Back 5

Thin layer of hyaline cartilage covering the part of the epiphysis where the bone forms an articulation (joint) with another bone. Reduces friction and absorbs shock.

Front 6

Periosteum

Back 6

Surrounds the external bone surface wherever it isn't covered by articular cartilage. Allows bone to grow in thickness, protects bone, assists in fracture repair and serves as an attachment point for ligaments and tendons.

Front 7

Medullary Cavity

Back 7

A hollow, cylindrical space within the diaphysis that contains fatty yellow bone marrow in adults.

Front 8

Endosteum

Back 8

A thin membrane that lines the internal bone surface facing the medullary cavity. Contains a single layer of cells and a small amt of CT.

Front 9

Osteogenic Cells

Back 9

Unspecialized stem cells derived from mesenchyme; the only bone cells to undergo cell division.

Front 10

Osteoblast Cells

Back 10

Bone-building cells

Front 11

Osteocytes

Back 11

Mature bone cells in bone tissue that maintain its daily metabolism.

Front 12

Osteoclasts

Back 12

Breaks down bone

Front 13

Calcification

Back 13

As mineral salts are deposited in the framework of collagen fibers, they crystallize and the tissue hardens.

Front 14

Compact Bone

Back 14

Contains few spaces and is the strongest form of bone tissue. Provides protection and support and resists the stresses produced by weight and movement.

Front 15

Haversian System

Back 15

AKA Osteon
The components of compact bone tissue are arranged into repeating structural units.

Front 16

Perforating (Volkmann's) Canal

Back 16

Canals in which blood vessels, lymphatic vessels and nerves travel through.

Front 17

Central (Haversian) Canal

Back 17

A canal that runs longitudinally through the bone.

Front 18

Lamellae

Back 18

Rings of calcified extracellular matrix much like the rings of a tree trunk.

Front 19

Canaliculi

Back 19

Small channels radiating in all directions from the lacunae which are filled with extracellular fluid.

Front 20

Lacuna

Back 20

Small spaces which contain osteocytes.

Front 21

Spongy Bone

Back 21

Does not contain osteons. Consists of lamellae arranged in an irregular pattern with macroscopic spaces to help make the bone lighter.

Front 22

Trabecula

Back 22

An irregular lattice of thin columns found in spongy bone.

Front 23

Ossification

Back 23

The process by which bone is formed.

Front 24

Intramembranous Ossification

Back 24

When bone forms directly within mesenchyme arranged in sheetlike layers that resemble membranes.

Front 25

Endochondrial Ossification

Back 25

When bone forms within hyaline cartilage that develops from mesenchyme.

Front 26

Interstitial Growth

Back 26

Growth from within the cartilage and results in an increase of length.

Front 27

Appositional Growth

Back 27

Growth at the outer surface and results in an increase in thickness.

Front 28

Ossification Center

Back 28

A site where specific chemical messages cause the mesenchymal cells to cluster together and differentiate, first into osteogenic cells and then into osteoblasts.

Front 29

Primary Ossification Center

Back 29

A region where the bone tissue will replace most of the cartilage. This occurs in the middle of the bone.

Front 30

Secondary Ossification Center

Back 30

When branches of the epiphyseal artery enter the epiphyses, these centers develop. Bone formation is similar to that in the Primary Ossification Center.

Front 31

Fracture

Back 31

Any break in a bone

Front 32

Hematoma

Back 32

When blood vessels crossing the fracture line are broken and blood leaks from the vessels to create a mass of blood around the fracture. Typically takes several weeks.

Front 33

Callus

Back 33

A mass of repair tissue consisting of collagen fibers and cartilage that bridges the broken ends of the bone. Typically takes 3 wks.

Front 34

Remodeling

Back 34

The final phase of fracture repair. Dead portions of the original fragments of broken bone are gradually absorbed by osteoclasts. Typically, a thickened area on the surface of the bone remains.

Front 35

Reduction

Back 35

When the fractured ends are brought into alignment (typically called "setting a fracture.").

Front 36

Parathyroid Hormone (PTH)

Back 36

This hormone regulates Ca2+ exchange and causes the amt in the body to increase. Operates via Negative Feedback.

Front 37

Calcitonin (CT)

Back 37

This hormone regulates Ca2+ exchange and causes the amt in the body to decrease. Promotes bone formation.