heart and great vessels Flashcards
great vessels: describe the course of the great arteries (ascending aorta, the arch of the aorta and descending thoracic aorta) and great veins (inferior and superior vena cavae) and the azygos venous system; list their major branches/tributaries and the structures they supply/drain
what is the purpose of the thoracic duct
lymphatic drainage
contents (8) of superior mediastinum from anterior to posterior
thymus, phrenic nerves, great veins, main lymphatic trunks, vagus nerve, great arteries, trachea and main bronchi, upper oesophagus
what are the two great veins
inferior vena cavae, superior vena cavae
what does the superior vena cava enter and from where
right atrium from above, to right of aorta
what does the inferior vena cava enter, from where and through what
right atrium from below through central tendon of diaphragm at T8 (where heart sits)
what is the superior vena cava formed by
asymmetric union of right and left brachiocephalic veins (left crosses to join right)
what does each brachiocephalic vein (arm and head) form from
an internal jugular vein and a subclavian vein
what tributaries form left and right brachiocephalic veins and from where
internal jugular vein (from head) and subclavian veins (from upper limbs)
where does the left brachiocephalic vein cross to join right brachiocephalic vein
crosses posterior to and to the right of manubrium (sternum)
what is the function of the azygos vein
drain posterior wall of thorax and abdomen into superior vena cava
what does the azygos vein arch over
right lung root (asymmetric as right is more prominent)
what are the 3 great arteries of the superior mediastinum
ascending aorta, aortic arch, descending thoracic aorta (T12)
what are the 2 branches of the ascending aorta
right and left coronary arteries (first as supply heart with most richly oxygenated blood; end arteries)
what are the 3 branches of the aortic arch
brachiocephalic trunk, left common carotid artery, left subclavian artery
what does the brachiocephalic trunk divide into
right common carotid and right subclavian arteries
where does the aortic arch arise in relation to the trachea
anteriorly
what does the aortic arch arch over
left main bronchus at lung root
what arteries does the trachea lie behind and between
brachiocephalic and left common carotid arteries
what are common carotid arteries divided into and where
external and internal carotids high in neck
what is the function of the carotid arteries
supply head (face and brain) and neck
what arteries do the vertebral arteries (neck) come from
subclavian arteries
arteries of oesophagus
intercostal spaces at top have different supply to bottom (aorta doesn’t ascend as high as ICS 1 and 2 - posterior intercostal arteries receive supply from subclavian arteries - supreme intercostal artery); others supplied by descending aorta
azygos
thoracic duct; left and right brachioceophalic merge to form SVC; left to right side, ascends and drains into SVC; azygos smaller than aorta; on left: accessory hemiazygos and hemiazygos
azygos venous system
variable; drains posterior wall of chest, upper abdomen and posterior mediastinal organs; usually accessory hemiazygos (upper) and hemiazygos (lower) veins on left cross thoracic vertebral bodies to join single axygos vein on right; azygos vein arches over right lung root to enter SVC just above right atrium
thoracic duct
lymph duct returning lymph from lower limbs, pelvis, abdomen & left thoracic wall to blood; begins below diaphragm at cisterna chyli; starts between oesophagus and aorta on right, runs along spinal column; crosses behind oesophagus to left side between T7 and T4; drains into junction of left subclavian and left internal jugular veins (to form left brachiocephalic vein)
levels of IVC, oesophagus, descending aorta structure into diaphragm
T8, 10, 12
