Memmler’s A&P
Chap 8
The muscular system
Functions of muscular system p161
• Movement of skeleton
• Maintenance of posture
• Generation of heat
Types of muscle p160
Structure of muscle p161
p 162 Table 8-2
1. Endomysium
2. Perimysium
3. Epimysium
Neuron
Neuromuscular junction
(NMJ) p162
•Acetylcholine: neurotransmitter
that works at the NMJ
•Muscle fibers have the property
of excitability.
•The nerve impulse is an electrical
current that is called an action
potential.
Contraction of muscle p162
• Contractility
• Role of calcium in muscle contraction
• When a muscle cell is stimulated, contraction
is always the result.
Energy sources p 165
• Energy sources for muscle contraction
– ATP
– Myoglobin
– Glycogen
– Creatine phosphate
Oxygen consumption p165-166
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Aerobic function
Anaerobic function
Lactic acid
Oxygen debt
Effects of exercise on muscle p166
• Increase in capillaries
• Increase in mitochondria
• Increase in reserves of myoglobin, glycogen,
creatine phosphate
• Prevent muscle atrophy and contractures
Types of muscle contractions p167
• Isotonic contraction: produces movement.
Ex: walking, lifting weights, running
• Isometric contraction: increase in muscle
tension. Ex: Pushing against an immovable
object
• Most body movements are a combination of
both isotonic and isometric contractions.
Movement p167
•Origin
•Insertion
•Muscles work together to
accomplish skeletal
movement.
•Prime mover
•Antagonist
Anterior muscles
p170
•Deltoid
•Quadriceps femoris
•Vastus lateralis
(p178)
Posterior muscles
p171
•Deltoid
•Gluteus maximus and
gluteus medius
•Gastrocnemius
•Notice the Achilles
tendon
•Most common injury
in nurses is lumbar
muscle strain p175
Muscles of respiration p175
Muscular disorders 179
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•
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•
Spasm
Strain
Sprain
Atrophy
Muscular diseases 179-180
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•
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Myalgia
Myositis
Bursitis
Tendinitis
Shinsplints
Carpal tunnel syndrome