The muscular system

Masseter

Action: Elevates mandible

Synergist: Temporalis

Antagonist: Digastric

Temporalis

Action: Elevates mandible

Synergist: Masseter

Antagonist: Digastric

Digastric

Action: Depress/lower mandible

Synergist:

Antagonist: Masseter

Sternohyoid

Action: Depress/lower hyoid

Synergist: Thyrohyoid

Antagonist:

Sternothyroid

Action: Depress thyroid cartilage (larynx)

Synergist:

Antagonist:

Thyrohyoid

Action: depresses hyoid bone

Synergist: Sternohyoid

Antagonist:

Sternocleidomastoid

Action: Flexes or rotates the head

Synergist:

Antagonist:

Clavo-trapezius

Action: elevates clavicle

Synergist:

Antagonist:

Acromio-trapezius

Action: Adducts scapula

Synergist: Rhomboideus

Antagonist:

Spino-trapezius

Action: Depresses scapula

Synergist: Pectoralis minor

Antagonist: Levator scapulae

Pectoralis minor

Action: depresses scapula

Synergist: Pectoralis minor

Antagonist: Levator scapulae

Levator scapulae

Action: Elevates scapula

Synergist:

Antagonist: spino-trapezius

Serratus anterior

Action: Anterior rotation of scapula

Synergist:

Antagonist:

Rhomboideus

Action: Adducts scapula

Synergist: Acromio-trapezius

Antagonist:

Pectoralis major

Action: adducts humerus

Synergist: Clavo-deltoid

Antagonist: Acromio-deltoid

Clavo-deltoid

Action: adducts humerus

Synergist: Pectoralis major

Antagonist: Supraspinatus

Acromio-deltoid

Action: Abducts humerus

Synergist: Supraspinatus

Antagonist: Latissimus dorsi

Spino-deltoid

Action: Extends humerus

Synergist:

Antagonist:

Infraspinatus

Action: Lateral rotation of humerus

Synergist:

Antagonist: subscapularis

Supraspinatus

Action: Abducts humerus

Synergist: Acromio-deltoid

Antagonist: Latissimus dorsi

Subscapularis

Action: Medial rotation of humerus

Synergist: Teres major

Antagonist: Infraspinatus

Latissimus dorsi

Action: Adducts humerus

Synergist: Clavo-deltoid

Antagonist: Acromio-deltoid

Teres major

Action: Medial rotation of humerus

Synergist: Subscapularis

Antagonist: Infraspinatus

Triceps brachia (medial & lateral)

Action: Extends forearm

Synergist:

Antagonist: Biceps brachii

Biceps brachii

Action: Flexes forearm

Synergist: Brachialis

Antagonist: Triceps brachii