Chest Flashcards
Structures surrounding R mainstem bronchus, length, branches
azygos v. arches over, PA first below then anterior to RMB, 2.5cm in adults, R upper bronchus and bronchus intermedius
Mediastinal anatomy
A = Apical segmental bronchus
B = Posterior segmental bronchus
C = Anterior segmental bronchus
D = Bronchus intermedius
E = Truncus anterior
F = Carina
G = Right main pulmonary artery
H = Left main pulmonary artery
I = Right inferior pulmonary artery
J = Right superior pulmonary vein
K = Right middle lobe bronchus
L = Right lower lobe bronchus
M = Right inferior pulmonary vein
N = Left Atrium
O = Left superior pulmonary vein
P = Apicoposterior segmental bronchus
Q = Left upper lobe bronchus
R = Lingular bronchus
S = Left inferior pulmonary artery
T = Left inferior pulmonary vein
Left mainstem bronchus - length, relation to aortic arch, structures posterior and inferior; position of both left lobe bronchi relative to PA
2.5cm in adults, passes under arch, posteriorly esophagus and thoracic duct located, inferiorly L PA is located; both bronchi lie below PA
Why does aspiration lung abscess/pneumonia occur in the superior segment of lower lobes?
85% of aspiration lung abscesses occur in superior segment of lower lobes and axillary sub-segment of upper lobes. This is again a gravity dependant phenomenon. Location of aspiration depends on the position of patient at the time of aspiration. You also need to have an understanding of three dimentional view of bronchial anatomy. If the patient is supine on back, the first dependant entry is into the superior segment of lower lobe. If the patient is in right lateral decubitus position, it is the axillary sub-segments of RUL. If you are in supine positionwith face down, aspiration into lungs does not occur. Hence it is very unusual to encounter aspiration lung abscesees in anterior segemnets.
Bronchial anatomy
A = Right Main Stem Bronchus
B = Right Upper Lobe Bronchus
B1 = Apical Segmental Bronchus
B2 = Anterior Segmental Bronchus
B3 = Posterior Segmental Bronchus
C = Bronchus Intermedius
D = Right Middle Lobe Bronchus
D4 = Lateral Segmental Bronchus
D5 = Medial Segmental Bronchus
E = Right Lower Lobe Bronchus
E6 = Superior Segmental Bronchus
E7 = Medial Basal Segmental Bronchus
E8 = Anterior Basal Segmental Bronchus
E9 = Lateral Basal Segmental Bronchus
E10 = Posterior Basal Segmental Bronchus
F = Left Main Stem Bronchus
G = Left Upper Lobe Bronchus
G1, G2 = Apicoposterior Segmental Bronchus
G3 = Anterior Segmental Bronchus
H = Lingular Bronchus
H4 = Superior Lingular Segmental Bronchus
H5 = Inferior Lingular Segmental Bronchus
I = Left Lower Lobe Bronchus
I6 = Superior Segmental Bronchus
I7 = Medial Basal Segmental Bronchus
I8 = Anterior Basal Segmental Bronchus
I9 = Lateral Basal Segmental Bronchus
I10 = Posterior Basal Segmental Bronchus
SMALP = “Suppose My Aunt Loves Peaches” is a helpful way to remember the segmental lower lobe bronchi.
Approach to reading a chest x-ray
Turn off stray lights, optimize room lighting, view images in order
Patient Data (name history #, age, sex, old films)
Routine Technique: AP/PA, exposure, rotation, supine or erect
Trachea: midline or deviated, caliber, mass
Lungs: abnormal shadowing or lucency
Pulmonary vessels: artery or vein enlargement
Hila: masses, lymphadenopathy
Heart: thorax: heart width > 2:1 ? Cardiac configuration?
Mediastinal contour: width? mass?
Pleura: effusion, thickening, calcification
Bones: lesions or fractures
Soft tissues: don’t miss a mastectomy
ICU Films: identify tubes first and look for pneumothorax
Chest x-ray structures
SVC
formed by union of 2 brachiocephalic veins to R of sternum at level of 1st intercostal space, no valves, empties into RA at R 3rd costal cartilage, azygos vein and small pericardial and mediastinal vessels drain into it before it pierces the pericardium
Azygos vein system - origins, drainage, blood flow
- hemiazygos and azygos arise in abdomen continuing from ascending lumbar veins (azygos on R, hemoazygos on L)
- unite at T7, parallel veins flank vertebral column on each side and receive blood from intercostal, esophageal and bronchial venous flow
- main trunk drains into SVC
- variable blood flow depending upon pressure/gravity, can carry blood from portal system, parietal, vetebral, cervical and internal mammary veins, SVC may drain into IVC via azygos system and vice versa
Horner’s syndrome
apical lung tumor - damage sympathetic chain and as it grows larger involves brachial plexus
Thymus gland - newborns, arterial supply, veins
- newborns - 2 elongated lobes anterosuperior to great vessels and trachea, may extend to neck as far as hyoid and inferiorly to xiphoid
- internal mammary arteries
- veins
- resected occasionally in myasthenia gravis, thymus tumors
Differential for anterior chest wall mass
Thymoma
Terrible lymphoma
Teratoma
Retrosternal Thyroid
Mediastinum classification (contents)
Anterior - thymus (inferior portion), LN, branches of internal thoracic vessels
Middle - heart, epicardium, great vessels (ascending aorta, pulmonary vein, pulmonary artery), phrenic nerves, bronchial LN, lung roots
Posterior (posterior to pericardum) - thoracic descending aorta, azygos and hemiazygos, esophagus, thoracic duct, LN, trachea, vagus, sympathetic nerves, splanchnic nerves
Esophagus length
mouth (upper incisors) to cardia ~40cm
cricopharyngeus to stomach ~25cm
where it crosses L main bronchus ~7.5-8.75cm
Esophageal narrowings (3)
- cricopharyngeus (level of cricoid cartilage) = narrowest
- behind tracheal bifuration (bronchoaortic area) = 2nd narrowest
- passage through esophageal hiatus into abdominal cavity
