heart and great vessels

Question 1

what is the purpose of the thoracic duct

Answer 1

lymphatic drainage

Question 2

contents (8) of superior mediastinum from anterior to posterior

Answer 2

thymus, phrenic nerves, great veins, main lymphatic trunks, vagus nerve, great arteries, trachea and main bronchi, upper oesophagus

Question 3

what are the two great veins

Answer 3

inferior vena cavae, superior vena cavae

Question 4

what does the superior vena cava enter and from where

Answer 4

right atrium from above, to right of aorta

Question 5

what does the inferior vena cava enter, from where and through what

Answer 5

right atrium from below through central tendon of diaphragm at T8 (where heart sits)

Question 6

what is the superior vena cava formed by

Answer 6

asymmetric union of right and left brachiocephalic veins (left crosses to join right)

Question 7

what does each brachiocephalic vein (arm and head) form from

Answer 7

an internal jugular vein and a subclavian vein

Question 8

what tributaries form left and right brachiocephalic veins and from where

Answer 8

internal jugular vein (from head) and subclavian veins (from upper limbs)

Question 9

where does the left brachiocephalic vein cross to join right brachiocephalic vein

Answer 9

crosses posterior to and to the right of manubrium (sternum)

Question 10

what is the function of the azygos vein

Answer 10

drain posterior wall of thorax and abdomen into superior vena cava

Question 11

what does the azygos vein arch over

Answer 11

right lung root (asymmetric as right is more prominent)

Question 12

what are the 3 great arteries of the superior mediastinum

Answer 12

ascending aorta, aortic arch, descending thoracic aorta (T12)

Question 13

what are the 2 branches of the ascending aorta

Answer 13

right and left coronary arteries (first as supply heart with most richly oxygenated blood; end arteries)

Question 14

what are the 3 branches of the aortic arch

Answer 14

brachiocephalic trunk, left common carotid artery, left subclavian artery

Question 15

what does the brachiocephalic trunk divide into

Answer 15

right common carotid and right subclavian arteries

Question 16

where does the aortic arch arise in relation to the trachea

Answer 16

anteriorly

Question 17

what does the aortic arch arch over

Answer 17

left main bronchus at lung root

Question 18

what arteries does the trachea lie behind and between

Answer 18

brachiocephalic and left common carotid arteries

Question 19

what are common carotid arteries divided into and where

Answer 19

external and internal carotids high in neck

Question 20

what is the function of the carotid arteries

Answer 20

supply head (face and brain) and neck

Question 21

what arteries do the vertebral arteries (neck) come from

Answer 21

subclavian arteries

Question 22

arteries of oesophagus

Answer 22

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

Question 23

azygos

Answer 23

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

Question 24

azygos venous system

Answer 24

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

Question 25

thoracic duct

Answer 25

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)

Question 26

levels of IVC, oesophagus, descending aorta structure into diaphragm

Answer 26

T8, 10, 12