GEN BIO 2 WEEK 6 Q4

• Musculoskeletal System


  The system that provides support, structure, and movement to the body
• Skeletal System


  • Provides support and protection
  • Produces blood cells
  • Stores minerals
• Cellularity


  The percentage of blood cells produced in different organs during development
• Types of Skeleton


  • Exoskeleton - bony structure found externally (vertebrate) - skin derivatives [dermis and epidermis]
  • Endoskeleton - bony structure found internally
• Types of Exoskeleton


  • Chitin exoskeleton
  • Calcium carbonate exoskeleton
• Classification of Bones by Location


  • Axial skeleton - located in the median axis of the body
  • Appendicular skeleton - located at the sides of the body
• Classification of Bones by Shape


  • Long bones - elongated and cylindrical
  • Short bones - small and cubed
  • Irregular bones - varied shapes that permit connections with other bones
  • Round bones - circular in shape
  • Flat bones - platelike with broad surfaces
• Tendon


  Connects muscle to bone
• Ligament


  Connects bone to bone
• Cartilage


  Flexible connective tissue found in many areas of the body, stiffer and less flexible than muscle
• Bone Cells


  • Osteoblast - responsible for secreting matrix, ostein
  • Osteoclast - performs bone reabsorption
• Types of Muscles


  • Smooth Muscles - act on the lining of the body's passageways and hollow internal organs
  • Cardiac Muscles - forms the wall of the heart and responsible for the contraction of the heart
  • Skeletal Muscles - muscles attached to bone that cause body movements
• How Muscles Work


  1. Biceps contracted, triceps relaxed (extended)

  2. Triceps contracted, biceps relaxed
• Origin


  The end of a muscle that does not move
• Insertion


  The end of a muscle that moves when the muscle contracts
• Muscle Movements


  • Adduction - moving body part toward the midline
  • Abduction - moving body part away from midline
  • Flexion - decreasing the angle between two bones or bending a body part
  • Extension - increasing the angle between two bones or straightening a body part
  • Rotation - turning a body part around its own axis
  • Circumduction - moving in a circle at a joint
• Cellulose


  A polysaccharide that makes up the cell wall of plants
• Plants do not have muscles, but they do have motor cells in the region where the leaf connects to the stem
• 15 years of age in girls and 16 in boys


  Longitudinal growth of bone continues until approximately