Bones and Cartilages of the Human Body

Figure 6.1

Microscopic Structure of Bone: Compact Bone

Figure 6.5a, b

Classification of Bones: By Shape

•Long bones – longer than they

are wide (e.g., humerus)

Figure 6.2a

Classification of Bones: By Shape

•Short bones–Cube-shaped

bones of the wrist and ankle

–Bones that form within tendons (e.g., patella)

Figure 6.2b

Classification of Bones: By Shape

•Flat bones – thin, flattened,

and a bit curved (e.g., sternum, and

most skull bones)

Figure 6.2c

Classification of Bones: By Shape

•Irregular bones – bones with

complicated shapes (e.g., vertebrae and

hip bones)

Figure 6.2d

Chemical Composition of Bone: Organic

•Osteoblasts – bone-forming cells

•Osteocytes – mature bone cells

•Osteoclasts – large cells that resorb or break down bone matrix

Long Bone Growth and Remodeling

•Growth in length – cartilage continually

grows and is replaced by bone as

shown

•Remodeling – bone is resorbed and

added by appositional growth

as shown

Figure 6.10

Fibrous Structural Joints•The bones are jointed by fibrous tissues

•There is no joint cavity

•Most are immovable

Figure 8.1a

Cartilaginous Joints

•Articulating bones are united by cartilage

•Lack a joint cavity

Figure 8.2a

Cartilaginous Joints

Figure 8.2b

Cartilaginous Joints

Figure 8.2c

Synovial Joints: General Structure

•Synovial joints all have the following:

–Articular cartilage–Joint (synovial)

cavity–Articular capsule–Synovial fluid–Reinforcing

ligaments

Figure 8.3a

Synovial Joints: Range of Motion

•Nonaxial – slipping movements only

•Uniaxial – movement in one plane

•Biaxial – movement in two planes

•Multiaxial – movement in or around all three planes

Types of Synovial Joints•Plane joints

–Articular surfaces are essentially flat

–Allow only slipping or gliding

movements–Only examples of

nonaxial joints

Figure 8.7a

Types of Synovial Joints

•Hinge joints–Motion is along a single

plane–Uniaxial joints permit

flexion and extension only

–Examples: elbow and interphalangeal joints

Figure 8.7b

Pivot Joints

•Only uniaxial movement allowed

•Examples: joint between the axis and the dens, and

the proximal radioulnar joint

Figure 8.7c

Condyloid, or Ellipsoidal, Joints

•Biaxial joints permit all angular motions

•Examples: radiocarpal (wrist) joints, and

metacarpophalangeal (knuckle) joints

Figure 8.7d

Saddle Joints•Similar to condyloid

joints but with greater movement

•Example: carpometacarpal joint

of the thumb

Figure 8.7e

Ball-and-Socket Joints

•Multiaxial joints permit the most

freely moving synovial joints

•Examples: shoulder and hip joints

Figure 8.7f