MASCULAR SYSTEM

• Muscular system


  Comprises organs associated with functions in the body
• Bones


  • Considered to be connective tissues
• Muscular tissues


  • Specialized with the aspect of locomotion
  • Not all muscles are associated with movement
  • Can be found in the body which has different functions and these are predominantly functioning
• Digestive system


  • Responsible for the food itself
  • Extraction of nutrients from the food
  • Provides the body with necessary chemicals (nutrition)
• Muscular system


  • Can only transform nutrients that can turn it into energy
  • Destroys fat to use muscle
• Functions of the muscular system

  • Voluntary motor function
  • Involuntary motor function
• Voluntary motor function


  Conscious functions of the body
• Involuntary motor function


  Cannot be controlled
• The cells of the muscular system are very different due to appearance and shape
• The muscular system cannot sustain itself without the aid of other cells in the body
• Primary connection between muscular system and nervous system

  • Neuromuscular junction
  • It passes through the muscle before the brain
• Diaphragm


  • Inhale and exhale muscle
  • Helps the organs to function
• Utilization of ATP


  • Into physiological functions (contraction or motor signaling)
  • ATP (adenosine triphosphate) is used by the muscles
  • It can transform ATP directly into heat
• Physiologic response of muscle when cold

  Shivering (muscles generate heat)
• Thermogenesis


  • Muscles of our body maintain the body heat
  • Muscles create heat in the body
• Thermoregulation


  • Not associated with muscle
  • Heat control is the skin
  • Excessive heat is released through sweating/perspiration
• Types of muscles


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


  • Attached to the bones
  • Tubular
  • Sarcomeres (cylindrical found in the muscle)
  • Muscle fibers shorten/stiffen when flexing
• Cardiac muscle


  • Branched
  • Capacity of heart (Autorhythmicity)
  • Can be controlled up to a certain extent
• Smooth muscle

  • Spindle shaped
  • Look like the shape of the eyes
  • Lack of bands
  • Involuntary actions
  • Does not shorten
  • Can be found in the internal organs (stomach and intestines)
• Parts of the muscular system

  • Tendon
  • Muscle bundle
  • Muscle fasciculi
  • Muscle fiber
• Tendon

  • Connective tissue related to regular collagenous
  • Maintain the position of the muscle
• Muscle bundle


  • Whole muscle
  • Covered by the Epimysium like a plastic cover
• Muscle fasciculi


  Covered by the Perimysium
• Muscle fiber


  Covered by the Endomysium
• The muscle fibers need to be organized, they will disintegrate if there is no covering, the multiple coverings keep them whole
• Sarcomeres can only be determined with the bands (Z disk, M line)
• Contracted condition


  When M line is short to the Z disk
• Myofilaments in each sarcomere

  • Actin
  • Myosin
• Actin and Myosin

  They want to be together (like a couple)
• Actin


  Thin filament
• Myosin


  Thick filament
• Actin

  • Tropomyosin (prevents)
  • Troponin (want to be together)
• Innervation of muscular system

  • Non-graded action potential (does not induce movement)
  • Graded action potential (induces movement of the muscles)
• Threshold

  At least 30mV (default is -70mV, +30mV opens voltage gated channels)
• Acetylcholine

  Molecules when the calcium has entered the nerve
• Synaptic cleft

  Connections of the neurons to the muscle
• Acetylcholine receptor

  • Pink
  • Inactivates the muscle
• Calcium

  Attaches to troponin
• Muscle contraction

  1. Actin/active site falls off

  2. Actin and myosin interact

  3. Myosin removes ATP to ADP (cross bridging)

  4. Myosin pushes actin forward (power stroke) until actin is in the middle