General Biology

• Cardiac Muscle

  • Main features: Striated, branched and uninucleated fibers
  • Involuntary muscle
  • Only covering walls of the heart
• Skeletal Muscles


  • Also known as voluntary muscles
  • Appearance: tubular fiber, striated muscles, and multi-nucleated cells (muscle fibers)
  • Function: Controls voluntary movement
  • Either attached to bone or connective tissue
• The muscle part of the heart is called the myocardium from myo (muscle) + kardia (heart)
• Cardiac Muscles

  • Also known as myocardium
  • Appearance: branched cylindrical-shaped, striated muscles, and uninucleated cells
  • Function: Controls involuntary movement to rhythmic heartbeat
• Function of Muscular System

  1. Creates body heat

  2. Moves bones of the Skeletal system

  3. Moves food through Digestive system

  4. Moves blood through Circulatory system

  5. Moves fluids through Excretory system
• Smooth Muscles

  • Also known as involuntary muscles
  • Appearance: spindle shape with tapered ends, non-striated muscles, and uninucleated cells
  • Function: Controls involuntary movement related to digestion, blood flow, urination, and breathing
  • Located in walls of hollow internal organs such as the intestines, blood vessels, bladder, and airways
• Muscles are attached to bones by tough cords of connective tissue called tendons
• Series of wave-like muscle contractions that move food through the digestive tract is called peristalsis
• Muscular Tissues

  • Comprised of elongated cells called muscle fibers, capable of contracting to produce movement
• Smooth Muscle

  • Main features: Non-striated, spindle-shaped, uninucleated fibers
  • Involuntary muscle
  • Usually covering wall of internal organs
• Location

  • 1: Skeletal
  • 2: Cardiac
  • 3: Smooth
• How do Skeletal Muscles Move?

  1. Muscle pairs are grouped together on the skeleton

  2. Skeletal muscles only pull in one direction and come in pairs

  3. When one muscle of a pair contracts, the other relaxes
• Skeletal Muscle

  • Main features: Striated, tubular and multi-nucleated fibers
  • Voluntary muscle
  • Usually attached to skeleton
• Muscle Type

  • Skeletal
  • Cardiac
  • Smooth