Flashcards
The mediastinum
Cards in this deck (37)
- 11) Identify the divisions of the mediastinum 2) Describe the organisation of the structures in the superior mediastinum 3) Describe the arrangement of the pericardium 4) Describe the contents of the posterior mediastinum 5) Explain the arterial supply and the venous drainage of the thoracic wall 6) Distinguish between the pulmonary and the systemic blood supply to the lungsX
- 2Describe the boundaries of the mediastinum (4)1) Superiorly - thoracic inlet/aperture (~T1)
2) Inferiorly - diaphragm
3) Anteriorly - sternum and costal cartilages
4) Posteriorly - thoracic vertebrae - 3What is the function of the mediastinum?Highly mobile and allows the movement of the lungs, heart, great vessels and oesophagus.
- 4What are the two major divisions of the mediastinum? What divides them?1) Superior and inferior mediastinum
2) The transthoracic plane - located at the manubriosternal joint (sternal angle) at T4/T5 - 5Where (at what levels) are the aortic arch, trachea and central tendon located within the mediastinum when in the supine position?1) The aortic arch is located above the the transthoracic plane
2) The bifurcation (carina) of the trachea is located at the transthoracic plane
3) The central tendon is located at the xiphisternal junction ~T9 - 6Where (at what levels) are the aortic arch, trachea and central tendon located within the mediastinum when in the standing position?1) Aortic arch is transected by the transthoracic plane
2) The trachea bifurcation lies inferiorly to the transthoracic plane
3) The central tendon lies at T9-T10 (IV disc) - 7Describe the contents of the superior mediastinum1) Trachea
2) Oesophagus
3) Thymus
4) Brachiocephalic vein and superior vena cava
5) Phrenic nerve
6) Vagus nerve and recurrent laryngeal
7) Thoracic duct and lymphatic trunks - 8—1) Ascending aorta
2) Aortic arch
3) Right brachiocephalic trunk
4) Right subclavian
5) Right vertebral artery
6) Right internal thoracic artery
7) Right thyrocervical trunk
8) Should be right common carotid
9) Left common carotid
10) Left subclavian
11) Left vertebral artery
12) Left internal thoracic artery
13) Left thyrocervical trunk - 9What do the vertebral arteries pass through and supply?Pass through the transverse foramen and then the foramen magnum to predominantly supply the cerebellum.
- 10What do the thyrocervical arteries supply?The head and neck
- 11What mediastinal structures does the vagus nerve innervate? What structure(s) come off the vagus nerve?1) The heart, bronchi and oesophagus
2) The recurrent laryngeal - loops under the aorta on the LHS and right subclavian on the RHS. Also the oesophageal plexus - 12What does the phrenic nerve innervate? What structures does it run between?1) Provides motor to the diaphragm and sensory to the pericardium.
2) The pleural and pericardial cavities - 13Why structures are most likely to be injured during thyroid surgery?The LHS vagus and recurrent layrngeal
- 14What causes phrenic nerve damage?Cancer metastasis and lymph node removal - damage usually occurs to LHS resulting in intestines being pushed up on the left hand side.
- 15What spinal levels are the trachea located at? Where is the carina? Where is the thoracic inlet?1) C6-T4
2) T5/T6
3) C6 - 16What are the spinal levels associated with the oesophagus? Where is the oesophagus in relation to the trachea? Describe the positioning of the oesophagus.1) C6-T10
2) Immediately posterior to the trachea
3) Bends towards to the left (but stopped by the aorta) to the stomach - 17What does the aorta loop over?Left bronchus and main left root
- 18How does the trachea change from the neck to the mediastinum?Trachea becomes flatter and more muscular in the mediastinum than it is in the neck - Increase muscle and cartilage helps to prevent it being crushed by the aorta.
- 19What is the inferior mediastinum divided into?1) Anterior
2) Middle
3) Posterior - 20What is located in the anterior mediastinum?The thymus
- 21What is located in the middle mediastinum?The heart and pericardium
- 22What is located in the posterior mediastinum?1) Primary bronchi
2) The oesophagus and oesophageal plexus
3) The descending aorta
4) The thoracic duct
5) The hemizygous and azygous veins - 23What are the different components and their function of the pericardium?1) Fibrous pericardium - prevents over-dilatation, limits growth, protects heart and attaches to diaphragm, aorta, superior and inferior vena cava and pulmonary artery to anchor the heart in place
2) Serous and parietal pericardium - potential space between the two, allows movement of heart - 24What does the parietal pericardium attach to?The fibrous pericardium
- 25Where does a pericardial effusion/tampenade take place? How much fluid needs to build up acutely vs chronically to be considered a pericardial effusion?1) Between the serous and parietal membranes - the fibrous pericardium
2) 150ml acutely up to 1,000ml chronically - 26What does a pericardial tampenade result in?1) Decreased SV
2) Increased venous pressure resulting in both raised systemic pressure and a raised JVP - 27Describe the superior border, left border, inferior border and right border of the heart.1) Superior border travels from left inferior second costal cartilage to the superior aspect of the third costal cartilage on the RHS.
2) The left border is from the 3rd costal cartilage to the 6th costal cartilage, convex shape
3) From the fifth costal cartilage to the midclavicular line
4) Joins the inferior and superior borders - 28Describe the organisation of the posterior mediastinumPulmonary arteries lie superiorly, then the trachea and then the descending aorta (aortic trunk branches over left bronchus).
- 29What gives rise to the anterior intercostal arteries? Posterior intercostal arteries? What do they run in?1) The internal thoracic
2) The descending aorta
3) Within neurovascular bundles (VAN) in the intercostal groove which located inferiorly in each rib - 30What is the exception to the origin of the posterior intercostal arteries?The first two posterior intercostal arteries arise from the costocervical branch of the subclavian.
- 31What is contained within the intercostal nerves?Ventral rami of the corresponding thoracic nerves - contain S + M + sympathetic
- 32Where are the collateral branches which supply the thoracic wall located?Inferiorly to the main neurovascular bundle - superior to the costal cartilage at the bottom of the intercostal space.
- 33What is a thoracentesis?Sampling of excess fluid around the lungs - taken from 9th intercostal space at the midclavicular line to avoid inferior border of lung. Taken just superior to cartilage but must be careful to avoid collateral neurovascular bundles.
- 34—x
- 35Describe the venous return from the thoracic wall.1) The RHS drains in the azygous which drains into the superior vena cava
2) The LHS drains into the hemiazygous and accessory hemiazygous - these then drain into the azygous or into the left brachiocephalic before draining into the superior vena cave. - 36—X
- 37—X
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- Cardiorespiratory (Cardiac anatomy ) Flashcards on The mediastinum, created by Anna Hogarth on 18/12/2017.
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- Anna Hogarth
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