Skeletal System 2 (Skeletal System Organisation)

• Axial Skeleton


  • Forms the longitudinal axis of the body
  • Has 80 bones including vertebrae, skull, face, ribs, sternum
  • Functions: Support and protect organs, attaches to muscles
• Appendicular Skeleton


  • Attached to the axial skeleton
  • Functions: Movement and support
• Bones of the Axial Skeleton


  • Skull
  • Face
  • Auditory ossicles
  • Ribs
  • Vertebral column
  • Thoracic cage
• Bones of the Appendicular Skeleton

  • Associated bones
• Components of the Axial Skeleton

  • Skull and associated bones
• The spine or vertebral column protects the spinal cord, supports the head and body, and has 4 spinal curves: Cervical, Thoracic, Lumbar, Sacral
• Components of the Vertebral Column

  • 24 vertebrae, sacrum, coccyx
• Number of Vertebrae in the Vertebral Column

  • 7 cervical vertebrae
  • 12 thoracic vertebrae
  • 5 lumbar vertebrae
• The intervertebral disks are pads of fibrocartilage that separate the vertebral bodies and absorb shocks
• The vertebral canal provides a location for the spinal cord and encloses it
• The vertebral foraminae are gaps between adjacent vertebrae for nerve connections
• The skeleton of the chest is called the Thoracic Cage
• Intervertebral disks


  • Are pads of fibrocartilage
  • Separate the vertebral bodies
  • Absorb shocks
• Vertebral canal


  • Provides location for spinal cord
  • Encloses the spinal cord
• Vertebral foraminae


  • Gaps between adjacent vertebrae
  • Nerve connections
• The Thoracic Cage supports the thoracic cavity
• Components of the Thoracic Cage

  • Thoracic vertebrae
  • Ribs and costal cartilages
  • Sternum (breastbone)
• The Thoracic Cage protects organs
• The ribs and sternum absorb shocks, are flexible, mobile, and support breathing
• The width and depth of the thoracic cage alters volume
• Sternum

  • Flat bone
  • Midline of wall
  • Xiphoid process attaches to diaphragm and rectus abdominis
• The Appendicular Skeleton allows us to move and manipulate objects
• Components of the Pectoral Girdle

  • 2 clavicles
  • 2 scapulae
• The Pectoral Girdle connects the arms to the body, positions the shoulders, and provides a base for arm movement
• The Upper Limbs consist of arms, forearms, wrists, and hands
• The forearm consists of the ulna (medial) and radius (lateral)
• The wrist consists of 8 carpal bones: 4 proximal carpal bones and 4 distal carpal bones
• The Pelvic Girdle is made up of 2 hipbones (ossa coxae) and is strong to bear body weight and stress of movement
• The Female Pelvis is smoother, lighter, has less prominent muscle/ligament attachments, and a greater angle of opening compared to the Male Pelvis
• The Lower Limbs function in weight bearing and motion
• Major bones of the Lower Limbs

  • Femur (thigh)
  • Patella (kneecap)
  • Tibia and fibula (leg)
  • Tarsals (ankle)
  • Metatarsals (foot)
  • Phalanges (toes)
• The Femur is the longest, heaviest bone
• Structure of the bone