Main Structures of the Thorax Flashcards
Pericardium
Sac in which the heart sits
Divided into tough fibrous (outer) and serous (inner) parts which surround the heart
Fibrous Pericardium
Tough and not distensible; attached to diaphragm by pericardiophrenic ligaments; blend into adventitia of great vessels
Serous Pericardium
Inner pericardial layer
Comprised of visceral layer (epicardium) and parietal layer (lining fibrous pericardium); potential space (pericardial cavity) between them
Lines fibrous pericardium
Both composed of a flattened layer of epithelial cells (mesothelium)
Surfaces of the heart
Anterior/Sternocostal
Inferior/Diaphragmatic
Posterior/base
Pulmonary
Anterior/Sternocostal Surface
Formed mostly of right (with a bit of left) ventricle
Inferior/Diaphragmatic
Mostly L (bit of R) ventricle
Posterior/Base surface
Mostly L (bit of R) atrium and pulmonary vein
Pulmonary Surface
Mostly L ventricle, in cardiac notch of L lung
Borders of Heart
Superior Border
Right Border
Inferior Border
Left Border
Remember
2 3 ics5 6
Superior Border of the Heart
L cc2 - R cc3
Right Border of the Heart
Convex to R
R cc3 –> R cc6
Mainly R atrium with SVC and IVC
Inferior Border of the Heart
Lies on diaphragm central tendon
R cc6 –> L intercostal space 5
Mainly R ventricle and some LV
Left Border of the Heart
Convex to L
From L ics5 and back to L cc2
Mainly LV and maybe some LV
Valve positions (normal situation)
Valves are retrosternal in position and close to the midline
Pulmonary - medial to L cc3
Aortic - medial to L ics3
Bicuspid/Mitral - Medial to L cc4
Tricuspid - Medial to R ics4
Valve Sounds
Summary of Heart Locations for Auscultation
Pleura
Serous membrane divided into parietal (outer) and visceral (inner) layers which surround the lungs and contain the pleural cavities; layers also separated by small amounts of serous fluid
Parietal pleura
Lines thoracic cavity lateral to mediastinum; supplied by intercostal and phrenic nerves; sensitive to pain
Visceral pleura
Covers lung and follows lung fissures; supplied by autonomic nerves (doesn’t feel pain i think)
Pleuritis/Pleurisy
Inflammation of the pleura
Usually appears as localised roughness and redness; pleural rub can be heard with stethascope; leads to chest pain (usually sharp) when breathing or coughing
Name the Surfaces of Lungs and vaguely what they face/contain
Green: Mediastinal
Flat, faces mediastinum, contains hilum
Purple : Diaphragmatic
Convex, faces diaphragm
Red: Costal
Convex, faces ribs
Blue: Cervical
Extends into neck
Pleural Reflections
Abrupt lines along which the pleura changes directions (reflects) from one wall of pleural cavity to another
Occurs where costal pleura becomes continuous with mediastinal pleura anteriorly and posteriorly and with diaphragmatic pleura inferiorly
Why are pleural reflections important to know
Correct interpretation of chest X-ray and performing procedures like thoracentesis correctly
Remember 2,4,6,8,10,12
Visceral Pleural Reflections
2,4,6,8,10
Parietal Pleural Reflections
Lobes of Right Lung
Lobes of Left Lung
Bronchopulmonary Segments
you do NOT need to know them, just understand how it works
Be aware of lobes of lung in x-ray
How can a tumour in a bronchopulmonary segment be treated
That segment is removed individually as opposed to the whole lobe or lung
In which segments of the lung is fluid most likely to collect
Apical and Posterior segments in both the left and right lung
Aortic Branches
Mneumonic device - remember your ABCs
A - Aortic Arch
B - Brachiocephalic Trunk
C - (Left) Common Carotid a
S - (Left) Subclavian a
Note: Right common and subclavian arteries are on the brachiocephalic trunk; the one closer to the Vena cava is the right subclavian
Thoracic and Abdominal Aorta
Exactly what they sound like (one is in thoracic, the other is in abdominal cavity)
Where do the posterior and anterior intercostal arteries come from; where do they run
Anterior intercostal arteries come from the internal thoracic artery
Posterior intercostal arteries come fro the thoracic aorta
They run in the costal groove below each rib
Azygous system
Azygous vein drains into SVC; be vaguely aware of how this drains
The system drains the posterior thoracic wall
Costodiaphragmatic recess vs costophrenic
The recess is the potential space where fluid would collect but normally the angle is referred to as the costophrenic angle of the lung
