Skeletal system

Flat bones

• protect internal organs

• act as suitable sites for muscular attachment

• e.g. sternum, ribs, cranium and pelvis

Long bones

• act as levers of movement

• act as sites for blood cell production

• e.g. femur, humerus, radius, tibia and phalanges

irregular bones

Protect other vitals

E.g. the vertebrae which protect the spinal cord

short bones

• bears weight well

• e.g. carpals and tarsals

sesamoid bones

• ease joint movement

• resist compression

• embedded within muscles and ligaments

• e.g. patella

Synovial joint

the most common type of joint in the body. These joints vary in structure

Hinge joint

• a cylindrical bone articulates with a trough-shaped bone held tightly by ligaments

• motion is restricted to one plane

• e.g. elbow, knee and ankle joints

Pivot joint

• a rounded bone articulates with a ring shaped bone which restrict motion to one plant

• e.g. the radio-ulnar joint

Ball and socket joint

• a ball shaped head articulates with a cup-shaped socket to give a large range of motion in all three planes

• e.g. hip and shoulder joints

Condyloid joint

• similar to ball and socket joint with flatter bone surface to allow motion in two planes

• e.g. the wrist joint

Gliding joint

• where flat or slightly curved bone surfaces slide over one another, allowing for limited movements such as gliding and some rotations

• e.g. the wrist, ankle