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Flashcards in Mediastinum Deck (81)
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Where is the superior mediastinum located?

between the superior thoracic aperture and the horizontal transverse thoracic plane

1

The SVC, brachiocephalic veins, arch of aorta, thoracic duct, trachea, esophagus, thymus, vagus nerves, left recurrent laryngeal nerve, and phrenic nerve are contained where?

superior mediastinum

2

Where is the inferior mediastinum?

between the transverse thoracic plane and the diaphragm

3

What is contained in the anterior mediastinum?

remnants of the thymus, lymph nodes, fat, and connective tissue

4

What is contained in the middle mediastinum?

heart, roots of the great vessels, arch of azygos vein, and main bronchi

5

What is contained in the posterior mediastinum?

esophagus, thoracic aorta, azygos vein, thoracic duct, vagus and splanchic nerves

6

Where is the anterior mediastinum?

between the body of the sternum and the transversus thoracis anteriorly and the pericardium posteriorly

7

What is the function of the pericardium?

encloses the heart and the roots of the great vessels

8

Where is the pericardial sac?

posterior to the body of the sternum and the 2nd to 6th costal cartilages at the level of T5-T8 vertebrae

9

What is the function of the fibrous pericardium?

protects the heart against sudden overfilling

10

What is the pericardial cavity?

space between the parietal and visceral layers of serous pericardium

11

The arterial supply of the pericardium is mainly from where?

pericardiacophrenic

12

The nerve supply of the pericardium is from where?

phrenic nerves (C3-C5), vagus nerves (CN X), and sympathetic trunks

13

Where is the apex of the heart located?

posterior to the left 5th intercostal space

14

What are the four surfaces of the heart?

anterior (sternocostal), diaphragmatic (inferior), left and right pulmonary surfaces

15

What are the four borders of the heart?

right (slightly convex), inferior (horizontal), left (oblique), and superior border

16

From where does the right atrium receive blood?

SVC, IVC, and coronary sinus

17

Where is the right auricle?

projects from the right atrium, overlapping the ascending aorta

18

Where is the opening of the coronary sinus?

between the right AV orifice and the IVC orifice in the posterior right atrium

19

The _____, separates the atria and has and oval depression, the _______.

interatrial septum; oval fossa

20

The right atrium has a rough, muscular wall composed of _______.

pectinate muscles

21

Where is the opening of the SVC?

superior right atrium, at level of right 3rd costal cartilage

22

Where is the opening of the IVC?

inferior right atrium, almost in line with SVC at level of 5th costal cartilage

23

What are the irregular muscular elevations in the right ventricle?

trabeculae carneae

24

What is the tricuspid valve?

guards the right AV orifice

25

What is the function of the chordae tendineae?

prevent separation of the valve cusps and their inversion during ventricular systole (prevents from being driven into right atrium)

26

What is the function of the papillary muscles?

begin to contract before contraction of the right ventricle, tightening the tendinous cords and drawing the cusps together

27

What is the interventricular septum?

strong, obliquely placed partition between the right and left ventricles

28

Where is the pulmonary valve?

at the apex of the conus arteriosus at the level of the left 3rd costal cartilage

29

What is the left auricle?

forms the superior part of the left border of the heart and overlaps the pulmonary trunk

30

What are the openings of the pulmonary veins?

right and left superior and inferior, entering the posterior wall of the left atrium

31

What is the mitral valve?

closes the orifice between the left atrium and left ventricle, and has two cusps

32

Where is the mitral valve located?

posterior to the sternum at the level of the 4th costal cartilage

33

Where is the aortic valve located?

posterior to the left side of the sternum at the level of the 3rd intercostal space

34

Where is the opening of the right coronary artery?

in the right aortic sinus

35

Where is the opening of the left coronary artery?

in the left aortic sinus

36

What are the branches of the RCA?

SA nodal, right marginal, posterior IV, and AV nodal

37

What are the branches of the LCA?

anterior IV, circumflex, and posterior IV

38

What is the origin of the left marginal artery?

circumflex branch of the LCA

39

What does the RCA supply?

right atrium, SA and AV nodes, and posterior part of IV septum

40

What does the right marginal artery supply?

right ventricle and apex of heart

41

What does the posterior IV artery supply?

right and left ventricles and posterior 1/3 of septum

42

What does the LCA supply?

most of left atrium and ventricle, IV septum, and AV bundles

43

What does the anterior IV artery supply?

right and left ventricles, anterior 2/3 of IV septum

44

What does the circumflex artery supply?

left atrium and left ventricle

45

What does the left marginal artery supply?

left ventricle

46

What does the posterior IV artery supply?

right and left posterior 1/3 of IV septum

47

What is the main vein of the heart?

coronary sinus

48

The coronary sinus receives the _____ at its left end and the ____ and ______ at its right end

great cardiac vein; middle and small cardiac veins

49

Where are the cardiac plexuses located?

anterior to the bifurcation of the trachea and posterior to the ascending aorta

50

From where is the sympathetic supply of the heart?

presynaptic fibers with cell bodies in the lateral horns of the superior 5 or 6 thoracic segments and postsynaptic sympathetic fibers with cell bodies in the cervical and superior thoracic paravertebral ganglia

51

From where is the parasympathetic supply of the heart?

presynaptic fibers of the vagus nerves (CN X)

52

From anterior to posterior, the contents of the superior mediastinum are:

thymus, great vessels (brachiocephalic V., superior SVC, bifurcation of pulm. trunk and roots of pulm. A., arch of aorta, vagus and phrenic N., cardiac plexus, left recurrent laryngeal N., trachea, esophagus, thoracic duct

53

What unites to form the SVC?

brachiocephalic veins, at the level of the 1st right costal cartilage

54

What is the function of the SVC?

returns blood from all structures superior to the diaphragm, except the lungs and heart

55

Where is the SVC located?

right side of superior mediastinum, anterolateral to the trachea and posterolateral to the ascending aorta; ends at level of 3rd costal cartilage and enters right atrium

56

Where is the right phrenic nerve?

between the SVC and the mediastinal pleura

57

Where is the ligamentum arteriosum?

passes from the root of the left pulmonary artery to the inferior surface of the arch of aorta

58

Where is the left recurrent laryngeal nerve?

hooks beneath the arch immediately lateral to the ligamentum arteriosum and then ascends between the trachea and esophagus

59

What is the origin of the vagus nerve?

8-10 rootlets from medulla of brainstem

60

What is the origin of the phrenic nerve?

anterior rami of C3-C5 nerves

61

What is the origin of the intercostal nerves (1-11)?

anterior rami of T1-T11 nerves

62

What is the origin of the subcostal nerve?

anterior ramus of T12 nerve

63

What is the origin of the recurrent laryngeal nerve?

vagus nerve

64

What is the origin of the cardiac plexus?

cervical and cardiac branches of vagus nerve and sympathetic trunk

65

What is the origin of the pulmonary plexus?

vagus nerve and sympathetic trunk

66

What is the origin of the esophageal plexus?

vagus nerve, sympathetic ganglia, and greater splanchic nerve

67

What does the vagus nerve innervate?

pulmonary plexus, esophageal plexus, and cardiac plexus

68

What does the phrenic nerve innervate?

central portion of diaphragm

69

What do the intercostals innervate?

muscles in and skin over intercostal space; lower nerves innervate muscles and skin of anterolateral abdominal wall

70

What does the subcostal nerve innervate?

abdominal wall and skin of gluteal region

71

What does the recurrent laryngeal nerve innervate?

intrinsic muscles of larynx (except cricothyroid); sensory inferior to level of vocal cords

72

What does the cardiac plexus innervate?

impulses pass to SA node; parasympathetic fibers slow rate, reduce force of heartbeat, and constrict coronary arteries; sympathetic fibers have opposite effect

73

What does the pulmonary plexus innervate?

parasympathetic fibers constrict bronchioles; sympathetic fibers dilate them; afferents convey reflexes

74

What does the esophageal plexus innervate?

vagal and sympathetic fibers to smooth muscle and glands of inferior 2/3 of esophagus

75

What is the origin of the ascending aorta?

aortic orifice of left ventricle

76

What is the origin of the arch of aorta?

continuation of ascending aorta

77

What is the origin of the thoracic aorta?

continuation of arch of aorta

78

What are the branches of the ascending aorta?

right and left coronary arteries

79

What are the branches of the arch of aorta?

brachiocephalic, left common carotid, left subclavian

80

What are the branches of the thoracic aorta?

posterior intercostal arteries, subcostal, some phrenic arteries, and visceral branches