Chapter 10: The Muscular System
Muscle Functions
Muscle functions include:
● Movement
● Stability
● Control of openings
● Heat production
● Glycemic control
Structural and functional organization of muscles
● Muscles are pieces of soft tissue that are located throughout the body and they help you
do many things, such as e ercises, strenuous work. They also function to move and
support your organs. For e ample, our heart is a hard working muscle that helps with
beating to keep us alive.
● About 600 human skeletal muscles
● Constitute about half of our body weight
● three kinds of muscle tissue:
1. Skeletal
2. Cardiac
3. Smooth
● Specialized for one major purpose:
○ Converting the chemical energy in ATP into the mechanical energy of motion
● Myology = study of the muscular system
Muscle Connective Tissues, Fascicles, and
Compartments
Endomysium
● Thin sleeve of loose connective tissue around each fiber
● Provides chemical environment for muscle fiber
● ENDO = inner most
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Perimysium
● Thicker layer of connective tissue that wraps
fascicles
● Carries nerves, blood vessels, and stretch
receptors
● Middle layer = thicker layer
Epimysium
● Fibrous sheath surrounding entire muscle
● Allows the muscles to contract and move
powerfully while maintaining structural
integrity
● EPI = outer
Functional Groups of muscles
Prime mover (agonist)
● Muscle producing most of force during a particular action
● E : Lift a glass of water oI a table, the agonist is the bicep muscle.
Synergist
● Muscle that aids the prime mover (agonist)
○ May contribute additional force, modify the direction of movement, or stabilize
a nearby joint
○ Not responsible for prime movement but contributes to movement
Antagonist
● Muscle that opposes the action of the prime mover = undo what agonist has done
○ Contracts to prevent e cessive movement or rela es to give prime mover
control over an action
○ Antagonistic pairs– muscles that act on opposite sides of a joint
○ E : triceps is the antagonist muscle
Fi ator
● Muscle that prevents movement of bone
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○ Provide stable base for movement