Gross Anatomy Mediastinum (Posterior And Superior)

Front 1

in what is all of the thoracic viscera contained, with the exception of the lungs?

Back 1

mediastinum

Front 2

a line between what two points divides the mediastinum into superior and inferior mediastina?

Back 2

sternal angle (of Louis)

intervertebral disc between T4 and T5

Front 3

what are the subdivisions of the inferior mediastinum?

Back 3

anterior - fatty and thymic tissues
middle - heart and great vessels
posterior - viscera traversing thorax (to abdomen)

Front 4

from where is the thymus derived?

Back 4

third pharyngeal pouch

Front 5

from where are the inferior parathyroid glands derived?

Back 5

third pharyngeal pouch

Front 6

where is the thymus?

Back 6

retrosternal
between two costomediastinal recesses
anterior to left brachiocephalic vein and aortic arch

Front 7

what forms the left brachiocephalic vein?

Back 7

left internal jugular vein
left subclavian vein

posterior to left sternoclavicular joint

Front 8

what forms the superior vena cava?

Back 8

right brachiocephalic vein
left brachiocephalic vein

at 1st right intercostal space

Front 9

in relationship to the three great branches of the aortic arch, where does the left brachiocephalic vein pass?

Back 9

anterior and superior to the three great branches

Front 10

what forms the right brachiocephalic vein?

Back 10

right internal jugular vein
right subclavian vein

posterior to right sternoclavicular joint

Front 11

where does the superior vena cava enter the right atrium?

Back 11

3rd right costal cartilage

Front 12

where does the arch of the azygos system empty?

Back 12

posterior surface of the superior vena cava

Front 13

with what does the right phrenic nerve run?

Back 13

superior vena cava

Front 14

posterior to what does the esophagus lie?

Back 14

trachea

Front 15

where does the trachea begin?

Back 15

below larynx
below cricoid cartilage
at C6

Front 16

what is the bifurcation of the trachea?

Back 16

carina (at level of T4/5)

Front 17

what is to the right of the trachea?

Back 17

brachiocephalic artery
right vagus
azygos arch

Front 18

what is to the left of the trachea?

Back 18

left common carotid artery
left subclavian artery
left vagus nerve
left recurrent laryngeal nerve

Front 19

where are lymph nodes found on the trachea? where do they drain?

Back 19

all three bifurcation angles

drain into right lymphatic duct and thoracic duct

Front 20

in relation to the trachea, where is the cardiac plexus?

Back 20

anterior to the bifurcation of the trachea

also inferior to bifurcation of pulmonary trunk and arch of aorta

Front 21

what are the extensions of the cardiac plexus?

Back 21

right and left pulmonary plexus
plexus of the thoracic aorta

Front 22

where do the preganglionic sympathetic nerves from the cardiac plexus originate?

Back 22

T1-T4 lateral horn of spinal cord

Front 23

through what do the preganglionic sympathetic nerves enter the paravertebral sympathetic chain of ganglia?

Back 23

white rami communicantes

Front 24

where do the sympathetic nerves to the cardiac plexus synapse?

Back 24

upper thoracic ganglia
cervical ganglia

Front 25

what is the effect of sympathetic nerves on the heart?

Back 25

tachycardia
vasodilation of coronary arteries

Front 26

where are the cell bodies of the visceral sensory fibers of the heart?

Back 26

dorsal root ganglion, axons entering spinal cord at T1-T2

Front 27

from where does the vagus nerve arise?

Back 27

cell bodies in the brainstem

Front 28

what is the effect of parasympathetic innervation of the heart?

Back 28

bradycardia

Front 29

what is the purpose of afferent vagal fibers from the heart?
efferent vagal fibers?

Back 29

afferent - chemo- and baroreception
efferent - induce bradycardia

Front 30

where are the cell bodies for the afferent vagal fibers from the heart, aorta and great vessels?

Back 30

inferior ganglion of the vagus nerve

Front 31

where does the inferior aspect of the aortic arch lie?

Back 31

on a line from sternal angle through the T4/5 intervertebral disc

Front 32

where does the arch of the aorta become the descending aorta?

Back 32

to the left of the T5 vertebral body

Front 33

from where do the branches arise from the arch of the aorta?

Back 33

superior aspect

Front 34

what are the branches of the arch of the aorta?

Back 34

from right to left, brachiocephalic trunk, left common carotid artery, left subclavian artery

Front 35

into what does the brachiocephalic trunk divide?

Back 35

right subclavian artery
right common carotid artery

posterior to right sternoclavicular joint

Front 36

what is the ligamentum arteriosum?

Back 36

vestige of the ductus arteriosus, which shunted blood from the pulmonary system during prenatal life

Front 37

what does the left recurrent laryngeal nerve loop around?

Back 37

ligamentum arteriosum and arch of aorta

Front 38

between what two structures do both recurrent laryngeal nerves ascend into the neck?

Back 38

trachea
esophagus

Front 39

around what does the right recurrent laryngeal nerve loop?

Back 39

right subclavian artery

Front 40

with what is the right phrenic nerve associated?

Back 40

upper course - SVC
pierces diaphragm with IVC

Front 41

where do the phrenic nerves pierce the diaphragm?

Back 41

right phrenic nerve - IVC
left phrenic nerve - margin of fibrous pericardial attachment to the central tendon

Front 42

through what does the descending aorta pass into the abdomen?

Back 42

aortic hiatus at T11/12, through the diaphragm

Front 43

with what do the greater splanchnic nerves from the sympathetic trunk join and enter the abdomen?

Back 43

descending aorta

Front 44

what are the visceral branches of the descending aorta?

Back 44

1-3 bronchial arteries
1-3 esophageal arteries
branches to pericardium and diaphragm

Front 45

what are the parietal branches of the descending aorta?

Back 45

right and left posterior intercostal arteries (3rd intercostal space to below rib 12)

Front 46

where does the thoracic duct begin?

Back 46

cisternal chyli (a series of lymph sacs), posterior to abdominal aorta, inferior to diaphragm

Front 47

through what does the thoracic duct enter the thorax?

Back 47

aortic hiatus, posterior to descending aorta

Front 48

on which side of the vertebral column does the thoracic duct lie?

Back 48

right side

Front 49

where does the thoracic duct end?

Back 49

at the junction between the left subclavian and left internal jugular veins

Front 50

from what areas does the thoracic duct NOT drain lymph?

Back 50

right thorax
right upper limb
right side of head and neck

(all other areas use thoracic duct)

Front 51

into where does the right lymphatic duct drain?

Back 51

junction of right internal jugular vein and right subclavian vein

Front 52

what is drained by the hemiazygos vein?

Back 52

posterior intercostal veins on left side of body

Front 53

where does the hemiazygos vein join with the azygos vein?

Back 53

mid-thorax
(hemiazygos vein passes anterior to the vertebral column)

Front 54

where does the azygos vein drain?

Back 54

posterior aspect of superior vena cava at level of costal cartilage of rib 3

Front 55

what does the right superior intercostal vein drain?

Back 55

second, third, fourth right intercostal spaces

Front 56

into what does the right superior intercostal vein drain?

Back 56

azygos vein

Front 57

into what does the left superior intercostal vein drain?

Back 57

left brachiocephalic vein
(crosses over anterior aspect of aortic arch first)

Front 58

what is drained by the highest posterior intercostal veins?

Back 58

first intercostal space on each side

Front 59

into what do the highest posterior intercostal veins drain?

Back 59

brachiocephalic veins

Front 60

where do the anterior intercostal veins drain?

Back 60

internal thoracic veins, which empty into the subclavian veins

Front 61

on which side of the diaphragm does the esophagus pierce it?

Back 61

left dome at T10 (rib 7 costocartilage)

Front 62

in what four regions is the esophagus constricted?

Back 62

C6 - upper esophageal sphincter - voluntary (15*)
T2/3 - crossing of the aortic arch (22*)
T4/5 - crossing of left primary bronchus (27*)
T10 - diaphragm (40*)

*-distance from the incisor teeth

Front 63

what is the superior esophageal sphincter?

Back 63

cricopharyngeus - a voluntary muscle

Front 64

what innervates the inferior esophageal sphincter?

Back 64

vagus nerve - parasympathetic - opens
sympathetic fibers - close

Front 65

inferior to the root of the lung, which vagus nerve lies anterior to the esophagus? which lies posterior?

Back 65

anterior - left vagus nerve
posterior - right vagus nerve

Front 66

what forms the anterior and posterior esophageal plexuses?

Back 66

anterior - left vagus nerve
posterior - right vagus nerve

Front 67

where do the fibers from the vagus nerves pierce the diaphragm?

Back 67

through esophageal hiatus

(as single nerves derived from the anterior and posterior esophageal plexuses)

Front 68

what are the vagus nerves renamed below the diaphragm?

Back 68

left vagus nerve - anterior gastric nerve
right vagus nerve - posterior gastric nerve

Front 69

what is the action of the vagus nerve on the esophagus?

Back 69

induce peristalsis

(secretomotor to mucous glands)