Download Muscles - Palomar College

Muscular System
• Functions
•Voluntary movement
• Forms some sphincters
• Protection of some organs
• Stabilization of some joints
• Posture
• Heat production
Muscular System
• Organs
– Muscles
Muscular System
• Organs
– Muscles (includes tendons
and aponeuroses)
• Structure of Skeletal Muscles
– Muscle fibers
• Structure of Skeletal Muscles
– Muscle fibers
• Structure of Skeletal Muscles
– Muscle fibers
• Contractile units within:
• Structure of Skeletal Muscles
– Muscle fibers
• Contractile units within:
– Sarcomeres
• Structure of Skeletal Muscles
– Muscle fibers
• Contractile units within:
– Sarcomeres
• Structure of Skeletal Muscles
– Muscle fibers
• Contractile units within:
– Sarcomeres
– Sarcomeres linked end-to
end
• Structure of Skeletal Muscles
– Muscle fibers
• Contractile units within:
– Sarcomeres
– Sarcomeres linked end-to
end; form myofibrils
• Muscle fibers bundled into
fascicles
• Muscle fibers bundled into
fascicles
• Fascicles bundled to form the
muscle
• Connective Tissue in Muscle
• Connective Tissue in Muscle
– Endomysium
• Connective Tissue in Muscle
– Endomysium
– Perimysium
• Connective Tissue in Muscle
– Endomysium
– Perimysium
– Epimysium
• How Muscles Create Movement at
Joints
– Muscles must cross joints
– Insertion pulled towards origin
Fascicle Organization
• Parallel
– Greatest
range of
motion
Fascicle Organization
• Parallel
• Pennate
Fascicle Organization
• Parallel
• Pennate
– Strongest
force of
contraction
Fascicle Organization
• Parallel
• Pennate
• Convergent
•
Fascicle Organization
• Parallel
• Pennate
• Convergent
– Greatest
versatility
•
Fascicle Organization
• Parallel
• Pennate
• Convergent
• Circular
Muscle-Bone Lever Systems
Muscle-Bone Lever Systems
F
Muscle-Bone Lever Systems
F
Muscle-Bone Lever Systems
R
F
Muscle-Bone Lever Systems
E
R
F
Third-class lever
Muscle-Bone Lever Systems
E
R
F
Third-class lever
E
R
F
Third-class lever
E
R
F
Third-class lever
E
R
F
Third-class lever
Amplifies
speed and
distance at the
expense of
force
E
R
F
Third-class lever
Muscle-Bone Lever Systems
E
R
F
Third-class lever
Muscle-Bone Lever Systems
E
R
F
Third-class lever
Muscle-Bone Lever Systems
E
R
F
Third-class lever
Muscle-Bone Lever Systems
E
R
F
Second-class lever
Muscle-Bone Lever Systems
E
R
F
First-class lever
Muscle Interaction
• Prime Mover
– Muscle most responsible for
an action
• e.g.: abduction of arm:
deltoid
Muscle Interaction
• Synergistic muscles
– Assists prime mover
• e.g.: supraspinatus assists
deltoid in abduction
Muscle Interaction
• Fixator muscles
– Holds bone of origin steady
• e.g.: serratus anterior holds
deltoid’s bone of origin
steady during abduction
Muscle Interaction
• Antagonistic muscles
– Action opposite that of the
prime mover
• e.g.: lats and pects adduct
• must not contract during
abduction
• Muscle names may indicate the
direction of the muscle fibers
(e.g., transversus abdominis,
external oblique).
• Muscle names may indicate the
direction of the muscle fibers (e.g.,
transversus abdominis, external
oblique).
• A muscle may be named according
to its location (e.g., temporalis,
tibialis anterior).
• The size of the muscle may be
indicated in the name (e.g.,
gluteus maximus, adductor
Iongus).
• Some muscles are named on the
basis of shape (e.g., deltoid,
serratus anterior).
• Muscles may be named after their
origin and insertion (e.g.,
sternocleidomastoid).
• A muscle may be named according
to its location (e.g., temporalis,
tibialis anterior).
• Muscles may be named for their
number of origins (e.g., triceps
brachii, quadriceps femoris).
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