Anatomy

Question 1

Anatomical borders of the mediastinum

Answer 1

Sternum - body of vertebra
Superior thoracic aperture - diaphragm
Lungs on sides

Question 2

What are the contents of the anterior mediastinum?

Answer 2

Sternopericardial ligaments: connect sternum to the fibrous pericardium, thymus (children), thoracic artery + branches, lymphatics

Question 3

What’s in the middle mediastinum?

Answer 3

The heart

Question 4

Parietal pericardium adheres to what?

Answer 4

Fibrous pericardium (tough CT)

*serous layer surrounds heart

Question 5

What’s in the posterior mediastinum (7)? What is it particularly susceptible to?

Answer 5

thoracic (descending) aorta, azygous vein, thoracic duct, esophagus, VAGUS and splanchnic nerves, posterior mediastinal lymph nodes,

Large communication channel; infections, tumours, etc

Question 6

One sign and three symptoms of mediastinitis

Answer 6

Mediastinum shifts away from fluid

SOB, dysphagia, hoarse voice

Question 7

What does the phrenic N supply and what are its roots?

Answer 7

Diaphragm, pericardium C3-5

Question 8

What’s the transverse pericardial sinus, what can it be used for in surgery?

Answer 8

Posterior to pulmonary trunk, anterior to SVC

Clamped in surgery to stop arterial blood flow

Question 9

What happens if you have damage to the papillary muscles?

Answer 9

Valve incompetence and cardiac murmur

Question 10

Name 3 things that aid the valves?

Answer 10

Chordae tendinae “heart strings”, papillary muscles, cardiac fibrous skeleton

Question 11

What prevents electrical signals from being mixed between the atria and ventricles?

Answer 11

Fibrous Tissue

Question 12

Describe the structure of aortic/pulmonary valves

Answer 12

3 cusps: semilunar

*Diastole: backwards bloodflow fills up pockets, rapid ejection in systole pushes cusps against vessel wall

Question 13

Where does the L coronary supply

Answer 13

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)

Question 14

What can branch of the R coronary artery

Answer 14

PIVA: AV node, posterior 1/3 septum
*R dominant circulation (common)

SA node artery: node, both atria

Marginal artery: reaches apex

Question 15

Where does the bulk and the minority of cardiac venous drainage go through?

Answer 15

Bulk: coronary sinus

Minority: some independent anterior veins drain directly into R atria

Question 16

What are the direct openings in the heart wall that return venous drainage into heart chambers called?

Answer 16

venae cordis minimi

Question 17

Where should the apex of the heart be on a chest?

Answer 17

3.5 inches away from the sternum in 5th ICS

Question 18

Which intercostal spaces and heart chambers make up the bulk of the R and L sides of the heart?

Answer 18

L: 2-5 ICS, L ventricle
R: 3-6 ICS, R atria

Question 19

Where do you auscultate for each valve?

Answer 19

Mitral: 5th ICS, Left mid-clavicular

Tricuspid: 4th ICS, left sternal border

Pulmonary: L sternal edge, 2nd ICS

Aortic: R sternal edge, 2nd ICS

Question 20

What’s the name of the smooth wall part of R ventricle and what did it develop from?

Answer 20

Conus arteriosus, bulbus cordis

Question 21

Name which nerves give sympathetic and parasympathetic innervation to the heart, which is associated with referred cardiac pain?

Answer 21

Sympathetic: T1-T4 derived parts of sympathetic chain, visceral sensory fibres travel back to CNS with sympathetic nerves

Parasympathetic: VAGUS

Question 22

What does the fibrous pericardium bind to inferiorly?

Answer 22

Central diaphragmatic tendon

Question 23

What symptoms can result from decreased perfusion to the R coronary?

Answer 23

Arrhythmia, bradycardia

*supplies SA node

Question 24

Which vertebral level is a deep injury detrimental?

Answer 24

T4/T5 - 2nd costal cartilage