Skeletal System Overview

Skeletal System Overview

• Divided into two subgroups: axial skeleton and appendicular skeleton.
• Axial skeleton includes skull (cranium), vertebral column, ribs, and sternum.
• Appendicular skeleton consists of bones in the upper and lower limbs.

Cartilage

• Functions include supporting soft tissues, providing smooth surfaces for joints, and enabling growth of long bones.
• Types of cartilage:
  • Hyaline cartilage: most common, found in articular surfaces of bones.
  • Elastic cartilage: found in structures like the external ear.
  • Fibrocartilage: found in intervertebral discs.
• Cartilage is avascular, nourished by diffusion, and contains no blood vessels, lymphatics, or nerves.

Bone

• Functions include structural support, protection of vital organs, reservoir for calcium and phosphorus, levers for muscle movement, and housing for blood-producing cells.
• Types of bone:
  • Compact bone: dense outer shell of all bones, surrounding spongy bone.
  • Spongy (trabecular or cancellous) bone: contains spicules of bone with cavities for blood-forming cells (marrow).

Classification of Bones by Shape

• Long bones: tubular structure (e.g., humerus, femur).
• Short bones: cuboidal shape (e.g., wrist and ankle bones).
• Flat bones: two compact bone plates separated by spongy bone (e.g., skull).
• Irregular bones: varied shapes (e.g., bones of the face).
• Sesamoid bones: round or oval bones developing in tendons (e.g., patella).

Additional Notes

• Bones are vascular and innervated, facilitating growth and repair.

Explore the skeletal system through this quiz, which covers the key components of both the axial and appendicular skeletons. Learn about the roles and functions of bones and cartilage in supporting the body and facilitating movement. Test your knowledge on the anatomy and physiology of the skeletal system.