Question | Answer |
Pectoralis Major | Origin-Medial half of clavicle, sternum, and upper 6-7 costal cart
Insertion-Later lip of intertubercular groove, humerus
Action-Adduct, medially rotate and flex the arm
nerves:Later and medial pectoral nerve from brachial plexus |
deltopectoral groove | holds the cephalic vein (a superficial vein with no accompanying artery) |
Pectoralis minor | Origin: 3rd, 4th, 5th ribs close to junction of costal cart
Insertion: coracoid process of scapula
Action: depress shoulder, protraction of scapula
nerves:lateral and medial pectoral nerve from brachial plexus |
subclavius | origin: first rib
insertion:subclavian groove on inferior side of clavicle
action:stabilize clavicle and protect axillary vessels |
serratus anterior | origin:lateral, external surface of ribs 1-8
Insertion:medical border of scapula
action:hold and rotate scapula against thoracic wall. protracts
nerves:long thoracic nerve from brachial plexus |
long Thoracic nerve | innervates serratus anterior muscle on superficial side (injury results in winged scapula) |
Trapezius | Origin: Medial 1/3 of superior nuchal line, eop, nuchal ligament, spinal processes of C7-T12
Insertion: lateral 1/3 of clavicle, acromion and spine of scapula
Main actions:elevates, depresses, and retracts scapula
Nerve:cranial nerve XI (spinal accesso |
Latissimus dorsi | Origin: Spinous process of T6-T12, thoracolumbar fascia, iliac crest, and inf 3-4 ribs
Insertion: Floor of intertubercular sulcus of humerus
Action: extends, adducts, and medially rotates humerus
Nerve: Thoracodorsal |
Levator Scapulae | Origin:Transverse processes of C1-C4
Insertion:Medial border of scapular superior to root of spine
action:elevates scapula and slightly rotates
nerve:dorsal scapular and C3/C4 cervical |
Rhomboid major/minor | Origin: Ma=spinous process of T2-T5 Mi=nuchal ligament/spinous process of C7/T1
Insertion: Ma=medical border of scapula Mi=medical end of scapular spine
action: retract scapula and rotate (and fix to wall)
Nerve: dorsal scapular |
serratus posterior superior | origin: nuchal ligament/spinous process of C7-T3
Insertion: superior borders of ribs 2-4
Action: elevates ribs
nerve: 2-5th intercostal nerves |
serratus posterior inferior | origin:spinous processes of T11-L2
Insertion:inferior border of ribs 8-12
action:depress ribs
nerve:9th-12th intercostal nerves |
Splenius | Origin:Nuchal ligament and spinous processes of upper thoracic vert
insertion:occipital bone and trans processes of upper cervical vert
action:Flexes and rotates head and neck/extends head and neck
nerve:posterior primary rami of cervical spinal nerves |
erector spinae (illiocostalis, longissimus, spinalis) | Origin:arises by broad tendon from iliac crest
insertion: I=rib and cervical trans proc L=ribs and trans proc in thor/cerv and cranium S=spin proc of upper thor
Action:extend vertebral column and head/laterally flex
nerve:posterior rami of spinal nerve |
semispinalis | Origin:transverse process of C4-T10
Insertion:spinous processes of vertebrae 4-6 and cranium
action:extends and rotates head and vert column
Nerve:post rami of spinal nerve |
Multifidus | Origin:sacrum, illium, trans processes
insertion:spinous processes of vert 2-4
action: contralateral rotation
nerve: posterior rami of spinal nerve |
rotatores: | origin:transverse processes
insertion: spinour process of vert
action:stabilizes vert
nerve:posterior rami of spinal nerves |