weeeeeeeeeeeeeeeeeeeeeeeeeeeow-
what is the origin
end of muscle connected to unmovable bone
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what is the insertion
bone that will move under contraction
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what is a tendon?
fibrous CT that connects muscle to bone or muscle to muscle
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what is aponeurosis
thin sheet-like tendon
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what is the agonist?
muscle that provides the majority of force in a movement
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what is the antagonist?
must be relaxed or extended when the agonist is active
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what is a synergist?
muscle that assists the agonist
-it can add power to the action
-stabilizes or immobilizes the origin
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what is a fixator?
-stabilizes or immobilizes the origin
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transversus abdominis
Origin:
-lumbar fascia
-inguinal ligament
-cartilages of last six ribs
-iliac crest
Insertion:
-linea alba
-pubic crest
Action:
compresses abdominal contents
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Internal Oblique
Origin:
-lumbar fascia
-inguinal ligament
-iliac crest
Insertion :
-pubic crest
-costal margin
-linea alba
-last three or four ribs
Action:
-Flex vertebral column and compress abdominal wall when pair contracts simultaneously
-individually, aid muscles of back in trunk rotation and lateral flexion
-used in oblique curls
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External Oblique
Origin:
-fleshy strips from outer surfaces of lower eight ribs
Insertion:
-most fibers insert into linea alba via a broad aponeurosis
-some insert into pubic crest and tubercle and iliac crest
Action:
-Flex vertebral column and compress abdominal wall when pair contracts simultaneously
-individually, aid muscles of back in trunk rotation and lateral flexion
-used in oblique curls
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Rectus Abdominis
Origin:
-pubic crest
-symphysis
Insertion:
-xiphoid process
-costal cartilages of ribs 5-7
Action:
-Flex and rotate lumbar region of vertebral column
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Pectoralis Major
Origin:
-cartilage of ribs 1-6 (or 7)
-aponeurosis of external oblique muscle
-sternal end of clavicle
-sternum
Insertion:
-fibers converge into a short tendon that inserts into the intertubercular sulcus of humerus
-greater tubercle of humerus
Action:
-Adducts and medially rotates arm against resistance
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Pectoralis Minor
Origin:
anterior surfaces of ribs 3-5
Insertion:
coracoid process of scapula
Action:
-With ribs fixed, pulls scapula forward and downward
-With scapula fixed, pulls ribcage superiorly
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external intercostals
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internal intercostals
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diaphragm
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frontal belly of epicranius
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orbicularis oris
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orbicularis oculi
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zygomaticus
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masseter
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temporalis
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Sternocleidomastoid
Origin:
-manubrium of sternum
-medial portion of clavicle
Insertion:
-mastoid process of temporal bone
-superior nuchal line of occipital bone
Action:
Flexes and laterally rotates the head;
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anterior scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2
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middle scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2
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posterior scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2
