Flashcards in The axilla and pectoral region Deck (72)
Osteology of the Pectoral Region
Parts of the sternum
Manubrium, body, and xiphoid
1, 2, 11, and 12
"True" ribs (vertebrocostal)
"False" ribs (vertebrochondral)
Ribs 11 and 12
Bilateral glandular structures found in both males and females.
What are mammary glands?
Modified sweat glands
Where do breast rest?
Rest on pectoral fascia (above pectoralis major)
Potential space between breast and pectoral fascia
Innervation of the Breast
Innervated by intercostal nerves (4th-6th)?
May also receive some innervation from supraclavicular nerve branches of other intercostal nerves
How does the breast attach to the dermis of the overlying skin?
Suspensory ligaments (Cooper's ligaments)
Arterial Supply of the Breast
Mammary branches from anterior intercostal, lateral thoracic, and internal thoracic arteries.
Axillary and subclavian
Venous Drainage of the Breast
Mainly to axillary vein via lateral thoracic veins and medial mammary veins
Some drainage to internal thoracic vein via anterior intercostal veins
Why is lymphatic drainage of breast tissue important?
Due to its role in metastasis of cancer cells
Lymphatic drainage of nipple, areola, lactiferous lobules
Subareolar lymph nodes
What lymph nodes are responsible for more than 75% of lymph from breast?
Axillary lymph nodes (pectoral, central, apical)
Fascia of the pectoral region
Clavipectoral fascia (Pectoralis minor)
Pectoral fascia (Pectoralis major)
Anterior and lateral branches of intercostal nerves
Components of the Deltopectoral (clavipectoral) triangle
Deltoid, pectoralis major, middle 1/3 of clavicle (Make up borders)
Deltopectoral lymph nodes
Deltoid branch of thoracoacromial a. (from axillary a.)
Clavipectoral fascia invests..
Subclavius and pectoralis minor
Clavipectoral Fascia attaches to
the clavicle and anterior thoracic wall
What pierce the clavipectoral fascia?
Cephalic vein, thoracoacrimial artery, and lateral pectoral nerves
What does the clavipectoral fascia become?
Becomes suspensory ligament of axilla
Innervation of the muscles of the pectoral region
Innervated by the ventral rami of spinal nerves via branches of the brachial plexus
Proximal attachment of pectoralis major
Claviclular and sternocostal attachments
Ant. surface of medial 1/2 of clavicle
Ant. surface of sternum and superior 6 costal cartilages
Distal attachment of pectorallis major
Lateral lip of intertubercular sulcus (bicipital groove)
Actions of pectoralis major
Adducts and medial rotates humerus
Draws scapula anteriorly and inferiorly (via clavicle)
Clavicular portion flexes humerus
Sternal portion can extend humerus while it is in this flexed position
Innervation of pectoralis major
Lateral and medial pectoral nerves (C5, C6 clavicular portion; C7, C8, T1 sternocostal portion)