The Skeletal System

By Tess Grimaldi

Function

• Provides support, movement, and protection

• Blood cell production• Calcium storage• Endocrine regulation

Structure

• 206 bones (300-350 at first; fuse together, most have 206 by age 9)

• Includes bones, tendons, ligaments, and cartilage

• Separated into two distinctive parts:– Axial skeleton (vertebral

column, rib cage, skull)– Appendicular skeleton

(pectoral girdles, upper limbs, pelvic girdle, lower limbs)

Structure ctd.Periosteum: softer outer covering; provides blood flow to bone; helps bones heal, grow, and fight infectionCompact/Cortical bone: hard bone layer. Provides protection.Spongy/Cancellous bone: less dense layer; heals faster than

compact bone wouldBone marrow: innermost layer. Where

blood cells are made

Diseases

• Osteoperosis: bones lose calcium, thin out, can disappear

• Arthritis: inflammatory, damages joints & surrounding structures

• Scoliosis: curved spine (“C” or “S” shape)

• Leukemia/bone cancer: white blood cells multiply uncontrollably; primarily related to blood, but begins in bone marrow.

• Breaks, fractures, strains, etc.

The study of the skeletal system is referred to as

orthopedics.