BIO LESSON 1

• Muscular and skeletal systems


  • Provide support to the body and allow for a wide range of movement
• Muscular system


  Contracts and pulls the bones allowing for movement
• Skeletal system


  Supports the body, protects internal organs, and allow body movement
• Three different skeleton designs

  • Hydrostatic skeleton
  • Exoskeleton
  • Endoskeleton
• Hydrostatic skeleton


  • Formed by a fluid-filled compartment within the body, called coelom
  • Supported by aqueous fluid, which resists external compression
  • Found in soft-bodied animals such as sea anemones, earthworms, cnidaria, and other invertebrates
• Exoskeleton


  • An external skeleton that consists of a hard encasement on the organism
  • Provides defense
  • Consists of chitin - strong but flexible material secreted by epidermal cells
  • Arthropods have 30-50% chitin and periodically shed their exoskeleton (molting)
• Endoskeleton


  • Consists of hard, mineralized structures located within the soft tissue of organisms
  • Human skeletal system has 206 bones
• Divisions of the skeletal system

  • Axial skeleton
  • Appendicular skeleton
• Axial skeleton


  Provides protection to vital internal organs; includes skull, vertebral column, and rib cage
• Appendicular skeleton


  Engages movement; includes bones that attached to the axial
• Types of skeletons


  • Endoskeleton
  • Exoskeleton
  • Hydrostatic skeleton
• Endoskeleton


  Consists of bones, cartilage, muscles, tendons, and ligaments
• Exoskeleton


  Consists of a hard outer shell
• Hydrostatic skeleton


  Fluid filled cavities surrounded by muscle
• Types of muscle tissue

  • Skeletal muscle
  • Smooth muscle
  • Cardiac muscle
• Cardiac muscle


  • Only found in the heart; striated but involuntary
  • Pump blood throughout the body and maintain blood pressure
  • One nucleus per cell and distinguished by the presence of intercalated discs
• Smooth muscle


  • Occurs in the walls of hollow organs such as intestines, stomach, and urinary bladder
  • No striations, spindle-shaped and involuntary
• Skeletal muscle


  • Attach to bones or skin for control locomotion and movement (voluntary muscles)
  • Long and cylindrical in appearance
  • Striped or striated – under the microscope
  • Striations caused by the arrangement of contractile proteins (actin and myosin)
• Muscular and skeletal systems


  • Provide support to the body and allow for a wide range of movement
• Muscular system


  Contracts and pulls the bones allowing for movement
• Skeletal system


  Supports the body, protects internal organs, and allow body movement
• Three different skeleton designs


  • Hydrostatic skeleton
  • Exoskeleton
  • Endoskeleton
• Hydrostatic skeleton


  • Formed by a fluid-filled compartment within the body, called coelom
  • Supported by aqueous fluid, which resists external compression
  • Found in soft-bodied animals such as sea anemones, earthworms, cnidaria, and other invertebrates
• Exoskeleton


  • An external skeleton that consists of a hard encasement on the organism
  • Provides defense
  • Consists of chitin - strong but flexible material secreted by epidermal cells
  • Arthropods - 30-50% chitin and periodically shed their exoskeleton (molting)
• Endoskeleton


  • Consists of hard, mineralized structures located within the soft tissue of organisms
  • Human - 206 bones
• Divisions of the skeletal system


  • Axial skeleton
  • Appendicular skeleton
• Axial skeleton


  Protection to vital internal organs; skull, vertebral column, and rib cage
• Appendicular skeleton


  Engage movement; bones that attached to the axial
• Types of skeletons


  • Endoskeleton
  • Exoskeleton
  • Hydrostatic skeleton
• Endoskeleton


  Consists of bones, cartilage, muscles, tendons, and ligaments
• Exoskeleton


  Consists of a hard outer shell
• Hydrostatic skeleton


  Fluid filled cavities surrounded by muscle
• Types of muscle tissue


  • Skeletal muscle
  • Smooth muscle
  • Cardiac muscle
• Cardiac muscle


  • Only found in the heart; striated but involuntary
  • Pump blood throughout the body and maintain blood pressure
  • One nucleus per cell and distinguished by the presence of intercalated discs
• Smooth muscle


  • Occurs in the walls of hollow organs such as intestines, stomach, and urinary bladder
  • No striations, spindle-shaped and involuntary
• Skeletal muscle


  • Attach to bones or skin for control locomotion and movement (voluntary muscles)
  • Long and cylindrical in appearance
  • Striped or striated - under the microscope
  • Striation - caused by the arrangement of contractile proteins (actin and myosin)
• Muscular and skeletal systems


  • Provide support to the body and allow for a wide range of movement
• Muscular system


  Contracts and pulls the bones allowing for movement
• Skeletal system


  Supports the body, protects internal organs, and allow body movement
• Three different skeleton designs


  • Hydrostatic skeleton
  • Exoskeleton
  • Endoskeleton