Muscular

• All muscles begin the actual process of contraction or shortening when a protein called actin is pulled by myosin.
• Skeletal Muscles -

  • Attach to and move skeleton
  • 40% of body weight
  • Fibers=long, cylindrical and multinucleate cells
  • Cells with striations
  • Contractions are strong, quick discontinuous and voluntary
• Arrangement of contractile proteins happens that created striations
• Cardiac Muscle -

  • Found only in the wall of the heart
  • Cells are striated and branched
  • With intercalated disc and 1 nucleus in-between
  • Contractions are strong, quick continuous and involuntary
• Smooth Muscles -

  • Found in walls of hollow organs
  • Lack striations
  • Spindle shaped; uninucleate
  • Contractions are weak, slow and involuntary
  • Singular nucleus because there are no contractions
  • Line the visceral organs
• Muscle fibers - Individual cells 
• Epimysium - Dense connective tissue
• Fascia - a connective tissue outside of epimysium
• Fascicle - bundle of muscle fibers
• Perimysium - surrounds the fascicle
• Endomysium - is a delicate network of connective tissue, which surrounds individual muscle fibers and contains the vessels and nerves that supply the muscle fibers as well as the proteoglycan matrix for ion flux and metabolic exchange.
• Myofibril - individual contractile units that receives nerve impulses from the brain
• Myosin is the thicker while actin is the thinner fiber
• Chordamesoderm

  • Notochord
• Paraxial Mesoderm

  • Head mesenchyme
  • Somites- block of cells (sclerotome, myotome, dermatome)
• Intermediate Mesoderm

  • Urogenital organs
• Lateral Plate Mesoderm

  • Splanchnic (viscera)
  • Somatic (Body wall)
  • Extraembryonic
• Skeletal Muscles

  • Myotome somites of paraxial mesoderm except the heads and limbs
  • Head and limbs muscles (general mesoderm)
  • Formed from general mesoderm
• Smooth and Cardiac Muscles

  Smooth and cardiac muscles

  • Splanchnic mesoderm
• Myoblasts -a muscle forming cells that migrates that forms a myotubes
• Satellite cells are important in cooperating in the muscle cells and facilitate protein synthesis required for growth and repair. 
• Sarcolemma- cover each muscle fibers
• Smooth muscle repair: Pericyte

  • Found in some blood vessels
  • Regenerate and repair more redly compare to skeletal muscles and cardiac muscles
• Type 1: Slow Twitch

  • Aerobic, oxidative metabolism
• Type 2A: Intermediate fast-twitch

  • Aerobic, oxidative and anaerobic, glycolytic metabolism
• Type Type 2B: Fast-twitch fibers

  • Anaerobic, glycolytic metabolism
• Myoglobin -oxygen binding protein found in the blood that gives the muscle reddish in color.
• Soleus muscle- one muscle that has many slow twitch muscle fibers, found in the leg that gives a key role in standing. 80% percent are slow-twitch.
• 1. Somatic/Skeletal- orient body to environment; striated; attached to axial & appendicular skeleton and to lateral & ventral body walls; innervated by spinal nerves; voluntary; derived from myotomes (epimeres)
• 1. Visceral- maintain appropriate internal milieu; derived from splanchnic mesoderm;innervated postganglionic fibers of ANS
• Smooth muscles - hollow organs, vessels, tubes, ducts; intrinsic eyeball muscles; erector muscles of hair and feather
• Cardiac muscles- of heart; with striations but branched
• Branchiomeric Somatic Muscles - of pharyngeal arches; striated skeletal; myotomal from anterior stomates and unsegmented paraxial mesoderm; innervated by cranial nerves
• • Origin (anatomic)= fixed point of attachment;
• • Insertion= usually displaced by muscle contraction; more movable point
• • Insertion= usually displaced by muscle contraction; more movable point
• Aponeurosis= tough, thin sheetlike expanses of mammalian tendons and ligaments;
• Aponeurosis -

  • Absorbing energy during movement
• Raphe =long, seamlike tendon; e.g. linea alba (trunk)
• 1. Extensors and Flexors (Paired antagonistically in action)-Extend and flex