Lecture 19: Middle Mediastinum Flashcards Preview

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Flashcards in Lecture 19: Middle Mediastinum Deck (94):
1

Contents of the middle mediastinum

pericardium (the envelops phrenic nerves, heart, root of aorta, distal segment of the superior vena cava, pulmonary veins, inferior vena cava, pulmonary trunk, right pulmonary arteries, and right and left main stem bronchi)

2

What are the components of pericardium

Visceral and partietal pericardium create the pericardial cavity contains serous fluid- derived from intraembryonic coelomic space

3

Pericarditis

inflammation of the pericardial sac- can result in fluid accumulation in pericardial cavity which impedes the motion of the heart. Procedure to remove fluid is pericardiocentesis

4

Cardiac tamponade

The accumulation of fluid in the pericardial cavity that impedes the motion of the heart caused by inflammation of the pericardial sac

5

What are the two pericardial sinuses

oblique and tranverse

6

Transverse sinus

connects the right and left sides of the cavity, and separates the outflow tracts (aorta and pulmonary trunk) from the inflow tract (superior vena cava)

7

Oblique sinus

Inverted U-shaped on the dorsal to the left atrium between the pulmonary veins and superior vena cava

8

Clinical significance of these sinuses?

??

9

Are the right and left sides of the heart on the left and right sides of the thorax

no

10

What is the orientation of the heart after rotation during development

right ventricle is anterior and positioned to the left along with the left ventricle

11

What region of the heart comprises the base?

the posterior aspect

12

What region comprises the apex of the heart

left ventricle (the inferiolateral tip)

13

Where is the apex of the heart normally positioned?

5th intercostal space

14

Coronary sulcus

encircles the heart and discerns between the atrium and ventricles

15

Interventricular sulci

separates the two ventricles (one on the anterior and posterior)

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Anterior surface of the heart

mainly right ventricle with a little right atrium

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Posterior surface of heart

Left atrium with smaller portions of the left ventrical and right atrium

18

Diaphragmatic surface of hear

mostly right ventricle with a little contribution by the left ventricle

19

Superior boarder of heart

roots of aorta, pulmonary a., and superior vena cava

20

Where are the strongest heart sounds and why

left to the sternum because the heart is usually slightly left of the midline

21

Dextrocardia

when the heart is slightly right to the midline instead of left and results in the strongest heart sounds being to the right of the sternum

22

How does some endocardial tissues receive nourishment

via direct diffusion of oxygen and nutrients from blood within the cardiac chambers

23

Where do the coronary arteries and veins travel

beneath the epicardium (visceral peritoneum embedded in fat

24

What aortic sinus is the right coronary artery originated in?

right aortic sinus (of Valsalva)

25

What does the right coronary a. supply

Right atrium, right ventricle, and SA node

26

What are two important branches given off by the right coronary a.

nodal a. (posterior to right auricle) and right marginal a. (descending right cardiac border)

27

What does the left coronary a. supply

much of the left ventricle, small part of right ventricle, ventricular septum, and part of the left atrium

28

Where does the left coronary a course

arises from aorta and passes posterior to pulmonary trunk

29

Where does the left coronary a. branch

coronary sinus

30

What are the two branches of the left coronary a.

left anterioventricular branch and circumflex blanch

31

What gives rise to the left marginal a.

the circumflex artery

32

Where does the circumflex a. travel

in the coronary sulcus

33

What is the inter ventricular septum primarily supplied by?

branches of the left coronary a.

34

What does the nodal branch supply

right atrium and SA node (sin-atrial node)

35

What does the right marginal a. supply?

Anterior wall of the right ventricle

36

What does the posterior inter ventricular a. supply?

Posterior wall of the right ventricle and the posterior part of the inter ventricular septum

37

What does the anterior inter ventricular a supply?

anterior left ventricle, most of the anterior inter ventricular septum, apex

38

What does the left marginal a. supply?

Lateral wall of the left ventricle

39

What does the circumflex branch supply?

Posterior wall of the left atrium and left ventricle

40

Describe how we know if a heart is right dominant

The posterior inter ventricular a is derived from the right coronary a. and the right coronary crosses to the left side to supply the left ventricularwal and posterior inter ventricular septum.

41

Left commence?

Posterior interventricular a. derived from the left coronary a.

42

Codominence? ***

coronary arteries are balance?

43

ischemia (minor)

insufficicent coronary blood flow, leads to angina pectoris (chest pain)

44

ischemia (major)

dysrhythmias or cardiac arrest

45

cause of ischemia

arteriosclerosis

46

What are the two systems used for venous drainage of the heart

cardiac veins and thebesians veins

47

Great cardiac v. location

begins at the cardiac apex, follows the anterior inter ventricular sulcus to the base of the ventricles then passes to the left in the coronary sinus

48

What does the great cardiac v. drain

Left artrium and both ventricles

49

Middle cardiac v. location

starts at the cardiac apex rises in the posterior inter ventricular sulcus and ends in the coronary sinus

50

What does the middle cardiac v. drain

posterior ventricular surface

51

Anterior cardiac v. locations

span the anterioventricular groove and drain directly into the right atrium

52

What does the Anterior cardiac v. drain

from the upper surface of the right ventricle

53

thebesian veins location

begin in the myocardium and empty into the cardia atria or ventricles.

54

What empties into the right atrium

superior and inferior vena cava

55

crista terminalis

raised ridge on the inner arterial wall that demarcates its anterior and posterior segments

56

Where is the SA node found?

where the crust terminals meets the perimeter of the superior vena cava oriface

57

Inforeior vena cava valve

semi-lumar shaped tissue

58

Fossa ovalis location- embryonic remenent

septal wall of right atrium- site of fetal foramen ovale

59

Valve of coronary sinus is what shape?

crescent shaped

60

What are the 3 leaflets of the tricuspid valves

Anterior, Posterior, and Septal

61

Position of the anterior and posterior leaflets

Anterior-Superior
Posterior- Inferior

62

Purpose of chord tendinae

the tether the leaflets to the ventricular wall and help keep the valve leaflets closely approximated during systole(when pressures within the ventricular chambers are highest) this prevents blood from leaking from the ventricle back into the arterial chamber

63

What two papillary muscles does the posterior ventricle have

anterior and posterior

64

Where does the moderator band pass?

Passes from the inferior portion of the septal wall to the base of the anterior papillary muscles.

65

What are the 3 cusps of the pulmonary valve

anterior left and right

66

What does the pulmonary trunk branch into

right and left pulmonary arteries

67

Ligamentum arteriosum

connects the pulmonary trunk to the ascending aorta. Remnant of ductus arteriosus

68

What lung will the right pulmonary artery go to

right

69

Are the pulmonary arteries posterior or anterior to the mainstream bronchi?

Anterior

70

What are the branches of the right/left pulmonary a

Upper and lower (to supply their respective lobes)

71

Position of the anterior and posterior leaflets of the mitral valve

Superior and inferior respectively

72

Mitral vale

Connects the left atrium to left ventricle and is a bicuspid valve

73

How many cusps does the aortic valve have and what are they called?

3- called right and left coronary cusp and non-coronary cusp

74

What are aortic sinuses of Valsalva

3 small dialations called the right and left coronary and non-coronary

75

Where are the chemoreceptors located in the heart and what do they do?

Located in the wall of the ascending aorta they monitor pH and CO2 in the blood.

76

Why are the sounds of valves hear at a site distant from their location

because anatomically they lie close to one another and and posterior to the sternum

77

Where is the aortic valve heard?

right 2nd intercostal space

78

Where is the pulmonic valve heard?

Left second intercostal space

79

Where is the mitral valve heard?

left 5th intercostal space at midclavicular line

80

Where is the tricuspid valve heard?

to the left of the xiphosternal junction

81

What does the cardiac cycle consist of

diastole and systole

82

diastole

ventricular filling

83

systole

ventricular emptying

84

Diastole begins with...

the closure of the aortic and pulmonic valves. Blood now flows from the right atrium across the tricuspid valve to the right ventricle and from the left atrium across the mitral valve into the left ventricle

85

Systole begins when...

When the ventricles are full. The ventricular muscles begin to contract which forces the tricuspid valves of the aorta and pulmonary trunk to open

86

Lub sound of hear

caused by the vibration of blood in the ventricular chambers as systole begins and the atrioventricular (A-V) valves shut

87

dub sound of heart

caused by vibration of blood from the closure of the aortic and pulmonary valves at the end of systole

88

What is the pacemaker of the heart

SA node (At the junction of crust terminalis and superior vena cava in right atrium)

89

Where is the atrioventricular node (AV) located?

near the base of the intertribal septum along opening of coronary sinus

90

Where does the atrioventricular bundle of his run and divide into?

The atrioventricular bundle of his exits the AV node and travels in the inter ventricular septum where it divides into right and left bundle branches

91

Right bundle branch (traveling distance)

travels inferiorly in the septum to enter the moderator band and terminate in the base of the anterior papillary muscle of the left ventricle

92

Left bundle branch

Also courses in the inter ventricular septum which terminates in the base of each papillary muscle of the left ventricle

93

Both the heath receive sympathetic or parasympathetic innervation

both- also receives visceral sensory nerves

94

Where are the sympathetic ganglion that innervate the heart located

Spinal cord segments T1-T6