Surface Anatomy of Thorax, Lungs and Breast Fady Anis

Objectives Anterior Thoracic Wall Planes Surface markings Breast Lungs and Pleura

Anterior Planes 3 Anterior Planes 3 Anterolateral Planes Median Plane 2x Midclavicular Plane 3 Anterolateral Planes Anterior Axillary Plane Midaxillary Plane Posterior Axillary Plane

Other Surface Lines Sternal Angle – T4/T5 – Rib 2 Suprasternal – above sternum Xiphisternal – T9 – Rib 7 Subcostal – L3

Surface Markings Things to Notice: Clavicle – coronoid process Manubrium (Rib 1 and Rib 2 attach to the manubrium) – T3 – T4 12 pair of ribs – some people have 13 (cervical rib) – also identify true vs. false ribs and which part of the sternum they articulate to. Sternum T5- T9 –Rib 2-7 Xiphoid Process – T9 – Rib7 Sternal Angle/ Angle of louis – T4/T5 Jugular Notch – T2 8. Costal margin Costal Cartilage Coracoid process and acromion of scapula Subcostal angle Intercostal Space

The Breast The breast overlies the 2nd-6th Ribs Overlying pectoralis major and serratus anterior It contains ~20 lactiferous ducts opening into nipple Nipple is located at the 4th ICS – In males and varies in females Areola = Pigmented area around nipple The female breast develops during pregnancy due to prolactin along with progesterone and oestrogen and also at that same time you have hyperpigmentation of the areola. Lactiferous ducts are closed off with keratin plugs until the female has given birth in which then you have the release of breast milk.

The Breast Lymphatic Drainage 7 Lymph drainage sites : Apical Axillary LN Central Axillary LN Lateral Axillary LN Pectoral Axillary LN Supra/infra Clavicular LN Parasternal Nodes LN Abdominal LN These nodes are important as you have a feel of them if there is suspected breast cancer pathology. Enlarged lymph nodes could indicate breast cancer, it is important to test both breasts as the cancer can spread to the other breast via the parasternal lymph nodes.

Vasculature of the breast Medial mammary branches of anterior intercostal branches of the internal thoracic artery Lateral thoracic Thoraco-acromial arteries Posterior intercostal arteries, from the thoracic aorta

Lungs - Pleura The pleura of the lungs are divided into 2 different parts: Parietal Pleura = Adheres to the Internal thoracic wall Visceral Pleura = Attached to the lungs In between the two layers you have the pleural space which is filled with serous fluid reducing friction and provides surface tension to push parietal pleura against thoracic wall The parietal pleura has nervous innervation while the visceral pleura does not.

Pleural Parts 4 Pleural Parts Costal part- covers the internal surface of thoracic wall and is separated from wall by endothoracic fascia Mediastinal part- lateral aspects of mediastinum Diaphragmatic part- superior surface of diaphragm Cervical pleura- extends superior to thoracic inlet into the root of the neck

3 Pleural Reflections Pleural Reflections = Pleural folds / change in direction of pleura – 1 Anterior, 1 Posterior and 1 Inferior Sternal line – Costal Pleura continuous with mediastinal pleura Anteriorly Costal line – Costal pleura continuous with diaphragmatic Inferiorly Vertebral line – Costal pleura becomes continuous with mediastinal pleura Posteriorly The vertebral pleura is the most gradual reflection while the sternal reflection anteriorly is the steepest.

Parietal Vs. Visceral Pleura 2, 4, 6, 8, 10 Together cc2-4, cardiac notch to cc6, midaxillary cc8, rib 10 posteriorly Parietal pleura: 2, 4, 6, 8, 10, 12 Together cc2-4, cardiac notch to cc6, midclav cc8, midaxillary cc10, 12 rib posteriorly Parietal pleura is therefore larger than the visceral plaeura – in deep inhalation the lungs fill the costodiaphragmatic spaces. The costodiaphragmatic spaces and costomediastinal spaces can fill up with fluid during infection and compress the organs from moving.

Thoracic Dermatomes Nipple - T4 Xiphoid - T7 Umbilical – T10 Suprapubic – L1

Pleural Effusion

QUIZ! (T or F) The rib overlies Rib 2-6? True There are 4 pleural reflections – Diaphragmatic, Mediastinal, Cervical and costal ? False – there are 3 reflections – Sternal, vertebral and costal One of the lymph drainage sites is the medial axillary LN? False – Apical, pectoral central and lateral The four branches supplying the breast are Lateral Thoracic, medial mammary, thoraco-acromial and posterior intercostal arteries ?

Thank you for listening ! If you have any questions email the Fadz – Mzyfa1@nottingham.ac.uk