what is the origin
end of muscle connected to unmovable bone
what is the insertion
bone that will move under contraction
what is a tendon?
fibrous CT that connects muscle to bone or muscle to muscle
what is aponeurosis
thin sheet-like tendon
what is the agonist?
muscle that provides the majority of force in a movement
what is the antagonist?
must be relaxed or extended when the agonist is active
what is a synergist?
muscle that assists the agonist
-it can add power to the action
-stabilizes or immobilizes the origin
what is a fixator?
-stabilizes or immobilizes the origin
transversus abdominis
Origin:
-lumbar fascia
-inguinal ligament
-cartilages of last six ribs
-iliac crest
Insertion:
-linea alba
-pubic crest
Action:
compresses abdominal contents
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
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
Rectus Abdominis
Origin:
-pubic crest
-symphysis
Insertion:
-xiphoid process
-costal cartilages of ribs 5-7
Action:
-Flex and rotate lumbar region of vertebral column
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
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
external intercostals
internal intercostals
diaphragm
frontal belly of epicranius
orbicularis oris
orbicularis oculi
zygomaticus
masseter
temporalis
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;
anterior scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2
middle scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2
posterior scalene
origin: transverse processes of cervical vertebrae
insertion: anterolaterally on ribs 1-2
action: elevate ribs 1-2