Download Muscles of head, neck and torso

Muscles
Head, Neck and Torso
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Over 600 Muscles
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Muscles
• 2 separate groups: for every bone, there’s a
muscle on the back of the bone and a muscle
on the front
– Frontal muscles: in general function is to flex,
flexor muscles
– Back: in general  exstensors (of arm or leg)
• Flex: joint angle decreasing
• Extend: straightening
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Muscles are Named By:
• Direction of muscle fibers:
– Rectus - straight
– Transverse – horizontal
– Oblique – diagonally
• Location:
– Pectoralis – chest
– Frontalis – over the frontal
bone
• Shape:
– Serratus – saw toothed
– Deltoid – triangular
• # of origins:
– Biceps
– Triceps
• Action
– Adductor
– Flexor – extensor
– Supinator –
pronator
• Origin and insertion
– Sternocleidomastoid
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Muscles of Facial Expressions
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Muscles that Move the Head
• Sternocleidomastoid
– Depresses(flexes neck),
rotates head
• Scalenes
– Anterior, middle and
posterior
– Help turn head side to
side
– Lifts the first 2 ribs to
assist inspiration
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Anterior Abdominal
• Rectus Abdominis
– “six pack”
– Flexes
spine/torso
– Stabilizes body
• External Oblique
– Rotation of torso
– Stabilize
• Internal Oblique
– Same as above
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Anterior Abdominal
• Diaphragm
– Main muscle in
inspiration
– Separates
abdomen from
thorax
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Intercostal Muscles
• Internal Intercostals
– Forced Expiration
• External Intercostals
– Aid in inspiration
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Muscles that Move the
Shoulder Girdle (anterior)
• Pectoralis major
– Prime mover in
shoulder flexion,
flexes, adducts
arm medially
• Pectoralis minor
– Pulls scapula
forward
(anteriorly) and
downward
• Serratus Anterior
– Rotates scapula
upward & laterally
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Muscles that Move the
Shoulder Girlde (posterior)
• Trapezius:
– Extends head, shrugs
shoulder
– Adducts scapulae
• Levator Scapulae
– Elevates scapula
• Rhomboid major and
minor
– Pulls scapula inward
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Muscles that Move the Humerus
• Latissimus dorsi
– Arm extension and
adduction
• Pulls arm posteriorly
• Teres Major and Teres
Minor
– Work synergistically
with above (adduction)
• Deltoid
– Shoulder abduction
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