Locomotion and movement

• Dense regular connective tissue

  • Tendons- collagen always exists in bundles parallel to each other
  • Ligaments- Elastin is formed in the same direction of fibres
• Body cells

  • Muscular movt- contractility, extensibility elasticity, excitability. The ability to respond to a stimuli and generate action potential to conduct an impulse
  • Ciliary movt
• Ciliary movt

  • Simple cuboidal and columnar epithelium( not squamous) show hair like outgrowth from the apical/free surface of the cell
  • Arise from the basal body below the cell membrane
  • Made up of Microtubules
  • Inner lining of fallopian tube, trachea, bronchi, bronchioles
• Location

  • Skeletal
  • Visceral
  • Cardiac
• Structure

  • Striated( Skeletal+ cardiac)
  • Unstriated/smooth(Visceral)
• Function

  • Voluntary(Skeletal)-CNS
  • Involuntary (Visceral+cardiac)-ANS
• Actin

  • Polymer
  • Many G actin ->F actin
  • 2 F actin wind together to form 1 active filament called subfilament
  • Func of Tropomyosin: stabilises actin filament
  • Func of Troponin: In resting muscle it masks the active myosin binding sites on actin
• Myosin

  • Polymer
  • Monomer->Meomyosin divided into heavy meromyosin (HMM)and light meromyosin (LMM)
  • The HMM is divided into Head and short arm which together form a cross arm
  • The LMM is further divided into tails
  • 2 units of Meromyosin make 1 myosin molecule and many myosin molecules make 1 myosin fibre
  • There is a potential difference between the neuronal membrane and sarcolemma, at rest this is termed as resting membrane phase. When a stimulus comes to the neuronal membrane a depolarisation takes place followed by a repolarisation and then RMP( resting membrane potential)
• Motor unit

  A single motor neuron+ all the muscle fibres it innervates.

  Path:

  1. Neural signal starts from CNS
  2. Motor neuron to cyton to axon to axon terminals to synaptic knob to sarcolemma to neuromuscular junction or motor end plate