Anatomy Flashcards
Anatomical borders of the mediastinum
Sternum - body of vertebra
Superior thoracic aperture - diaphragm
Lungs on sides
What are the contents of the anterior mediastinum?
Sternopericardial ligaments: connect sternum to the fibrous pericardium, thymus (children), thoracic artery + branches, lymphatics
What’s in the middle mediastinum?
The heart
Parietal pericardium adheres to what?
Fibrous pericardium (tough CT)
*serous layer surrounds heart
What’s in the posterior mediastinum (7)? What is it particularly susceptible to?
thoracic (descending) aorta, azygous vein, thoracic duct, esophagus, VAGUS and splanchnic nerves, posterior mediastinal lymph nodes,
Large communication channel; infections, tumours, etc
One sign and three symptoms of mediastinitis
Mediastinum shifts away from fluid
SOB, dysphagia, hoarse voice
What does the phrenic N supply and what are its roots?
Diaphragm, pericardium C3-5
What’s the transverse pericardial sinus, what can it be used for in surgery?
Posterior to pulmonary trunk, anterior to SVC
Clamped in surgery to stop arterial blood flow
What happens if you have damage to the papillary muscles?
Valve incompetence and cardiac murmur
Name 3 things that aid the valves?
Chordae tendinae “heart strings”, papillary muscles, cardiac fibrous skeleton
What prevents electrical signals from being mixed between the atria and ventricles?
Fibrous Tissue
Describe the structure of aortic/pulmonary valves
3 cusps: semilunar
*Diastole: backwards bloodflow fills up pockets, rapid ejection in systole pushes cusps against vessel wall
Where does the L coronary supply
Widowmaker/LAD/AIVA: bulk of ventricles, anterior 2/3 septum
Circumflex; L atrium and ventricle, PDA (AV node + posterior 1/3 septum) in L dominant circulation (rare)
What can branch of the R coronary artery
PIVA: AV node, posterior 1/3 septum
*R dominant circulation (common)
SA node artery: node, both atria
Marginal artery: reaches apex
Where does the bulk and the minority of cardiac venous drainage go through?
Bulk: coronary sinus
Minority: some independent anterior veins drain directly into R atria
What are the direct openings in the heart wall that return venous drainage into heart chambers called?
venae cordis minimi
Where should the apex of the heart be on a chest?
3.5 inches away from the sternum in 5th ICS
Which intercostal spaces and heart chambers make up the bulk of the R and L sides of the heart?
L: 2-5 ICS, L ventricle
R: 3-6 ICS, R atria
Where do you auscultate for each valve?
Mitral: 5th ICS, Left mid-clavicular
Tricuspid: 4th ICS, left sternal border
Pulmonary: L sternal edge, 2nd ICS
Aortic: R sternal edge, 2nd ICS
What’s the name of the smooth wall part of R ventricle and what did it develop from?
Conus arteriosus, bulbus cordis
Name which nerves give sympathetic and parasympathetic innervation to the heart, which is associated with referred cardiac pain?
Sympathetic: T1-T4 derived parts of sympathetic chain, visceral sensory fibres travel back to CNS with sympathetic nerves
Parasympathetic: VAGUS
What does the fibrous pericardium bind to inferiorly?
Central diaphragmatic tendon
What symptoms can result from decreased perfusion to the R coronary?
Arrhythmia, bradycardia
*supplies SA node
Which vertebral level is a deep injury detrimental?
T4/T5 - 2nd costal cartilage
