Muscles of Upper Limb Flashcards
Pectoralis Major
O: anterior/medial clavicle, sternum, superior 6 costal cartilages, external oblique aponeurosis
I: Intertubercular groove of humerous
A: ADduction & medial rotate arm
Clavicular portion flexus humerous
Sternocostal portion extends from flexed position
N: medial and lateral pectoral nerve (mostly lateral)
B: Pectoral branch of thoracoacromial trunk
Pectoralis Minor
O: Ribs 3-5 near costal cartilage
I: Medial/Superior coracoid process of scapula
A: stabilizes scapula against thoracic cage, elevates ribs when scapula is fixed (accessory m. of resp)
N: medial pectoral nerve (some contribution from lateral)
B: Thoracoacromial trunk (pectoral branch)
Subclavius
O: junction of 1st rib and manubrium
I: inferior center of the clavicle
A: anchors and depresses the clavicle
N: Nerve to the subclavius
Serratus Anterior
O: Lateral parts of ribs 1-8
I: medial/anterior border of scapula
A: protracts/stabilizes scapula, lower fibers rotate scapula
Main muscle that holds scapula down onto ribcage
N: Long Thoracic Nerve
Note: most motor nerves to muscles pass deep to them. The long thoracic nerve to serratus anterior is superficial!
Damage to what nerve/muscle results in a winged scapula?
Damage to The Long Thoracic Nerve - innervates Serratus Anterior. Have pt push against wall, serratus anterior can’t hold scapula back so it pops up. Pt can’t abduct arm above 90 degrees.
Trapezius
O: occiput, spinous processes of C1-T12
I: Lateral 1/3 of clavicle, acromion, superior border of scapular spine
A: elevates, retracts, rotates, depresses scapula
N: CN XI (accessory nerve)
Levator Scapulae
O: Transverse Processes C1-C4
I: superior angle of scapula
A: elevates scapula
N: dorsal scapular nerve
Rhomboid Minor
O: spinous processes C6-7
I: medial border of scapula above scapular spine
A: retracts and elevates scapula
N: dorsal scapular nerve
Rhomboid Major
O: spinous processes T1-4
I: medial border of scapula below scapular line
A: retracts and elevates scapula
N: dorsal scapular nerve
Latissimus Dorsi
O: spinous processes T7-12, thoracolumbar fascia, iliac crest
I: floor of intertubercular groove of huerous
A: ADduct, extend, medially rotate humerous
“pull-up muscle”
N: thoracodorsal nerve
Deltoid
O: lateral third of clavicle, acromion, and scapular spine
I: deltoid tuberosity of humerus
A: anterior part flexes & medially rotates arm, middle part abducts the arm, posterior part extends & laterally rotates arm
N: axillary nerve
Teres Major
O: posterior surface of inferior angle of scapula
I: medial lip of the intertubercular groove of humerus
A: adduction and medial rotation of arm (mini lat dorsi)
N: lower subscapular nerve
Part of Rotator Cuff
Which muscles make up the rotator cuff?
“SITS”
Supraspinatous: suprascapular nerve
Infraspinatous: suprascapular nerve
Teres Minor: axillary nerve
Subscapularis: upper & lower subscapular nerve
Supraspinatous
O: supraspinous fossa of scapula
I: superior aspect of the greater tubercle of the humerus
A: initiates abduction, stabilization of glenohumeral-jt
N: suprascapular nerve
Infraspinatous
O: infraspinatus fossa of the scapula
I: greater tubercle of the humerus
A: lateral rotation, stabilizatoin of glenohumeral-jt
N: suprascapular nerve