Skeletal System 

  1. Five major functions of the skeletal system
  • support: body structure and shape 
  • protection: vital organs ‘surrounded’
  • movement/anchorage for muscles
  • mineral storage: calcium and phosphorus
  • blood formation
  1. 5 categories of bones
  • long bones: longer than they are wide (humerus)
  • short bones: generally cube shaped (carpals & tarsals)
  • flat bones: “plates” (scapula)
  • irregular bones: vary in shape and size (vertebrae)
  • regular bones: also called “sesamoid” usually embedded in connective tissue (knee cap)
  1. Anatomical parts of long bones, including structure and function

  • Periosteum: fibrous connective tissue around bone, has ligaments and tendons, vascular function

  • Epiphysis: ends of bones, red bone marrow, blood cell generation

  • Diaphysis: shaft of the bone, yellow bone marrow, houses medullary cavity

  • Articular Cartilage: hyaline cartilage found in areas where bones meet, protects the bone ends

  • Compact: closely packed osteons, provides strength and protection to bones

  • Spongy (Cancellous) Bone: consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow

 

  1. Oorganization of the Haversian systems (osteons) within bones
  • Haversian Systems: made of osteons, cylindrical units that contain osteocytes in lacunae, central canal and canaliculi 
  1. Four cell types involved in bone growth and repair

  • Osteoprogenitor Cells: unspecialized cells (stem cells), controls bone remodeling

  • Osteoblasts: derived from osteoprogenitor cells, secrete lamellae (matrix)

  • Osteocytes: derived from osteoblasts, becomes osteocytes when surrounded by matrix 

  • Osteoclasts: specialized cell that absorbs and removed bone, more cellular structure

  1. The two ossification processes used in bone formation
  • Intramembranous Ossification: the direct deposition of bone on thin layers of connective tissue to make ‘non long bone’. There are then three stages to do so. 
  • Endochondral Ossification: most common type of bone formation in humans, the replacement of hyaline cartilage with bone, there are 6 steps of this process. \n
  1. Appositional growth and bone remodeling
  • Appositional Growth: increases the width of bones after endochondral growth
    • osteoprogenitor cells convert to osteoblasts, lay more matrix and then convert to osteocytes
  • Bone Remodeling: bones are regularly broken down by osteoclasts and reformed by osteoblasts. 
  1. Two types of reductions used to repair fractured bones
  • Closed Reduction: realignment of bone without surgery
  • Open Reduction: needs surgery to repair bone
  1. Explain the steps that result in bone repair
  • Break area is filled with blood, becomes a large clot
  • Fibrocartilaginous callus replaces the blood clot
  • Osteoblasts convert the fibrocartilaginous callus into bony callus
  • Break area is remodeled, new medullary cavity is formed
  1. Different types (categories) of bone breaks
  • Complete: bone is fractured in 2 pieces
  • Incomplete: broken but not in 2 pieces
  • Simple: fractured bone does not break skin
  • Compound: fractured bone breaks skin
  • Impacted: impact force breaks bone, wedges it into each other
  • Spiral: break caused by severe twisting
  1. Know the two systems used to identify/name joints.
  • Movement: based on the amount of movement they allow
  • Structure: based on the structure
  1. Fibrous vs Cartilaginous vs Synovial joints.  What’s the difference, in terms of structure?
  • Fibrous: fibrous connective tissue joins the two bones
  • Cartilaginous: hyaline cartilage or fibrocartilage join the bones
  • Synovial: encompassed by a fibrous capsule with a synovial lining
  1. Know the structural parts of a synovial joint.
  • Synovial Membrane: lines joint cavity
  • Synovial Fluid: lubricant for the joint
  • Joint Capsule: surrounds and stabilizes the joint
  • Ligament: additional stabilization
  1. Be able to identify each type of synovial joint, including the type of motions involved with each.
  • Saddle: lots of motion possible
  • Ball and Socket: rotation and movement motion
  • Pivot: rotational motion 
  • Hinge: up and down motion
  • Gliding: sliding/twisting motion 
  • Condyloid: planar movement