Muscular/bone System (Module 5)

Muscular/bone System (Module 5)

1. Skeletal Muscle

   • Voluntary
     • Stimulated by nerves
   • Striated
   • Multicleated
   • Function
     • Mainipulation of enviroment
     • Facial expression
     • Voluntary control
   • Location
     • In skeletal mucles attached to bone & skin
   • Description
     • Long cylindrical
     • obviuos striations

2. Cardiac Muscle

   • Involuntary
     • auto-rhythmic
   • Striated
   • Single Nucleus
   • Description
     • Branching
     • uninucleate cells that interdigitate at specialized junctions (intercalated discs.)
   • Function
     • As it contracts, it propels blood into the circulation
   • Location
     • Walls of the heart

3. Smooth Muscle

   • Involuntary
     • auto-rhythmic
   • Non-stiated
   • Multinucleated
   • Description
     • Spindle-shaped cells with central nuclei.
     • Cells arranged closely to form sheets
   • Function
     • propels substances along internal passage ways
   • Location
     • In walls of hollow organs

4. Functions

   • Movement
     • Skeletal muscle, bones & joints
   • Posture
     • Holding body in position
   • Moving substances in the body
     • Cardic mucle (heart)
     • Skeletal muscle (lympth/blood0
   • Regualting organ volume
     • Stomach, bladder
   • Heat Production
     • Muscle contraction

5. Charateristic of muscle

   • Excitability (irritabiity)
     • Ability to respond to stimulus
   • Contractility
     • Ability to contract when stimulated
   • Extensibility
     • Ability to be stretched or extended
   • Elasticity
     • Ability to return to the orgian length

6. Muscle attachment

   • Muscle contraction
     • Orgian-the end staying attached to the bone
     • Insertion-moved my the contraction

7. Movement

   • Antagonistic pairs
     • Agonist-prime mover contracts to cause action
     • Antagonist-stretches & yeilds to the action of agonist
     • Synergist-contract to stablise intermediate joints
     • Fixator-stablises the orgin of the agonist

8. Anatomy of Skeletal muscle

   • Made up of nundles of muscle fibres-Fascile
   • Muscle fibres held together by connect tissues (3)
     • Epimysium-surrounds whole muscle
     • Perimyium-surrounds the bundles of fibres
     • Endomysium-surrounds inidividual muscle fibres
   • Each fibre is made up of many Myofibrils
     • Contractile protiens
       • Actin-myosin-Myofilaments

9. Cross bridge Formation

   • Huxley Sliding Filament Theory
     • During muscle contraction/relaxation the actin & Myosin fiament slide past each other
       • Actin
         • Thin filaments consisting of 2 strands into a helix + 2 protiens (troponin & tropomysosin)
       • Myosin
         • Each thick filament consists of mysosin molecules that have a thick head to cling onto Actin.
     • 'Z discs' are on either end of the sarcomere (contract closely-relax futher away)
   • Requires calcium to bind the Tropomyosin protiens pulling them away from the myosin binding site on the actin filament.
     • Calcuim comes from-sarcoplasm of muscle cell/fibres
   • Requires large amounts of ATP
     • Large amounts of mitochondria in muscles

10. ATP

    • Anaerobic Respiration
      • Does NOT require o2
      • 2 stages
        • Glycolysis
        • Lactic acid formation
    • Aerobic Respiration
      • Requires O2
      • 3 Stages
        • Glycolysis
        • Krebs Cycle
        • Oxidative phosphorylation

11. Bones

    • Joints
      • Structual Classifcation
        • What binds the bone together
        • 2 types of bone
          • Spongy bone
          • Compact bone
      • Functiona Classifcation
        • How much the joint can move
    • Functions
      • Support
      • Protection
      • Movement
      • Mineral Homeostasis
      • Blood cell production
      • Fat storage