Download 10-03_pptlect

Anatomy & Physiology
SIXTH EDITION
Chapter 10, part 3
Muscle Tissue
PowerPoint® Lecture Slide Presentation prepared by
Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Frederic H. Martini
Fundamentals of
Tension production by skeletal muscles
• Internal tension generated inside contracting
muscle fibers
• External tension generated in extracellular fibers
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.16 Internal and External Tension
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.16
• Motor units
• All the muscle fibers innervated by one neuron
• Precise control of movement determined by
number and size of motor unit
• Muscle tone
• Stabilizes bones and joints
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.17 The Arrangement of Motor Units in
a Skeletal Muscle
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.17
Contractions
• Isometric
• Tension rises, length of muscle remains constant
• Isotonic
• Tension rises, length of muscle changes
• Resistance and speed of contraction inversely
related
• Return to resting lengths due to elastic
components, contraction of opposing muscle
groups, gravity
PLAY
Animation: Whole Muscle Contraction
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.18 Isotonic and Isometric Contractions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.18
Figure 10.19 Resistance and Speed of
Contraction
PLAY
Animation: Skeletal muscle contraction
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.19
SECTION 10-5
Energy Use and Muscle Contraction
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Muscle Contraction requires large amounts of
energy
• Creatine phosphate releases stored energy to
convert ADP to ATP
• Aerobic metabolism provides most ATP needed
for contraction
• At peak activity, anaerobic glycolysis needed to
generate ATP
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.20 Muscle Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.20
Figure 10.20 Muscle Metabolism
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.20
Energy use and level of muscular activity
• Energy production and use patterns mirror
muscle activity
• Fatigued muscle no longer contracts
• Build up of lactic acid
• Exhaustion of energy resources
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Recovery period
• Begins immediately after activity ends
• Oxygen debt (excess post-exercise oxygen
consumption)
• Amount of oxygen required during resting
period to restore muscle to normal conditions
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
SECTION 10-6
Muscle Performance
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Types of skeletal muscle fibers
• Fast fibers
• Slow fibers
• Intermediate fibers
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.21 Fast versus Slow Fibers
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.21
Fast fibers
• Large in diameter
• Contain densely packed myofibrils
• Large glycogen reserves
• Relatively few mitochondria
• Produce rapid, powerful contractions of short
duration
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Slow fibers
• Half the diameter of fast fibers
• Take three times as long to contract after
stimulation
• Abundant mitochondria
• Extensive capillary supply
• High concentrations of myoglobin
• Can contract for long periods of time
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Intermediate fibers
• Similar to fast fibers
• Greater resistance to fatigue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Muscle performance and the distribution of
muscle fibers
• Pale muscles dominated by fast fibers are called
white muscles
• Dark muscles dominated by slow fibers and
myoglobin are called red muscles
• Training can lead to hypertrophy of stimulated
muscle
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Physical conditioning
• Anaerobic endurance
• Time over which muscular contractions are
sustained by glycolysis and ATP/CP reserves
• Aerobic endurance
• Time over which muscle can continue to
contract while supported by mitochondrial
activities
PLAY
Animation: Muscle fatigue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
SECTION 10-7
Cardiac Muscle Tissue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Structural characteristics of cardiac muscle
• Located only in heart
• Cardiac muscle cells are small
• One centrally located nucleus
• Short broad T-tubules
• Dependent on aerobic metabolism
• Intercalated discs where membranes contact one
another
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.22 Cardiac Muscle Tissue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.22
Functional characteristics of cardiac muscle
tissue
• Automaticity
• Contractions last longer than skeletal muscle
• Do not exhibit wave summation
• No tetanic contractions possible
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
SECTION 10-8
Smooth Muscle Tissue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Structural characteristics of smooth muscle
• Nonstriated
• Lack sarcomeres
• Thin filaments anchored to dense bodies
• Involuntary
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.23 Smooth Muscle Tissue
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 10.23
Functional characteristics of smooth muscle
• Contract when calcium ions interact with
calmodulin
• Activates myosin light chain kinase
• Functions over a wide range of lengths
• Plasticity
• Multi-unit smooth muscle cells are innervated by
more than one motor neuron
• Visceral smooth muscle cells are not always
innervated by motor neurons
• Neurons that innervate smooth muscle are not
under voluntary control
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
You should now be familiar with:
• The organization of muscle and the unique
characteristics of skeletal muscle cells.
• The structural components of the sarcomere.
• The events at the neuromuscular junction.
• The key concepts involved in skeletal muscle
contraction and tension production.
• How muscle fibers obtain energy for contraction.
• Aerobic and anaerobic contraction, muscle fiber
types, and muscle performance.
• The differences between skeletal, cardiac and
smooth muscle
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings