Skeletal System

Functions of the Skeletal System• THINK! – What are the four levels of

organization?• Cells, Tissues, Organs, Organ Systems

• Provides shape & support (206 bones)

• Allows for body movement with its 26 vertebrae in the backbone

• Protects the internal organs

• Produces blood cells

• Stores certain materials like calcium and phosphorus

Activity: Turn to your partner and Label the Human Skeleton

Joints of the Skeleton

• Brain Pop: How Joints Work!

• Places in the body where two bones meet

• Immovable Joints

• allows no movement

• bones of skull & ribs to sternum

Joints of Skeleton

• Ball & Socket Joint

• allows the greatest range of motion

• Shoulder & Hip

Joints of Skeleton

• Pivot Joint

• Allows one bone to rotate around another

• Neck, arm (radius)

Joints of Skeleton

• Hinge Joint

• Allows forward & backward motion

• Knee, Elbow, Phalanges,

Mandible

Joints of Skeleton

• Gliding Joint

• allows one bone to slide over another

• allows bend and flex as well as limited side-to-side motion

• Wrist, ankles, vertebrae

• THINK! – What connective tissue connects bone to bone?

• Ligaments

Bone Growth• THINK! – Take a look at

the picture to the right. How do you think a child’s bones grow over time?• Cartilage is replaced

slowly by bone as solid tissue grows outward. Over time, the bone reshapes to include blood vessels, nerves, and marrow.

• Osteoblasts are bone forming cells

• Osteoclasts are cells which break down bone releasing calcium into the bloodstream

Structure of BoneBrain Pop: Bone Structure

Structure of Bone• Periosteum – membrane that covers all of the

bone except ends

• Compact bone – found underneath membrane• Hard and dense but not solid• Canals carry blood vessels and nerves from bone’s

surface to living bone cells.

• Spongy bone - inside compact bone and at ends

• Marrow (contained in bone spaces)• Red - produces body’s blood cells• Yellow – stores fat that serves as an energy reserve