NPH 1001: Skeletal System Overview

Introduction

• Presenter: Fiona
• Course Reference: Chapter 7 of the course textbook
• Focus: Summary of skeletal system (excludes joints/articulation)

Functions of the Skeletal System

• Support structure for the body
• Protects major organs (e.g., lungs and heart in thoracic cavity, brain by the skull)
• Stores mineral salts
• Works with muscles for movement
• Hematopoiesis: Blood cell formation in bone marrow

Important Components

• Cartilage: Prevents friction at joints, acts as a cushion
• Tissues: Ligaments (bone to bone) and tendons (muscle to bone)

Bone Formation and Growth

• Ossification: Process of bone formation
  • Osteoblasts: Cells responsible for bone formation
  • Epiphyseal line: Site of bone elongation
  • Maturation: Adult height by age 15-16, bone maturity by age 21

Types of Bone Cells

• Osteoblasts: Bone-forming cells
• Osteocytes: Mature bone cells
• Osteoclasts: Remodel and repair bones

Types of Ossification

• Intramembranous: Bone formation within membranes (e.g., cranial bones)
• Endochondral: Bone formation within cartilage (most bones)

Bone Tissue Types

• Compact Bone: Densely packed cells, provides strength
• Spongy Bone: Loosely packed cells, houses bone marrow

Bone Classification by Shape

• Long Bones: Length exceeds width (e.g., femur)
• Short Bones: Lack a long axis, irregular (e.g., carpal bones)
• Flat Bones: Extensive muscle attachment or protection (e.g., skull, ribs)
• Irregular Bones: Complex shapes (e.g., vertebrae)
• Sesamoid Bones: Embedded within tendons, near joints

Vertebral Column

• Cervical Region: 7 vertebrae
• Thoracic Region: 12 vertebrae, attached to ribs
• Lumbar Region: 5 vertebrae
• Sacrum: 5 fused vertebrae
• Coccyx: 4 fused vertebrae

Skeletal System Division

• Axial Skeleton: Skull, ribs, sternum, vertebrae
• Appendicular Skeleton: Limbs and extremities

Skull and Facial Bones

• Composed of flat bones
• Important bones: Zygomatic, mandible, temporal, occipital

Thoracic Cage

• 12 pairs of ribs
  • True Ribs: First 7 pairs, directly attached to sternum
  • False Ribs: Next 5 pairs, last 2 are floating ribs

Extremities

• Upper Extremities: Humerus, radius, ulna, carpals, metacarpals, phalanges
• Lower Extremities: Femur, patella, tibia, fibula, tarsals, metatarsals

Changes with Age

• Shrinkage in height due to thinning vertebral discs

Summary

• Comprehensive review of skeletal system functions, bone types, and structure
• Importance of identifying major bones and regions