List the layers associated with the breast starting with the skin
Epidermis-> Dermis -> Breast in Superficial fascia (subcutaneous tissue) -> retrommary space -> deep fascia -> pectoralis major muscle
What is the retromammary space and where is it located?
Allows for movement of the breast. Located between superficial fascia and deep fascia
What are the four quadrants of the breast? Where is the axillary tail located?
UOQ, UIQ, LOQ, LIQ
Axillary tail in UOQ (extends into axilla)
Describe the ductal system of the breast.
Mammary gland -> 15-20 lobes each with a lactiferous duct -> lobules -> alveoli
What are suspensory ligaments?
Connect the lobular tissue with the overlying dermis to support breast
What is the blood supply to the breast? What are its branches?
Internal thoracic artery
Branches of the axillary artery and intercostal arteries
What are the four lymph pathways for drainage in the breast? What is the most common?
1. axillary lymph nodes (75% of lymph drainage): outer quadrants
2. Parasternal (internal thoracic) nodes: inner quadrants
3. Cervical nodes
4. Abdominal nodes
The ribs allow movement in which planes?
Coronal (bucket handle) and saggital (pump handle)
True ribs vs. False ribs
True ribs: first 7 pairs articulate with the sternum (breast bone)
False ribs: 11-12 do not articulate with anything
Diaphragm: What cavities does it separate? Is is somatic or visceral?
1. Separate thoracic and abdominal cavities
2. Somatic structure - No sympathetic innervation
1. What are they? How many
2. What is within these spaces?
1. Between ribs, 11 total
2. Contain intercostal muscles (external, internal, innermost), arteries, veins, and nerves
What is thoracentesis? Where should it be performed?
What is the location of the intercostal nerves, arteries, and veins?
1. Remove air/fluid from pleural cavity
2. Needle should be at inferior border of intercostal space or superior to the rib
3. VAN mnemonic: Veins, arteries, nerves at the superior intercostal space
2 primary sources of blood supply in the thorax. What does it branch to? What if one artery is blocked?
1. Thoracic aorta (left of sternum) -> posterior intercostal arteries
2. Internal thoracic arteries (parallel to sternum) -> anterior intercostal arteries
3. Anterior and posterior intercostal arteries have anastomoses -> collateral circulation
What are the major nerves of the thoracic?
1. Intercostal nerves (T1-T11): efferent innervation to thoracic wall, afferent to overlying skin
2. Subcostal nerve (T12)
Upper and lower boundaries of the thoracic cavity
1. Superior thoracic aperture (plane of 1st rib): apex of lung extends above it (prone to injury)
Pleural reflection vs. Pleural recess
Reflection: transitioning of one parietal pleura to another
Recess: Overlap of two pleura (costodiaphragmatic recess)
How many lobes on each lung?
What are the dominant lobes anteriorly and posteriorly?
Right: 3 lobes (superior, middle, inferior) using 2 fissures (horizontal and oblique)
Left: 2 lobes (upper, lower) using 1 fissure (oblique)
Anterior: upper and middle lobes on the right and upper lobe alone on the left
Posterior: lower lobes on both sides
Divisions of the bronchi + how many total
1. Main primary bronchi (2 total)
2. Lobar secondary bronchi (5 total)
3. Segmental tertiary bronchi (many)
How many lobar bronchi does the right lung have?
3 lobar bronchi (one for each lobe)
What is the intermediate bronchus?
segement of right main bronchus before the middle and lower lobe bronchus branch
Which bronchi is more prone to stridor (foreign bodies)? Why
Right bronchus: Larger diameter and more vertical orientation
Location of the lungs and pleura in relation to the thoracic cage?
Lung: 6-8-10 (midclavicular=anterior, midaxillary, midscapular=posterior)
Pleura: 8-10-12 (midclavicular=anterior, midaxillary, midscapular=posterior)
Pleura extends to the lowest thoracic (T12) on the posterior side
What is the hilum of the lung?
area on the central portion of each lung where the bronchi, arteries, veins, and nerves enter and exit the lungs
parietal and visceral pleural membranes join at hilum
What are the two lymph nodes of the lung
1. Bronchopulmonary nodes: lobar and main bronchi at the hilum
2. Tracheobronchial nodes: carina of trachea
What are synonyms of sternal angle? Which rib articulates on it?
Sternal angle = Manubrial = Angle of Louis
2nd rib articulates onto sternal angle
What is the cupula?
Cervical parietal pleura
Where would you perform an intercostal block for anaesthesia?
Place needle in the superior intercostal space to deaden the nerve
What external landmark is
used to facilitate counting of
the ribs on physical exam?
Manubrial/Sternal angle (of Louis): articulates with the second rib
Where does the tubercle of the rib articulate on with respect to the vertebral level?
On the same level