SKELETAL

• Skeletal system


  Components of the skeletal system: Cartilages, Bones, Tendons, Ligaments

  
• Cartilages


  • Types: hyaline, fibrocartilage, elastic
• Bones


  • Types: spongy, compact; long, short; flat, irregular

  
• Tendons

  Connect muscle to bone
• Ligaments


  Connect bone to bone

  
• Functions of the skeletal system

  • Framework and support
  • Gives the body shape
  • Protects and supports body organs
  • Movement
  • Storage of calcium and other minerals
  • Blood cell production
• Spongy bone


  Small needle-like pieces of bone with many open spaces

  
• Classification of bones based on shape

  • Long bones
  • Short bones
  • Flat bones
  • Irregular bones

  
• Long bones


  • Typically longer than they are wide, have a shaft with heads at both ends, contain mostly compact bone

  
• Long bones

  • Femur, Humerus

  
• Short bones


  • Generally cube-shaped, contain mostly spongy bone

  
• Short bones


  • Carpals, Tarsals
• Flat bones

  • Thin, flattened, and usually curved, two thin layers of compact bone surround a layer of spongy bone

  
• Flat bones


  • Skull, Ribs, Sternum

  
• Irregular bones


  • Irregular shape, do not fit into other bone classification categories

  
• Irregular bones


  • Vertebrae, Hip bones

  
• Factors affecting bone growth

  • Nutrition (Vitamin C, Vitamin D)
  • Hormones (Growth hormone, Thyroid hormone, Sex hormones)
• Osteocytes


  Mature bone cells
• Osteoblasts


  Bone-forming cells
• Osteoclasts


  Bone-destroying cells, break down bone matrix for remodeling and release of calcium in response to parathyroid hormone
• Types of bone growth

  • Appositional growth (formation of new bone on the surface of existing bone)
  • Endochondral growth (growth of cartilage in the epiphyseal plate and its eventual replacement by bone)

  
• Bone structure


  • Bone markings reveal sites of muscle attachment, points of articulation (joint), sites of blood vessels and nerve passage

  
• Diaphysis

  Shaft of a long bone

  
• Epiphyses


  Ends of a long bone

  
• Medullary cavity


  Contains yellow marrow
• Periosteum


  Covers the diaphysis
• Endosteum


  Lines inner bone cavities

  
• Hyaline cartilage


  Covers joint surfaces
• Parts of the skeletal system

  • Bones (skeleton)
  • Cartilages
  • Ligaments
  • Tendons
  • Joints

  
• Subdivisions of the skeleton

  • Axial skeleton
  • Appendicular skeleton

  
• Axial skeleton


  • Forms the longitudinal axis of the body, principal subdivisions are the skull, vertebral column, and bony thorax, provides support and protection

  
• Appendicular skeleton


  • Consists of the bones of the pectoral and pelvic girdles and the limbs, allows mobility for manipulation and locomotion

  
• Bones of the skull

  • 22 bones, base and vault formed by the cranium, facial skeleton provides openings for respiratory and digestive passages and serves as attachment points for facial muscles

  
• Facial bones


  • Maxillae, Zygomatics, Nasals, Lacrimals, Palatines, Inferior conchae, Mandible, Vomer

  
• Paranasal sinuses


  • Frontal bone, Ethmoid bone, Sphenoid bone, Maxillary bones

  
• Hyoid bone


  Supported in the neck by ligaments, serves as an attachment point for the tongue and neck muscles
• Foramen magnum


  Opening in the base of the skull or occipital bone where the spinal cord passes

  
• Cranial sutures


  Fibrous joints connecting the bones of the skull, fixed and immovable (in adults), no cavities

  
• Vertebrae of the vertebral column

  • 24 movable vertebrae: 7 cervical, 12 thoracic, 5 lumbar, sacrum, coccyx
• Primary curvatures of the vertebral column

  Thoracic, Sacral