Download The Muscular System

Muscle of the Thorax and Abdomen
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Determine the anatomical movements
indicated in the diagrams
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Pectoantebrachialis (not in humans)
Pectoralis major
Pectoralis minor
Xiphihumeralis (not in humans)
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NO HUMAN HOMOLOG
Origin:
 manubrium (sternum)
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Insertion:
 fascia of forelimb near elbow
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Action:
 rotates forelimb and draws
limb toward chest (adduction)
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Origin:
 Clavicle, sternum, ribs 1-6
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Insertion:
 Greater tubercle of humerus
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Action:
 rotate forelimb and draw
toward chest (adduction)
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Origin:
 Sternum (xiphoid process)
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Insertion:
 Proximal half of humerus
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Action:
 Rotate forelimb and draw
toward chest (adduction)
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NO HUMAN HOMOLOG
Origin:
 Sternum (xiphoid process)
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Insertion:
 By narrow tendon near
proximal end of humerus
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Action:
 Rotate forelimb and draw
towards chest (adduction)
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Lattisimus dorsi
External obliques
Rectus abdominus
Largest muscle of the back
 Origin:
 Last 6 thoracic vertebrae, all
lumbar vertebrae and iliac crest
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Insertion:
 Intertubercular groove
(humerus)
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Action:
 Pulls forelimb dorsocaudally
Largest muscle of the back
 Origin:
 Last 6 thoracic vertebrae, all
lumbar vertebrae and iliac crest
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Insertion:
 Intertubercular groove
(humerus)
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Action:
 Pulls forelimb dorsocaudally
Paired superficial muscles that
make up the lateral walls of
the abdomen
 Origin:
 Lower ribs
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Insertion:
 Iliac crest
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Action:
 Trunk movement – flexion, ab
compression, lateral rotation
Paired muscles deep to the
external obliques
 Origin:
 Iliac crest
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Insertion:
 Last three ribs
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Action:
 Same as external obliques
Most superficial muscles of
the abdomen; largest muscle
of the abdomen
 Origin:
 pubis
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Insertion:
 Xiphoid process, Rib cage
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Action:
 Flex the vertebral column
Pectoantebrachialis
Pectoralis major
Pectoralis minor
Xiphihumeralis
Lattisimus dorsi
External obliques
Rectus abdominus
Biology corner
Human
Muscles
Pectoralis
Major
Teres Major
Latissimus dorsi
Serratus anterior
External obliques
Biology corner
Human
Muscles
Rectus abdominus
Muscle of the shoulder and upper forelimb
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Trapezius in humans
Region: shoulder
Action: pulls clavicle forward
and upward, draws the
scapula dorsally; allows
forward extension of the
humerus
Antagonists: rotator cuff,
latissimus dorsi, pectoralis
major, subscapularis
Origin:
Insertion:
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Deltoid in Humans
Location: Shoulder
Action: forward extension of
the humerus, flexes the elbos
Antagonists: rotator cuff,
latissimus dorsi, pectoralis
major, subscapularis
Origin:
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Action:
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Insertion:
Muscle of the Shoulder and Forelimb: VENTRAL
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Longus/brevis
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Communis/lateralis
Action:
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Muscle of the Shoulder and Forelimb: DORSAL
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Muscle of the Head and Neck
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Sternomastoid/cleidomastoid
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