muscles and joints

• Skeletal muscle


  • Fibers: striated, tubular and multi nucleated
  • Voluntary
  • Usually attached to skeleton
• Smooth muscle


  • Fibers: non-striated, long spindle-shaped & uninucleated
  • Usually covering wall of internal organs
• Cardiac Muscle


  • Fibers: striated, branched and uninucleated
  • Involuntary
  • Covers the walls of the heart
• Voluntary muscles are made up of striped muscle fibers
• Skeletal Muscles Have 2 or more attachments Origin (moves least) Insertion (moves most)
• Skeletal Muscle Actions

  • Prime Movers - a CHIEF mm or member of a chief group of muscles responsible for a particular movement
• Nerve Supply of the Skeletal Muscle

  • The nerve supply to SM is a mixed nerve, about 60% is motor and 40% is sensory, and also contains some sympathetic autonomic fibers
• Smooth Muscles


  • Tubes of the body, provide the motive power to propel the contents through the lumen
  • Digestive tract, causes the ingested food to be thoroughly mixed with the digestive juices
  • Storage organs, the fibers are irregularly arranged and interlaced with one another
  • Blood vessel walls, they are arranged circularly and serve to modify the size of the lumen
• Cardiac Muscles


  • Striated muscle fibers that branch and unite with each other, this forms the myocardium of the heart
  • Its fibers tend to be arranged in whorls or spirals
  • Supplied by autonomic nerve fibers that terminate in the nodes of the conducting system and in the myocardium
• Joints


  A site where two or more bones come together
• Fibrous Joint Directly connected to each other by fibrous connective tissue. Very little mov't takes place
• Articular Discs found in the knee such as the meniscus
• Bursa - found in the elbows and knees, small sacs lined with synovial membrane and filled with synovial fluid, the bursae acts to

  reduce friction caused by contraction.
• Ball and Socket Joints - a ball like head of a bone

  fits into the socket-like concavity of another.
• Hinge Joint - resemble the hinges of a door
• Pivot Joint - a central bony pivot is surrounded by a bony ligamentous ring, allowing only rotational movements
• Saddle Joint -  the articular surfaces are reciprocally concave/convex, resembling a saddle on a horse’s back.
• Plane Joint - Apposed articular surfaces are flat or almost flat, permits the bones to slide on one another
• • Ellipsoid Joint An elliptical convex articular surface fits into an elliptical concave articular surface.
• Two types of Cartilaginous Joints Primary and Secondary
• Primary:bones are united by a plate or a bar of hyaline cartilage. Non moveable joints.
• Secondary: bones are united by a plate of fibrocartilage and the articular surfaces of the bones are covered by a thin layer of hyaline cartilage, allowing slight mov’t.
• • Motor Point - place of entrance in which the nerve embeds itself into the muscle, located at the midpoint on its deep surface, often near the margin
• Articular capsule - contains a fibrous layer which helps to stabilize the joint and a synovial layer which secretes synovial fluid and absorb impact external to the joint
• Articular surface - covered in hyaline cartilage which reduces friction and assists in shock absorption.
• • Fixators - Contracts isometrically (increases tone but does not produce movement) to stabilize the origin prime mover so that it can act efficiently
• • Synergist - Prevents unwanted mov't as they stabilize intermediate joints
• • Antagonist - Any mm that opposes the action of the prime mover
• Muscle Belly - the fleshy part of the muscle
• • Tendons - ends of a muscle are attached to ligaments, cartilage, or ligaments by cords of fibrous tissue
• Aponeurosis - flattened muscles are attached by a thin but strong sheet of fibrous tissue
• • Raphe - is an interdigitation of of the tendinous ends of fibers of flat muscles
• Types of muscle fibers: Skeletal muscle, cardiac muscle, smooth muscle
• Cardiac Muscles - involuntary; found only in heart; branching cells with cross-striations
• Smooth Muscles - involuntary; found in walls of hollow organs (e.g., stomach); spindle-shaped cells with no striations
• Skeletal Muscles - voluntary; attach to bones; long cylindrical cells with cross-striations
• Smooth Muscles - involuntary; found in walls of hollow organs; no striation
• Skeletal Muscles - voluntary; attach to bones; have striations
• Tendon - muscle to bone
• Ligaments 

  • is a cord or band of connective tissue uniting structures commonly found in assoc. with joints.