Shoulder and Axilla Flashcards
The extrinsic shoulder muscles are the ones that have attachments to the thoracic wall and are also called..
thoracoappendicular
The anterior group of extrinsic shoulder muscles are (4)
pec major, minor, subclavius and serratus anterior
The posterior group of extrinsic shoulder muscles are (4)
superficial trap and lat, deep levator scapulae and rhomboids
The 6 intrinsic shoulder muscles are called… and they attach only to shoulder bones.
scapulohumeral
The 6 intrinsic shoulder muscles are…
delt, teres major, and 4 rotator cuff muscles
Origin of the pec major? Insertion?
O: clavicular head, sternocostal head and costal head
I:lateral lip of intertubercular groove of humerus
The pec major forms most of the anterior wall of the …
axilla
The pec major’s inferior border forms the …
anterior axillary fold
The pec major also helps form the …
deltopectoral triangle
What vein runs through the deltopectoral triangle?
cephalic
What are the actions of the pec major?
adducts, medially rotates humerus
flexes and adducts the humerus
Origin of pec minor? Insertion?
O: coracoid process of scapula
I: ribs 3,4,5
What does the pec minor do?
fixes the scapula to the thoracic wall and stretches the arm forward and upward. It helps with inspiration
Serratus anterior forms…
medial wall of axilla
What does the serratus anterior do?
rotates the inferior angle of scapula as well as hold the medial scapula against the thoracic wall
Origin of the serratus anterior? Insertion?
O: ribs 2-9 external lateral surface
I: medial border of scapula
Serratus anterior is innervated by what nerve?
long thoracic
What causes paralysis of the serratus anterior?
injury to the long thoracic nerve
What appearance does paralysis of the serratus anterior give?
medial winged scapula
Trapezius is innervated by
CN XI spinal accessory nerve
Origin of trap? Insertion?
O: superior nuchal line
I: lateral clavicle, acromion, spine of scapula
What causes lateral winged scapula?
damage to the spinal accessory nerve
When is middle subscapular nerve damaged?
during radial breast dissections
What is another name for thoracodorsal nerve?
middle subscapular nerve
Origin of levator scapulae?
Insertion?
O: transverse process of C1-C4
I: medial border superior part of scapula
Levator is innervated by?
dorsal scapular nerve
Rhomboid muscles are innervated by…
dorsal scapular nerve
The deltoid muscle cannot…
initiate the first 15 degrees of abduction
What does the delt do?
stabilizes shoulder joint, flexes and extenses the shoulder. After the initial 15 degrees it abducts the shoulder.
What nerve innervates the delt?
axillary nerve
What type of muscle fiber growth region allows greater force generation?
pinnate
Axillary nerve damage causes:
shoulder joint dislocation and humeral surgical neck fracture
First 15 degrees of shoulder abduction is done by..
supraspinatus muscle
How to test axillary nerve damage?
test deltoid function by abduction
What does Teres major do?
medially rotates and adducts glenohumeral joint
Origin of teres major? Insertion?
O: inferior angle of scapula
I: medial lip of intertubercular groove
What exits out of the quadrangular space?
posterior circumflex of humeral artery and axillary nerve
Rotator cuff muscles:
SItS Supraspinatus Infraspinatus teres minor Subscapularis
What does the supraspinatus do?
abduct the arm
What does subscapularis, and teres minor do?
adducts the arm
What does subscapularis and teres major do?
internally rotates the arm
What does infraspinatus and teres minor do?
externally rotates the arm
Infraspinatus and teres minor are what kind of rotators of the shoulder/humerus?
lateral
How do you test the subscapularis muscle?
lift off or Gerbers test
What other muscle is the Gerber’s lift off test used for?
rhomboid
How do you test supraspinatus integrity?
Jobe’s test or “Empty Can Test”
What is the most compromised muscle of the rotator cuff?
supraspinatus
What muscle is responsible for the first 15 degrees of abduction in the shoulder?
supraspinatus
6 axillary arteries
superior thoracic thoracoacromial lateral thoracic subscapular anterior circumflex posterior circumflex
First part of the axillary artery has one branch
the superior thoracic
Second part of the axillary artery has two branches
thoracoacromial
lateral thoracic
Third part of the axillary artery has three branches
subscapular
anterior and posterior humeral circumflex
The lateral thoracic artery is an important source of blood to …
lateral part of the mammary gland in women
Lateral thoracic artery runs with … to serratus anterior muscle.
lateral
Largest branch of axillary artery…. divides into … and….
subscapular
circumflex scapular
throacodorsal
Circumflex artery supplies blood to ….
thoracodorsal supplies blood to…
subscapularis and teres major
serratus anterior and latissimus dorsi
Two humeral arteries
anterior and posterior circumflex
Where does compression of the axillary artery occur?
1st rib
Axillary vein receives blood fro mthe …
thoracoepigastric vein
Axillary lymph nodes
apical group central group humeral group pectoral group subscapular group
