Thoracic Wall, Breast, Pleura & Lungs Lecture

Vocabulary flashcards summarizing key anatomical structures, vessels, lymphatics, muscles, and clinical landmarks of the thoracic wall, breast, pleura, lungs, mediastinum, and diaphragm.

Costal Facets – location

Found on the manubrium of sternum, body of sternum, transverse processes of thoracic vertebrae, and superior & inferior bodies of thoracic vertebrae

Clavicular Facets

Articular facets on the manubrium of sternum that form the sternoclavicular joint

Anterior Axillary Line

Surface‐anatomy line at the anterior border of the axillary fold

Posterior Axillary Line

Surface‐anatomy line along the posterior axillary fold bordered by latissimus dorsi

Scapular Line

Posterior longitudinal line passing through the inferior angle of the scapula

Anterior Median Line

Vertical line running down the mid‐sternum

Mid-Vertebral Line

Vertical posterior line following the spinous processes

Superior Thoracic Aperture

Thoracic inlet at vertebral level T1

Inferior Thoracic Aperture

Thoracic outlet closed by the diaphragm at T12

Costovertebral & Costotransverse Joints

Synovial gliding joints permitting rib elevation and depression

Costovertebral Joint Articulation

Between rib heads and costal facets of thoracic vertebral bodies and transverse processes

True Ribs – anterior attachment

Attach directly to sternum via their own costal cartilage

False Ribs – anterior attachment

Attach to grouped (shared) costal cartilage

Floating Ribs – anterior attachment

Have no anterior attachment

Intercostal VAN (order)

Within costal groove, from superior to inferior: Vein → Artery → Nerve

Intercostal Neurovascular Plane

Located between internal intercostal and innermost intercostal muscles

Primary Intercostal Arteries

Anterior intercostal, posterior intercostal, subcostal arteries

Posterior Intercostal Arteries – origin

Branch directly from thoracic aorta

Subcostal Artery – origin & level

Branch of thoracic aorta running below rib 12

Anterior Intercostal Arteries – origin

Branches of internal thoracic artery from subclavian artery

Pericardiophrenic Artery

Internal thoracic branch to pericardium and diaphragm

Medial Mammary Arteries

Perforating branches of internal thoracic artery to medial breast

Musculophrenic Artery

Internal thoracic branch supplying diaphragm

Superior Epigastric Artery

Continuation of internal thoracic artery behind rectus abdominis

Anterior Intercostal Veins – drainage

Empty into the internal thoracic vein

Azygos Vein – tributaries

Receives right posterior intercostal veins, accessory hemiazygos, hemiazygos veins

Accessory Hemiazygos – drainage

Drains left upper posterior intercostal veins

Hemiazygos Vein – drainage

Drains left lower posterior intercostal veins

Azygos Vein – termination

Empties into the superior vena cava

Accessory & Hemiazygos – cross level

Cross midline to azygos around T8–T9 (separately)

External Intercostal Muscle

Elevates ribs during inspiration; innervated by intercostal nerves; supplied by anterior & posterior intercostal vessels

Internal Intercostal Muscle

Depresses ribs during forceful expiration; intercostal nerve; anterior & posterior intercostal vessels

Subcostalis Muscle

Assists rib depression for respiration; intercostal nerve; posterior intercostal artery

Transversus Thoracis Muscle

Helps expiration; intercostal nerve; anterior intercostal & internal thoracic arteries

Innermost Intercostals – landmark

Best seen from inside posterior thoracic wall; VAN runs deep to them; most lateral layer

Breast Milk Pathway

Lobules → Lactiferous ducts → Lactiferous sinus → Nipple

Areola – function

Contains sebaceous & sweat glands that lubricate the nipple

Suspensory (Cooper’s) Ligaments

Fibrous bands anchoring breast to pectoral fascia

Retromammary Space

Loose tissue plane allowing breast movement on chest wall

Axillary Tail of Spence

Extension of breast tissue into axilla containing many lymph nodes

Lateral Mammary Artery – source

Branch of lateral thoracic artery

Medial Mammary Artery – source

Perforating branches of internal thoracic artery

Pectoral Artery

Branch of thoracoacromial trunk contributing to breast blood supply

Areolar Plexus

Superficial lymphatic plexus of breast where drainage begins

Parasternal Lymph Nodes

Receive medial breast lymph; drain to bronchomediastinal trunks

Right Bronchomediastinal Trunk – termination

Empties into right lymphatic duct

Left Bronchomediastinal Trunk – termination

Empties into thoracic duct

Axillary Lymph Nodes (Pectoral → Apical)

Receive lateral breast lymph; sequential groups lead to subclavian trunk

Subclavian Lymphatic Trunk – right side

Drains to right lymphatic duct then venous angle and SVC

Subclavian Lymphatic Trunk – left side

Drains to thoracic duct then left venous angle and SVC

Visceral Pleura

Serous membrane adherent to lung surface and fissures

Parietal Pleura

Serous membrane lining pleural cavity; includes cervical, mediastinal, costal & diaphragmatic parts

Mediastinum

Central thoracic compartment between lungs containing heart, great vessels, trachea, esophagus, lymph nodes

Oblique Fissure

Separates superior & inferior lobes of both lungs (and middle lobe on right)

Horizontal Fissure

Right lung fissure separating superior and middle lobes

Lingula

Tongue-like projection on left superior lobe

Cardiac Notch

Indentation in left lung accommodating the heart

Right vs. Left Lung Height

Right lung is shorter due to diaphragm’s higher right dome

Pulmonary Hilum Contents

Bronchi, pulmonary arteries, pulmonary veins

Right Lung Hilum Arrangement

Pulmonary artery located between bronchus and veins

Right Upper Lobe Bronchus Segments

Apical, anterior, posterior

Bronchus Intermedius

Shared airway giving rise to right middle and lower lobe bronchi

Right Mainstem Bronchus

Straighter, more vertical main bronchus; common path for aspirated objects

Left Upper Lobe – inferior branch

Lingular bronchus

Medial Basal Segment (Lung)

Typically absent in left lower lobe

Posterior Inferior Mediastinum – boundaries

Posterior pericardium, vertebral bodies, sternal angle above, diaphragm below

Esophageal Hiatus (T10)

Diaphragmatic opening for esophagus and vagal trunks

Caval Opening (T8)

Diaphragmatic aperture for inferior vena cava

Aortic Hiatus (T12)

Opening for aorta, thoracic duct, and splanchnic nerves

Diaphragm Blood Supply

Musculophrenic & pericardiophrenic (internal thoracic), superior phrenic (thoracic aorta), inferior phrenic (abdominal aorta)

Diaphragm Innervation

Phrenic nerve (C3–C5) – “C3, 4, 5 keeps the diaphragm alive”