Muscular System • Functions •Voluntary movement • Forms some sphincters • Protection of some organs • Stabilization of some joints • Posture • Heat production
Transcript
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
F
Muscle-Bone Lever Systems
F
Muscle-Bone Lever Systems
R
F
Muscle-Bone Lever Systems
R
F
E
Third-class lever
Muscle-Bone Lever Systems
R
F
E
Third-class lever
Muscle-Bone Lever Systems
F
E R
Third-class lever
R
F
E
Third-class lever
F
E R
Third-class lever
F
E R
Third-class lever
Amplifies speed and
distance at the expense of
force
R
F
E
Third-class lever
Muscle-Bone Lever Systems
R
F
E
Third-class lever
Muscle-Bone Lever Systems
R
F
E
Third-class lever
Muscle-Bone Lever Systems
R
F
E
Second-class lever
Muscle-Bone Lever Systems
R
F
E
First-class lever
Muscle-Bone Lever Systems
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).