Shoulder Breast Pec Flashcards
Where is the clavicopectoral fascia?
Deep to pec major (encloses subclavius m. and pectoralis minor m.
What dermatome covers the level of the clavicles?
C5
What dermatome covers the level of the nipples?
T4
What dermatome covers the level of the umbilicus?
T10
What are the mm. of the rotator cuff? What does it do?
SITS: Supraspinatus; Intraspinatus; Teres minor; Subscapularis
-Fixes humeral head in glenoid cavity during arm flexion and abduction
Pectoralis major: innervation and actions?
- medial and lateral pectoral nerves
- flexes arm, adducts arm, rotates arm medially
Pectoralis minor: innervation and actions?
- medial pectoral nerve
- lowers lateral angle of scapula, protracts scapula. elevates ribs if scapula fixed.
Serratus anterior: innervation and actions?
- long thoracic nerve
- protracts and rotates scapula, holds it against T-wall (stabilization)
- Boxer’s muscle
- Supplied by lateral thoracic artery
Deltoid: innervation and actions?
- axillary nerve
- clavicular part: flexes and medially rotates arm
- acromial part: abducts arm beyond initial 10-15 degrees up to 100 degrees (supraspinatus before, trapezius after)
- spinal part: extends and laterally rotates arm
Supraspinatus: innervation and actions?
- suprascapular nerve
- initiates arm abduction (up to 10-15 degrees), acts w/rotator cuff mm. (doesn’t rotate the humerus)
Infraspinatus: innervation and actions?
- suprascapular nerve
- lateral arm rotation (w/teres minor)
Teres minor: innervation and actions?
- axillary nerve
- laterally rotates arm
Subscapularis: innervation and actions?
- upper and lower subscapular nerves
- medially rotates arm, adducts arm, holds humeral head in glenoid cavity
Which m. is most commonly torn in rotator cuff injuries?
Supraspinatus m.
Teres major: innervation and actions?
- lower subscapular nerve
- adducts arm, medially rotates arm
Latissimus dorsi: innervation and actions?
- thoracodorsal nerve
- extends, adducts, and medially rotates humerus at shoulder
- supplied by thoracodorsal artery
Levator scapulae: innervation and actions?
- ventral rami of C3-C4, dorsal scapular nerve
- elevates scapula medially, inferiorly rotates glenoid cavity
Rhomboid major: innervation and actions?
- dorsal scapular nerve
- fixes scapula to T-wall, retract and rotate scapula to depress glenoid cavity (drops shoulder)
Rhomboid minor: innervation and actions?
- dorsal scapular nerve
- fixes scapula to T-wall, retracts and rotates scapula to depress glenoid cavity (drops shoulder)
Arteriole anastomoses about the shoulder: subclavian –> axillary route
Subclavian a. –> suprascapular a. –> circumflex scapular a. –> subscapular a. –> axillary a.
- (suprascapular a. is in thyrocervical trunk of subclavian branch)
- (circumflex scapular a. is branch of subscapular a. from axillary branch)
What is important about the suprascapular notch?
Suprascapular artery and nerve: army over, navy under (the ligament)
Quadrandular space: what makes up its borders? What lies w/in it?
- teres minor, teres major, long head of triceps, humerus
- axillary n. + posterior humeral circumflex a.
Triangular space: what makes up its borders? What lies w/in it?
- teres minor, teres major, long head of triceps
- circumflex scapular a.
Triangular interval: what makes up its borders? What lies w/in it?
- teres major, long head of triceps, humerus
- deep (profunda) brachial a. and radial n.
What nerve innervates all extensor mm. in the arm?
Radial nerve
What defines the apex of the axilla?
1st rib, clavicle, superior edge of the scapular
What defines the base of the axilla?
Concave skin, sub-Q tissue, axillary fascia (armpit)
What defines the anterior wall of the axilla?
Pec major and minor mm., pectoral and clavipectoral fascia
What defines the posterior wall of the axilla?
Scapula and subscapularis m.
What defines the medial wall of the axilla?
T-wall, 1st-4th ribs (serratus anterior m. covers the ribs)
What defines the lateral wall of the axilla?
Intertubercular groove of the humerus (plus coricobrachialis m.)
Branches of the axillary artery:
Screw The Lawyer, Save A Patient
- Superior thoracic a.
- Thoracoacromial trunk
- Lateral thoracic arteries
- Subscapular a.
- Anterior circumflex humeral a.
- Posterior circumflex humeral a.
What are the suspensory ligaments (of Cooper)?
Breast: attach lobes to skin & divide glandular tissue into lobes
How many glands form a breast lobe?
How many lactiferous ducts and sinuses are per gland?
80% of tumors originate where?
- 15-20
- 1
- Ducts
What 3 arteries supply the breast?
Lateral thoracic a., thoracoacromial (pectoral) a., internal thoracic a.
What are the 5 major lymph nodes of the breast?
CLASP
-central, lateral, apical, subscapular, and pectoral nodes
What breast quadrant has by far the highest rate of cancer?
Superior lateral quadrant
What does the pectoral fascia cover?
Covers pectoralis major
What does axillary fascia cover?
It’s a continuation of pectoral fascia laterally into the axilla
What are the branches of the thoracoacromial trunk (“The” lawyer of the axillary a. branch)
ACDP
Acromial, Clavicular, Deltoid, Pectoral
What are the branches of the subscapular artery (“Save” a patient of the axillary a. branch)
Circumflex scapular a. and thoracodorsal a.
In the arteriole supply to the shoulder, what’s a pathway where blood can bypass the axillary a.?
Subclavian a. –> suprascapular a. –> circumflex scapular a. –> subscapular a. –> axillary a.
- (suprascapular a. is in thyrocervical trunk of subclavian branch)
- (circumflex scapular a. is branch of subscapular a. from axillary branch)
