EDU2HBS Human Body Systems 1 The Muscular System 2

EDU2HBS Human Body Systems 2 Energy for Muscle Contraction  Initially, muscles used stored ATP for energy  Bonds of ATP are broken to release energy  After this initial time, other pathways must be utilized to produce ATP

EDU2HBS Human Body Systems 3 Energy for Muscle Contraction  Direct phosphorylation  Muscle cells contain creatine phosphate (CP) After ATP is depleted, ADP is left  CP transfers energy to ADP, to regenerate ATP  CP supplies are exhausted in about 20 seconds

EDU2HBS Human Body Systems 4 Energy for Muscle Contraction  Aerobic Respiration  Series of metabolic pathways that occur in the mitochondria  This is a slower reaction that requires continuous oxygen

EDU2HBS Human Body Systems 5 Energy for Muscle Contraction  Anaerobic glycolysis  Glucose is broken down to pyruvic acid to produce some ATP  Pyruvic acid is converted to lactic acid

EDU2HBS Human Body Systems 6 Energy for Muscle Contraction  Anaerobic glycolysis (continued)  This reaction is not as efficient, but is fast  Huge amounts of glucose are needed

EDU2HBS Human Body Systems 7 Muscle Fatigue and Oxygen Debt  The common reason for muscle fatigue is oxygen debt  Oxygen must be “repaid” to tissue to remove oxygen debt  Oxygen is required to get rid of accumulated lactic acid  Increasing acidity (from lactic acid) and lack of ATP causes the muscle to contract less

EDU2HBS Human Body Systems 8 Types of Muscle Contractions  Isotonic contractions  The muscle shortens  Isometric contractions  Tension in the muscles increases  The muscle is unable to shorten

EDU2HBS Human Body Systems 9 Muscle Tone  Different fibers contract at different times to provide muscle tone  The process of stimulating various fibers is under involuntary control

EDU2HBS Human Body Systems 10 Muscles and Body Movements

EDU2HBS Human Body Systems 11 Muscles and Body Movements  Muscles are attached to at least two points Origin Insertion

EDU2HBS Human Body Systems 12 Effects of Exercise on Muscle  Results of increased muscle use

EDU2HBS Human Body Systems 13 Types of Ordinary Body Movements  Flexion  Extension  Rotation  Abduction  Circumduction

EDU2HBS Human Body Systems 14 Body Movements

EDU2HBS Human Body Systems 15 Special Movements  Dorsifelxion  Plantar flexion  Inversion  Eversion  Supination  Pronation

EDU2HBS Human Body Systems 16 Types of Muscles  Prime mover  Antagonist  Synergist – muscle that aids a prime mover in a movement and helps prevent rotation  Fixator – stabilizes the origin of a prime mover

EDU2HBS Human Body Systems 17 Naming of Skeletal Muscles  Direction of muscle fibers  Relative size of the muscle

EDU2HBS Human Body Systems 18 Naming of Skeletal Muscles  Location of the muscle  Number of origins

EDU2HBS Human Body Systems 19 Naming of Skeletal Muscles  Location of the muscles origin and insertion  Shape of the muscle  Action of the muscle

EDU2HBS Human Body Systems 20 Head and Neck Muscles Figure 6.14

EDU2HBS Human Body Systems 21 Trunk Muscles Figure 6.15

EDU2HBS Human Body Systems 22 Deep Trunk and Arm Muscles

EDU2HBS Human Body Systems 23 Muscles of the Pelvis, Hip, and Thigh

EDU2HBS Human Body Systems 24 Muscles of the Lower Leg

EDU2HBS Human Body Systems 25 Superficial Muscles: Anterior

EDU2HBS Human Body Systems 26 Superficial Muscles: Posterior Figure 6.21