Muscular System
Human Anatomy and Physiology I
Oklahoma City Community College
Dennis Anderson
2
Muscles
• Movement• Posture• Stabilize joints• Generate heat• Protect
6
Dorsiflexion & Plantar Flexion
7
Abduction, Adduction & Circumduction
11
Terminology
• Prime mover (Agonist)– Muscle that is the main force for a given
movement• Biceps—prime mover for elbow flexioin
• Antagonist– Muscle that oppose a given movement
• Triceps
12
Terminology Continued
• Synergist– Muscle that works with another muscle for a
given movement
• Belly– Thickest part of muscle– Biceps belly near the middle of the humerus
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Muscle Attachments
Origin
Insertion
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Origin• Muscle attachment that moves the least
Insertion• Muscle attachment that moves the most
SternocleidomastoideusFlexes and Rotates Head
O: Sternum Manubrium & ClavicleI: Mastoid process
MasseterElevate Mandible
O: Zygomatic ArchI: Mandible
TemporalisElevate & Retract Mandible
18
Orbicularis orisCloses & Protrudes Lips
O: Maxilla & MandibleI: Mouth
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BuccinatorSucking & Whistling
TrapeziusExtend Head, Adduct, Elevate or
Depress Scapula
Trapezius
21
Rhomboid MajorAdduct Scapula
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Teres MajorAdduct Humerus
O: ScapulaI: Humerus
Latissimus DorsiExtend, Adduct & Rotate Arm
Medially
Latissimus
dorsi
O: Vertebrae, Ilium, Ribs, ScapulaI: Humerus
DeltoidAbduct, Flex & Extend Arm
O: Clavicle and ScapulaI: Deltoid Tuberosity of Humerus
SupraspinatusAbduct arm
InfraspinatusRotates Humerus Laterally
Pectoralis MajorFlexes, adducts & rotates arm
medially
O: Clavicle and SternumI: Greater Tubercle of Humerus
Biceps BrachiiFlexes Elbow Joint
O: Coracoid Process & Glenoid Cavity
I: Radial Tuberosity
Triceps BrachiiExtend Elbow Joint
O: Humerus & Scapula
I: Olecranon
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BrachialisFlex forearm
O: Humerus
I: Ulna
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BrachioradialisFlex Forearm
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Flexor Carpi RadialisFlex Wrist
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Flexor Digitorum Superficialis
Flex Fingers
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Pronator TeresPronates forearm
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Supinator
Supinates forearm
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Estensor Carpi Radialis Longus
Extend Wrist
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Estensor Digitorum
Extend Fingers
Rectus AbdominusFlexes Abdomen
O: Pubis
I: Xiphoid Process & Cartilage of Ribs
External ObliqueCompress Abdomen
Internal ObliqueCompress Abdomen
External IntercostalsElevate ribs
Internal IntercostalsDepress ribs
DiaphragmInspiration
Gluteus Maximus
O: Ilium, Sacrum & Coccyx
I: Gluteal Tuberosity
Extends & Rotates Thigh Laterally
Rectus Femoris
O: Ilium
I: Patella & Tibial Tuberosity
Flexes Thigh, Extends Lower Leg
Vastus LateralisExtends Lower Leg
Vastus MedialisExtends Lower Leg
Adductor LongusAdduct, Rotate & Flex Thigh
Laterally
GracilisAdducts and Flexes Thigh
O: Ischium and Pubis
I: Tibia
Sartorius
O: Anterior Superior Iliac Spine
I: Medial Side of Tibia
Flexes Thigh, & Rotates Thigh Laterally
Biceps Femoris
O: Ischial Tuberosity
I: Tibia & Fibula
Extends Thigh & Flexes Lower Leg
SemitendinosusExtends Thigh & Flexes Lower Leg
SemimembranosusExtends Thigh & Flexes Lower Leg
Gastrocnemius
O: Femur
I: Calcaneus of Foot
Plantar Flexes Foot & Flex Lower Leg
SoleusPlantar Flexes Foot
Tibialis AnteriorDorsiflexes and Inverts Foot
O: Lateral Condyle of Tibia
I: Ankle