Anatomy of the Skeletal System

Anatomy of the Skeletal System

• Overview

  • The skeletal system provides structure, support, and protection to the body.
  • Composed of bones, cartilage, ligaments, and joints.

• Types of Bones

  1. Long Bones
     • Examples: Femur, humerus.
     • Function: Support weight and facilitate movement.
  2. Short Bones
     • Examples: Carpals, tarsals.
     • Function: Provide stability and support with little movement.
  3. Flat Bones
     • Examples: Sternum, ribs, skull.
     • Function: Protect internal organs and provide surface area for muscle attachment.
  4. Irregular Bones
     • Examples: Vertebrae, pelvis.
     • Function: Support and protect organs while allowing for flexibility.

• Bone Structure

  • Diaphysis: The shaft of long bones, primarily composed of compact bone.
  • Epiphysis: The end part of long bones, containing spongy bone and red marrow.
  • Metaphysis: The region between diaphysis and epiphysis, where growth occurs in children.
  • Articular Cartilage: Covers ends of bones at joints to reduce friction.
  • Periosteum: A dense layer of vascular connective tissue enveloping the bones except at surfaces of joints.

• Bone Composition

  • Organic Components: Collagen fibers and cells (osteoblasts, osteocytes, osteoclasts).
  • Inorganic Components: Minerals (mainly calcium phosphate) that provide hardness.

• Joint Types

  1. Fibrous Joints: Immovable joints (e.g., skull sutures).
  2. Cartilaginous Joints: Slightly movable (e.g., intervertebral discs).
  3. Synovial Joints: Freely movable and most common type (e.g., knee, hip).

• Skeletal Categories

  • Axial Skeleton: Consists of 80 bones including the skull, vertebral column, and rib cage.
  • Appendicular Skeleton: Comprises 126 bones including the limbs and girdles.

• Functions of the Skeletal System

  • Provides shape and support.
  • Protects vital organs (e.g., brain, heart).
  • Facilitates movement by serving as levers for muscles.
  • Stores minerals (e.g., calcium, phosphorus).
  • Produces blood cells in bone marrow (hematopoiesis).

• Bone Remodeling

  • The ongoing process of bone resorption and formation.
  • Influenced by mechanical stress, hormonal changes, and nutritional factors.

Overview of the Skeletal System

• Provides structure, support, and protection for the body.
• Composed of bones, cartilage, ligaments, and joints.

Types of Bones

• Long Bones

  • Examples: Femur, humerus.
  • Function: Support body weight and facilitate movement.

• Short Bones

  • Examples: Carpals, tarsals.
  • Function: Provide stability and support with minimal movement.

• Flat Bones

  • Examples: Sternum, ribs, skull.
  • Function: Protect internal organs and provide surface area for muscle attachment.

• Irregular Bones

  • Examples: Vertebrae, pelvis.
  • Function: Support and protect organs while allowing flexibility.

Bone Structure

• Diaphysis: Shaft of long bones, primarily made of compact bone.
• Epiphysis: End part of long bones with spongy bone and red marrow.
• Metaphysis: Growth region between diaphysis and epiphysis in children.
• Articular Cartilage: Covers endings of bones at joints to reduce friction.
• Periosteum: Vascular connective tissue surrounding bones, excluding joint surfaces.

Bone Composition

• Organic Components: Include collagen fibers and bone cells (osteoblasts, osteocytes, osteoclasts).
• Inorganic Components: Mainly minerals like calcium phosphate, which confer hardness to bones.

Joint Types

• Fibrous Joints: Immovable (e.g., skull sutures).
• Cartilaginous Joints: Slightly movable (e.g., intervertebral discs).
• Synovial Joints: Freely movable and most common (e.g., knee, hip).

Skeletal Categories

• Axial Skeleton: 80 bones including skull, vertebral column, and rib cage.
• Appendicular Skeleton: 126 bones comprising limbs and girdles.

Functions of the Skeletal System

• Provides shape and structural support.
• Protects vital organs like the brain and heart.
• Facilitates movement as levers for muscles.
• Stores minerals such as calcium and phosphorus.
• Produces blood cells in bone marrow (hematopoiesis).

Bone Remodeling

• Continuous process involving bone resorption and formation.
• Influenced by mechanical stress, hormonal changes, and nutritional factors.