Anatomy - Thorax Flashcards
What are the branches of the aortic arch
- brachiocephalic trunk (divides into right common carotid and right subclavian)
- left common carotid
- left subclavian
Describe the course of the thoracic aorta
- ascending aorta begins at aortic orifice
- ascends anterior to right pulmonary artery and bifurcation of trachea
- becomes arch at level of sternal angle (T4/T5), passes supero-posterior to the left
- passes over the root of the left lung
- descends posterior to left lung root at T4 level
- arch becomes descending aorta at level of sternal angle (T4/T5)
- continues to level of T12, where it exits the aortic hiatus to become the abdominal aorta
Model of clavicle: identify parts of a clavicle and demonstrate muscular attachments
- deltoid: lateral 1/3 anterior
- trapezius: lateral 1/3 posterior
- pectoralis major: medial 1/3 anterior-inferior
- sternocleidomastoid: clavicular head, medial 1/3 anterior
- subclavius: inferior middle 1/3
What are the anatomical relations of the medial 1/3 of the clavicle
medial:
sternoclavicular joint
posterior: first rib ijv subclavian vein brachiocephalic vein
Describe the course of the subclavian vein
- becomes subclavian vein from the axillary vein medial to outer border of 1st rib
- courses medially posterior to clavicle and superior to first rib
- lies anterior to anterior scalene, which separates it from the subclavian artery
- becomes brachiocephalic vein at medial border of anterior scalene, joins the IJV
CXR image: outline the structures that make up the cariomediastinal borders on a CXR
trachea = 1 aortic arch = 2 left pulmonary artery = 3 left atrium = 4 left ventricle = 5 left cardio-phrenic angle = 6 superior vena cava = 7 right pulmonary artery = 8 right atrium = 9 inferior vena cava = 10 right costophrenic angle = 11
What structures are located at the same level as the sternal angle
- bifurcation of the trachea, division of the pulmonary trunk, SVC, hila of lungs
- ascending aorta becomes arch, arch becomes descending aorta
- phrenic nerve, vagus nerve, azygous vein, thoracic duct
Describe the lobes of the lungs and their fissures
right lung:
3 lobes = superior, middle, inferior
-superior lobe separated from middle lobe by horizontal fissure
-middle lobe separated from inferior lobe by oblique fissure
left lung:
2 lobes = superior and inferior
-superior lobe separated from inferior lobe by oblique fissure
What lobes of the lung lie adjacent to right and left cardio-mediastinum
- right upper mediastinum = right superior lobe
- right heart border = right middle lobe
- left upper mediastinum = left superior lobe
- left heart border = left superior lobe
CXR image: demonstrate the lobes and fissures of the lung
- horizontal fissure: follows level of 4th costal cartilage
- oblique fissure: from T2 posteriorly to 6th costal cartilage anteriorly
How do you differentiate between RLL and RML pneumonia on CXR
right middle lobe pneumonia has loss of the right heart border
Describe parietal pleura surface anatomy
- 3cm over medial 1/3 clavicle
- converge at T2
- diverge on left at 4th costal cartilage
- diverge on right at 6th costal cartilage
- mid clavicular line at 8th rib
- mid axillary line at 10th rib
- mid scapular line at 12th rib
- lung edge is 2 ribs higher
Identify the diaphragm and its attachments
- sternal part: posterior surface of xiphoid process
- costal part: lower six ribs and costocartilage
- lumbar (crural) part: medial and lateral arcuate ligaments and bodies of L1-L3
What are the openings of the diaphragm
- T8 = IVC, right phrenic nerve
- T10 = esophagus, vagal trunk
- T12 = aorta, thoracic duct, azygous vein
What is the nerve supply of the diaphragm
phrenic nerve (C3, C4, C5)
Motor: phrenic nerve (C3-C5)
Sensory:
- central portion: phrenic nerve
- peripheral portion: intercostal (T5-T11), subcostal (T12)
What is the ligamentum arteriosum
remnant of the ductus arteriosum
connect pulmonary trunk to arch of aorta, allowed blood to bypass the lungs