Musculoskeletal System

• What systems work together to support and move the body?

  The muscular and skeletal systems
• What is the role of the skeleton in the body?

  It gives shape and form to the body and prevents soft tissues from collapsing
• How do muscles attached to bones enable movement?

  They can move bones or hold them steady
• What are the three types of muscle?

  Cardiac, smooth, and skeletal muscles
• What are the properties shared by all types of muscle?

  • Contractibility
  • Extensibility
  • Elasticity
  • Excitability
• What is the primary function of skeletal muscle?

  To enable movement by contracting at joints
• What type of muscle is under conscious control?

  Skeletal muscle
• What is the characteristic appearance of skeletal muscle?

  It is striated (has striations/stripes)
• What is the function of smooth muscle?

  To allow movement in many internal organs
• What is the primary function of cardiac muscle?

  To contract and push blood out of the heart
• What are the structural components of skeletal muscle?

  • Bundles of muscle fibers (cells)
  • Connective tissue (perimysium and epimysium)
  • Tendons
• What surrounds muscle bundles and allows them to slide over one another?

  Connective tissue called perimysium
• What is the function of epimysium in skeletal muscle?

  It holds all the bundles of muscle fibers together
• What is a muscle fiber also known as?

  A muscle cell
• What are myofibrils composed of?

  Myofilaments made of protein
• What are the two types of myofilaments?

  Thick myofilaments (myosin) and thin myofilaments (actin)
• What happens during muscle contraction according to the sliding filament theory?

  Thick and thin filaments slide past each other, shortening the sarcomere
• What is the role of calcium ions during muscle contraction?

  They unblock actin binding sites
• What is a cross bridge in muscle contraction?

  It is when myosin heads bind to actin
• What is the power stroke in muscle contraction?

  It is when the myosin head bends and pulls the actin
• What happens to the Z lines during muscle contraction?

  They move closer together
• What is the role of tendons in muscle movement?

  They pull on bones when a muscle contracts
• What are antagonistic pairs of muscles?

  • Pairs of muscles that produce movement in opposite directions
  • Example: Biceps (agonist) and triceps (antagonist)
• What is the origin of a muscle?

  It is the end of the muscle fixed to the stationary bone
• What is the insertion of a muscle?

  It is the end of the muscle fixed to the movable bone
• What is the belly of a muscle?

  It is the thick fleshy part in the middle of the muscle
• What are synergist muscles?

  They help the prime mover function more efficiently
• What is muscle tone?

  It is the maintaining partial contraction of skeletal muscles
• How does muscle tone affect posture?

  It helps hold body parts in position
• What are the key terms related to muscle anatomy and function?

  • Antagonist: Muscle with an action opposite to that of the agonist
  • Origin: Fixed end of the muscle
  • Insertion: Moveable end of the muscle
  • Belly: Fleshy portion in the middle of the muscle
  • Agonist: Muscle that causes the desired action
  • Synergist: Muscle that helps the prime mover
  • Fixator: Muscle that immobilizes a joint
  • Flexor: Muscle that bends joints
  • Extensor: Muscle that straightens joints
• What are the functions of the skeleton?

  Support, movement, protection, storage, and blood cell production
• How does the skeleton provide support?

  It provides a firm framework giving shape to the body and supports its parts
• What role does the skeletal system play in movement?

  It allows bones to move relative to each other with the assistance of muscles
• What vital organs does the skeletal system protect?

  The brain and spinal cord
• What minerals are primarily stored in bones?

  Calcium, phosphorus, sodium, and potassium
• What is the function of red bone marrow?

  It produces blood cells
• What are the components of the axial skeleton?

  • Skull
  • Vertebral column
  • Ribs
  • Sternum
• What is the function of the axial skeleton?

  • Provides main support for posture
  • Protects central nervous system and thoracic organs
• What are the components of the appendicular skeleton?

  • Upper and lower limbs
  • Pectoral girdle
  • Pelvic girdle
• What is the function of the appendicular skeleton?

  • Allows for articulation of the limbs with the axial skeleton