Chapter 6: Osseous Tissue and Bone Structure

The Skeletal System Skeletal system includes: –bones of the skeleton –cartilages, ligaments, and connective tissues

What are the Functions of the Skeletal System? 1.Stabilize and Support the body 2.Storage of minerals (calcium) 3.Storage of lipids (yellow marrow) 4.Blood cell production (red marrow) 5.Protect internal tissues and organs 6.Movement through “Lever” Action when contracted (Leverage=force of motion)

How are Bones Classified? Bone are identified by: –shape –bone markings –Internal cells and tissues

What are the 6 major Bone Shapes? 1.Long bones 2.Flat bones 3.Sutural bones 4.Irregular bones 5.Short bones 6.Sesamoid bones

Long Bones Are long and thin Are found in arms, legs, hands, feet, fingers, and toes

Flat Bones Are thin with parallel surfaces Are found in the skull, sternum, ribs, and scapula

Sutural Bones Are small, irregular bones Are found between the flat bones of the skull

Irregular Bones Have complex shapes Examples: –spinal vertebrae –pelvic bones

Short Bones Are small and thick Examples: –ankle –wrist bones

Sesamoid Bones Are small and flat Develop inside tendons near joints of knees, hands, and feet

What are Bone Markings The surface features of bones include depressions or grooves where tendons, ligaments and neighboring bones attach, and tunnels where blood and nerves enter the bone. Depressions or grooves: –along bone surface Projections: –where tendons and ligaments attach –at articulations with other bones Tunnels: –where blood and nerves enter bone

Bone Markings Table 6–1 (1 of 2)

Bone Markings Table 6–1 (2 of 2)

Long Bones Diaphysis: –the shaft Epiphysis: –wide part at each end –articulation with other bones Metaphysis: –where diaphysis and epiphysis meet

Diaphysis (shaft) A heavy wall of compact bone, or dense bone A central space called marrow cavity Epiphysis (ends) Mostly spongy (cancellous) bone Covered with compact bone (cortex) Metaphysis (connection between diaphysis and epiphysis) The metaphysis is the flared end of the diaphysis where the shaft merges with the epiphysis. Periosteum surrounds the diaphysis; endosteum lines the medullary cavity. At the epiphyseal line, cartilage separates the epiphysis from the diaphysis.

Flat Bones The parietal bone of the skull Resembles a sandwich of spongy bone Between 2 layers of compact bone Figure 6–2b