Pectoral and Axillary Regions Flashcards
Osteology of the Pectoral Region
clavicle
sternum (manubrium, body, xiphoid)
ribs
scapula
Atypical Ribs
1, 2, 11, and 12
True Ribs (vertebrocostal)
1-7
False Ribs (vertebrochondral)
8-10
Floating Ribs
11-12
The Breast
cutaneous modified sweat glands on pectoral fascia retromammary spaces b/w breast and pectoral fascia inn. by intercostal n. 4-6 attached to skin by Cooper's Ligaments mammary glands lobules converge on the nipple 15-20 lactiferous ducts open at nipple
Arterial Supply - Breast
mammary branches from anterior intercostal, lateral thoracic, and internal thoracic arteries
Venous Drainage - Breast
mainly to axillary vein via lateral thoracic veins and medial mammary veins
some drainage to internal thoracic vein via anterior intercostal veins
Lymphatic Drainage - Breast
more that 75% of lymph from breast - AXILLARY lymph nodes
nipple, areola, lactiferous lobules - subareolar lymph nodes
remaining lymph - parasternal and abdominal lymph nodes
Innervation - Breast
mainly from ANT. and LAT. BRANCHES of the 4th-6th INTERCOSTAL N.
some from supraclavicular n branches as well as branches of other intercostal n.
Polymastia and Polytheia
accessory breast and accessory nipples along the mammary ridge
Superficial Fascia - Pectoral Region
platysma
supraclavicular n.
anterior and lateral branches of intercostal n.
Deltopectoral (clavipectoral) Triangle
deltoid, pectorals major, middle 1/3 of clavicle make up borders
cephalic vein
detopectoral lymph nodes
deltoid branch of thoracoacromial a. (from axillary a.)
Clavipectoral Fascia
invests subclavius and pectoralis minor
attaches to clavicle and anterior thoracic wall
cephalic vein, thoracoacromial a, and lateral pectoral n pierce it
becomes suspensory ligament of axilla
Pectoralis major m.
Actions: ADducts and medial rotation of humerus, flexion of humerus (clavicular portion), anteriorly and inferior movement of scapula, extend humerus while flexed (sternal portion)
Blood supply: pectoral branch of thoracoacromial arterial trunk
Inn: lateral and medial pectoral n.
Pectoralis minor m.
Actions: stabilizes scapula by pulling it anteriorly and inferiorly agains posterior thoracic wall
Blood supply: pectoral branch(es) of thoracoacromial arterial trunk
Inn: medial pectoral n. (usually pierced by this nerve)
Subclavius m.
Actions: anchors and depresses clavicle
Blood supply: clavicular branch(es) of thoracoacromial arterial trunk
Inn: nerve to subclavius (C5,C6)
Serratus anterior m.
Actions: protracts scapula, rotates scapula, holds scapula agains thorax
Blood supply: latera thoracic a.
Inn: long thoracic n.
Axillary a. Pt. 1
superior thoracic a.
Axillary a. Pt. 2 - Throacoacromial trunk
pectoral branch
deltoid branch
acromial branch
clavicular branch
Axillary a. Pt. 3 - distal/lateral to P. minor
subscapular a. (circumflex scapular and thoracoodorsal)
anterior circumflex humeral
posterior circumflex humeral
Venous Drainage - Pectoral Region
drained by axillary vein
Axillary vein
deep brachial veins
superficial veins of arm and forearm (basilic and cephalic veins)
Basilic v.
continues as axillary vein
Cephalic v.
drains into axillary before it becomes subclavian vein
Boundaries of the Axilla
a pyramid shaped space apex base (A&P axillary folds) anterior wall posterior wall medial wall lateral wall
Apex of Axilla
clavicle
scapula
1st. rib
Base of Axilla
skin and superficial fascia
ant. axillary fold - pectoralis major
post. axillary fold - LATS and teres major
chest wall - serratus anterior
Anterior Wall of Axilla
clavicle
subclavius
pectoralis major
pectoralis minor
Posterior Wall of Axilla
scapula
subscapularis
latissimus dorsi
teres major
Lateral Wall of Axilla
intertubercular sulcus
tendon of long head biceps
coracobrachilalis tendon
Axillary sheath
axillary v.
axillary a.
brachial plexus
