TBL13 Flashcards
Pectoral muscles are derivatives of what?
parietal mesoderm
Pectoralis major attachments
sternocostal and clavicular heads of the pectoralis major attach to the sternum, superior six costal cartilages, and clavicle proximally and to the humerus distally
Pectoralis major function
simultaneous contraction of the two heads adducts the upper extremity and medially rotates the arm at the glenohumeral joint
Serratus anterior attachments
attaches to lateral portions of the 1st to 8th ribs proximally and to the medial border of the scapula distally
Serratus anterior function
protracts the scapula when reaching for something and recall the trapezius and rhomboids retract the protracted scapula
Pectoralis minor attachments
deep to the pectoralis major, attaches to the 3rd to 5th ribs proximally and to the coracoid process of the scapula distally
Pectoralis minor function
pectoralis minor stabilizes the scapula against the posterior thoracic wall during protraction
Serratus anterior with the superior and inferior parts of the trapezius synergistically?
rotate the scapula upward allowing the deltoid to fully abduct the upper extremity from the horizontal plane
Lateral pectoral nerve
innervates the clavicular head of the pectoralis major
Medial pectoral nerve
innervates both the sternocostal head and the pectoralis minor
Long thoracic nerve
innervates the serratus anterior
Which muscles are absent or partially lost in the Poland sequence defect?
absence of the pectoralis minor and partial loss of the pectoralis major (usually the sternal head) -> nipple and areola are absent of displaced, fused digits, short digits
Why is the long thoracic nerve vulnerable to injury and how are abduction and rotation at the glenohumeral joint hindered after its injury? How does the winged scapula deformation occur?
the long thoracic nerve courses on the superficial aspect of the serratus anterior; after injury, the medial border of the scapula moves laterally and posteriorly away from the thoracic wall -> winged scapula
Deep fascia
sheet of dense connective tissue named by the tissue it covers
Pectoral fascia
fascia leaves the lateral border of the pectoralis major to become the axillary fascia, which surrounds the neurovascular contents of the axilla
Boundaries of the axilla
subscapularis, serratus anterior, and pectoralis major form the posterior, medial, and anterior boundaries, respectively
Axilla connects what to where?
determine nerves and blood vessels pass from the root of the neck through the axilla into the upper extremity
Axillary artery
continues from the subclavian artery at the lateral border of the first rib and envision its proximal branches (ignore names) supply the pectoralis major and minor and the serratus anterior
Blood supply of the deltoids
posterior circumflex humeral and anterior circumflex humeral arteries arise from the axillary artery and anastomose around the humerus to supply the deltoid
Subscapular artery
arises from the axillary artery, is a very short artery, then divides into the thoracodorsal artery (latissimus dorsi) and the circumflex scapular artery (teres major and minor)
Circumflex scapular artery
supplies the teres major and minor, anastomoses on the posterior surface of the scapula with the suprascapular artery, a branch of the subclavian artery that supplies the supraspinatus and infraspinatus
Dorsal scapular artery
another branch of the subclavian artery, supplies the levator scapulae and rhomboids and contributes to the anastomoses on the posterior scapula
Brachial artery
axillary artery continues as the brachial artery at the inferior border of the teres major
Where can the axillary artery be ligated without stopping blood flow into the ipsilateral upper extremity?
ligated between the 1st rib and subscapular artery; subclavian to suprascapular artery to circumflex scapular artery bypasses
Axillary vein
receives venous tributaries corresponding to branches of the axillary artery
Lymphatic vessels of the upper extremity
accompany the axillary vein tributaries and drain into the axillary lymph nodes
Efferent lymph vessels from the axillary nodes drain into?
drain into the supraclavicular nodes
Efferent lymph vessels from the supraclavicular lymph nodes drain into?
drain into the veins in the root of the neck
Which two nerves are at risk during surgical removal of pathologic axillary nodes? Why can removal result in lymphedema?
Long thoracic nerve and thoracodorsal nerve; removal of LNs result in lymphedema because lymphatic drainage is impeded
What comprise the roots of the brachial plexus?
anterior rami of spinal nerves C5-T1
Organization of brachial plexus starting from closest to vertebral column?
root, trunk, division, cord, branches
“Run To Drink Cold Beer”