Anatomy - Heart and Great Vessels Flashcards
What joins to form the superior vena cava?
Right and left brachiocephalic veins
What is each brachiocephalic vein formed by?
Union of internal jugular vein and subclavian vein
What does the superior vena cava empty into?
Right atrium
What does the internal jugular vein drain?
Head and neck (correlates to carotid artery)
What does the subclavian vein drain?
Upper limbs
What is the connection between the pulmonary trunk and aortic arch called in adults?
Closed structure –> ligamentum arteriosum
What is the ‘ligamentum arteriosum’ in foetal development?
Duct that allows blood to pass from pulmonary trunk into arch of aorta (bypassing lungs)
What does the pulmonary trunk divide into?
Right and left pulmonary arteries
Where does left vagus nerve pass?
Around arch of aorta
Where does the left phrenic nerve pass?
Adheres to lateral surface of pericardium and supplies diaphragm
What is the base of the heart formed by?
right and left atria
What is the apex of the heart formed by?
Predominantly by the left ventricle
What are the 2 pericardial sinuses?
- Transverse
- Oblique
What is the transverse pericardial sinus?
Passage between left and right (arterial and venous) parts of pericardial space. Behind the aorta and pulmonary artery and anterior to superior vena cava
What is clinical importanceof transverse pericardial sinus?
Used in cardiac bypass surgery. Passing one end of clamp through sinus, and other end anterior to aorta/pulmonary trunk will allow complete blockage of blood output. Isolates pulmonary trunk and ascending aorta. Complete blockage and gather deoxygenated blood (that would usually go to lung).
Where is oblique pericardial sinus?
Lies behind left atrium and in between left and right pulmonary veins
What are the aortic sinuses (left and right)
Dilations of the ascending aorta which occur just above aortic valve. These widenings are between the wall of the aorta and each of the three cusps of the aortic valve.
Where do the left and right coronary artery arise from?
Ascending aorta from left and right aortic sinuses
What does the LCA initially branch into?
- Anterior interventricular artery (or left anterior descending artery)
- Left circumflex artery
What does the left circumflex artery then branch into?
Left marginal branch
What does RCA branch into?
- Right marginal artery (anteriorly)
- Posterior interventricular artery (right posterior descending artery)
What emerges from the pulmonary trunk?
Left and right pulmonary artery
What are the coronary veins?
Return deoxygenated blood from the myocardium back to the right atrium
What do the vast majority of coronary veins drain into?
Coronary sinus which then empties deoxy blood into the right atrium
What are plexuses?
A network of nerves or vessels in the body –> nerves give branches that intermingle together to form a plexus of nerves
What are the plexuses in the thorax supplied with fibres from?
- Branches from sympathetic chain
- Branches from vagus nerve
Where does vagus nerve descend from?
Brainstem and continues posterior to root of lung
Why are plexuses ‘autonomic’?
Sympathetic and parasympathetic input
What provides sympathetic imput to plexuses?
Sympathetic chain
What provides parasympathetic input to plexuses?
Vagus nerve
What are the right and left recurrent laryngeal nerves?
Branch of the vagus nerve that supplies all the intrinsic muscles of the larynx (with exception of cricothyroid muscles)
Where does the left recurrent laryngeal nerve pass?
Underneath the arch of the aorta to ascend and supply the larynx
Where does the right recurrent laryngeal nerve pass?
No aortic arch so vagus fgives off recurrent laryngeal which loops underneath the brachiocephalic artery which then ascends towards the larynx
Diagram of nerves
Where is the root of the lung?
Located at the hilum of each lung, just above the middle of the mediastinal surface and behind the cardiac impression of the lung. It is nearer to the back (posterior border) than the front (anterior border). The root of the lung is connected by the structures that form it to the heart and the trachea
Where does vagus nerve pass in relation to root of lung?
Posterior
Where does phrenic nerve pass in relation to root of lung?
Anterior
What do dilations in sympathetic chain contain?
Cell bodies of nerves
What are the 3 major branches from the arch of the aorta?
- Branchiocephalic trunk (artery)
- Left common carotid artery
- Left subclavian artery
What does brachiocephalic trunk/artery then branch into?
Right common carotid artery and right subclavian artery
What is the interal thoracic artery a branch of?
Subclavian artery
What is the azygos vein?
Vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cava. It connects the systems of superior vena cava and inferior vena cava and can provide an alternative path for blood to the right atrium when either of the venae cavae is blocked
Transports deoxygenated blood from the posterior walls of the thorax and abdomen into the superior vena cava vein.
What does azygos system drain?
Thoracic cage/wall
Where does azygos vein pass in relation to root of lung?
Loops over root of lung
