Wipe down work area with tabletop disinfectant

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• Wipe down work area with tabletop disinfectant
• Announcements
• Todays Lab Introduction to Muscles and Muscle
  Histology
• Tuesdays Lab Quiz 4 (covering CT, joints,
  major muscles and muscle histology)
• Begin Cat Dissections, Muscles of the Chest and
  Back (Ex.11 and 14)
• Next Thursday Above Muscles continued, plus
  Muscles of Abdomen and Arm (Ex. 11 and 14)

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Lab 10 Introduction to Muscles and Muscle
Histology

• References
• Exercise 4 and 11
• Chapter 3 (p.94) and Chapter 10
• Lab outlines and handouts
• Human muscle models
• Penn State website, Get Body Smart website,
  Charlie Harrisons website, Human Body Atlas,
  AMAs website

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• Muscle Nomenclature p. 144 lab manual
• Direction of muscle fibers
• Size of muscle
• Location of muscle
• Number of origins
• Origin and insertion
• Shape of muscle
• Action of muscle

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For the practical exam know names (spelled
correctly), origin, insertion and action of all
muscles listed in lab outline
Origin - less movable / immovable, usually
proximal Insertion - more movable, usually
distal Agonist - Prime mover, muscle that bears
primary responsibility for a particular
movement Synergist - muscles that aid prime mover
by contributing to same movement or by preventing
undesirable movement Anatgonist - muscles that
oppose or reverse movement of prime mover
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Articulations and Body Movements Lab Manual
reference - page 136 - 138
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For Example Pectoralis Minor
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Learning Muscle Actions and Skeletal
Movements (see Get Body Smart website)
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• Muscle Tissue (myo-, mysi-)
• Functions
• Movement
• Skeletal muscle - attached to skeleton, moves
  body by moving the bones
• Smooth muscle squeezes fluids and other
  substances through hollow organs
• Maintain posture enables the body to remain
  sitting
• or standing
• Joint stabilization
• Heat generation muscle contractions produce
  heat,
• helps maintain normal body temperature

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Functional features Contractility long cells
shorten and generate pulling force Excitability
electrical nerve impulse stimulates the muscle
cell to contract Extensibility can be stretched
back to its original length by contraction of an
opposing muscle Elasticity can recoil after
being stretched
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• Vocabulary
• Muscle cells are known as fibers
• The functional contractile unit of a muscle fiber
  is called a sarcomere
• Plasma membrane is called the sarcolemma
• Cytoplasm is called sarcoplasm

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• Muscle contraction depends on two types of
  myofilaments (contractile proteins)
• One type contains actin (thin)
• Another type contains myosin (thick)
• These two proteins generate contractile force
• And, two types of regulatory proteins
• Act like a switch to determine when a muscle can
  contract and when it cannot
• Tropomyosin and troponin

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• The basic unit of contraction of skeletal muscle
• Z disc (Z line) boundaries of each sarcomere
• Thin (actin) filaments extend from Z disc
  toward the center of the sarcomere
• Thick (myosin) filaments located in the center
  of the sarcomere
• Overlap inner ends of the thin filaments
• Contain ATPase enzymes

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• A bands full length of the thick filament
• Includes inner end of thin filaments
• H zone center part of A band where no thin
  filaments occur
• M line in center of H zone
• Contains tiny rods that hold thick filaments
  together
• I band region with only thin filaments
• Lies within two adjacent sarcomeres

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• Sliding filament theory
• Myosin heads attach to actin in the thin
  filaments
• Then pivot to pull thin filaments inward toward
  the center of the sarcomere

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View Muscle Contraction
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• Three types of Muscle Tissue
• Skeletal muscle tissue packaged into skeletal
  muscles
• Makes up 40 of body weight
• Cells are striated
• Multiple peripheral nuclei
• Cardiac muscle tissue occurs only in the walls
  of the heart
• Cells are striated and branched
• Single central nucleus
• Intercalated disks (connections between cells)
• Smooth muscle tissue walls of hollow organs and
  vessels
• Cells lack striations
• Mononucleated

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Skeletal Muscle Tissue - 250X
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Skeletal Muscle Tissue - 400X
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Cardiac Muscle Tissue - 400X
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Smooth Muscle Tissue - 400X
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Smooth muscle NOT to be confused with ..
Dense Regular CT - 400X
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• View 3 types of muscle histology and complete
  study cards
• Locate major muscles on human models and practice
  learning origin, action and insertion
• Tuesdays Lab Quiz 4 Begin Cat Dissections,
  Muscles of the Chest and Back (Ex.11 and 14)
• Dont forget gloves, lab coat (or shirt), Vicks,
  etc.
• Next Thursday Above Muscles continued, plus
  Muscles of Abdomen and Arm (Ex. 11 and 14)