ANIMAL MOVEMENT AND MUSCULAR PHYSIOLOGY

• Most animal movement depends on a single

  fundamental mechanism: contractile

  proteins, which can change their form to

  allow relaxation and contraction
• The most important protein contractile

  system is the actomyosin system,

  composed of two proteins, actin and

  myosin
• A form of movement especially

  characteristics of amoebas and other

  unicellular forms; amoeboid movement
• amoeboid movement is found in many wandering cells
• pseudopodia means “false feet”
• in cell migration in amoeba, The protruding of pseudopodia driven by the

  aggregation and activation of the adhesion

  complex
• in cell migration of amoeba, Formation of new adhesions driven by actin filaments
• in cell migration of amoeba, The adhesive

  contact of cell tail is broken by extracellular

  proteolytic enzymes such as MMPs to end

  the movement of cell crawling.
• Cilia is a minute, hair-like, motile structure that

  extend from surfaces of cells of many

  animals
• functions: to move unicellular organisms

  through their aquatic environment e.g.

  paramecium
• function: to propel fluids and materials

  over epithelial surfaces of larger animals

  e.g. trachea of humans
• Flagella is a whip-like structure longer than a cilium, found in many single-celled eukaryotes, in animal spermatozoa, and in sponges
• flagella if for function: for locomotion
• structure of eukaryotic flagellum; microtubule-

  associated proteins (MAPs) of the 9+2 arrangement typical of both cilia and flagella.
• The main difference between a cilium and a

  flagellum is in their beating pattern.
• A flagellum beats symmetrically with

  snakelike waves so that water is propelled

  parallel to the long axis of the flagellum.
• A cilium, in contrast, beats asymmetrically

  with a fast power stroke in one direction
• All muscle cells are elongated (muscle)

  fibers
• myo and mys (muscle) and sarco

  (flesh)
• Myology - the scientific study of muscles
• Three types of vertebrate muscles:

  skeletal, cardiac, smooth
• Muscular Tissues -differ from one another in their microscopic anatomy, location, and how they are controlled by the nervous system and endocrine systems
• Smooth Muscle

  • Fibers thickest in middle, tapered at each end,

  and with one centrally positioned nucleus; not

  striated
• Cardiac Muscle

  • branched cylindrical fiber with one centrally

  located nucleus; intercalated discs join neighboring

  fibers; striated
• Skeletal Muscle

  long cylindrical fiber with many peripherally

  located nuclei; unbranched; striated.

  • most commonly attached by tendons to bones
• TYPES OF INVERTEBRATE MUSCLE

  • smooth, striated, and oblique striated muscles
• in molluscs; striated muscle that can contract

  rapidly, enabling the bivalve to snap shut its valves when disturbed
• in molluscs; smooth muscle, capable of slow, long-lasting contractions. Using these fibers, a bivalve can keep its

  valves tightly shut for hours or even days
• Tropomyosin

   a protein that winds around the chains of

  the actin filament and covers the myosin-

  binding sites to prevent actin from binding to

  myosin

   binds to troponin to form a troponin-

  tropomyosin complex
• The troponin-tropomyosin complex prevents the

  myosin “heads” from binding to the active sites on

  the actin microfilaments.
• contraction of smooth muscle; contraction has MLCK (myosin light chain kinase)
• contraction of smooth muscle; relaxation has MLCP (myosin light chain phosphate)
• There are three mechanisms by which ATP can be

  regenerated:Creatine phosphate metabolism

  2. Anaerobic glycolysis

  3. Fermentation and aerobic respiration
• There are three mechanisms by which ATP can be

  regenerated:

  1. Creatine phosphate metabolism

  2. Anaerobic glycolysis

  3. Fermentation and aerobic respiration
• Creatine Phosphate

  a molecule that can store energy in its phosphate

  bonds, This acts as an energy reserve that can be used

  to quickly create
• Creatine Phosphate can only provide approximately 15 seconds worth of energy, at which point another energy source has to be used
• Aerobic Glycolysis

  • Each glucose molecule produces two ATP and

  two molecules of pyruvic acid, which can be used in

  aerobic respiration or converted to lactic acid.
• If oxygen is not available, pyruvic acid is

  converted to lactic acid, which may contribute to

  muscle fatigue during strenuous exercise when

  high amounts of energy are needed but oxygen

  cannot be sufficiently delivered to muscle.
• Fermentation and Aerobic Respiration

  • Aerobic respiration is the breakdown of glucose in

  the presence of oxygen (O2) to produce carbon

  dioxide, water, and ATP.
• Approximately 95 percent of the ATP required for

  resting or moderately active muscles is provided by

  aerobic respiration, which takes place in

  mitochondria.