Block 2; Week 1; Sievert; Heart & Mediastinum Flashcards

1
Q

What is the landmark that separates the superior mediastinum from the inferior mediastinum?

A

the sternal angle (separates the manubrium from the sternum).

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2
Q

What is the transverse thoracic plane?

A

It separates the superior & inferior mediastinum. Its anterior portion is the sternal angle. Its posterior portion is at the level of the T4 & T5 vertebrae.

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3
Q

What are all of the subdivisions of the mediastinum & where is the heart/perciardial sac found?

A

Superior & Inferior (anterior, middle, posterior).

The pericardial sac/heart is found in the inferior middle portion of the mediastinum.

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4
Q

What is the serous pericardium made up of? Where is it found? What are its 2 layers?

A

Mesothelium (simple squamous).

Found near the heart. Parietal layer on the inside of the fibrous pericardium. Visceral layer found on top of the heart.

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5
Q

What are the functions of the fibrous pericardium?

A

Anchors the heart to the diaphragm b/c it is continuous w/ the central tendon of the diaphragm.

B/c it is unyielding it prevents overfilling.

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6
Q

What are the great vessels?

A

Superior & Inferior Vena Cava

Aorta

Pulmonary trunk–>pulmonary arteries

Pulmonary veins

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7
Q

T/F The blood being pumped b/w both the sides of the heart needs to be approximately equal in volume.

A

True!!

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8
Q

What phase does the cardiac cycle begin with?

A

Diastole.

It ends in systole.

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9
Q

Which valves close & which valves open during diastole? What contracts?

A

Aortic & Pulmonic valves close.

Mitral & Tricuspid valves open.

It is a filling phase.

At the end of the phase: atria contraction takes place.

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10
Q

Which valves close & which valves open during systole?

A

Mitral & tricuspid valves close during systole.

The aortic & pulmonic valves open during systole.

This is a period of ventricular emptying.

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11
Q

What can happen if the blood on both sides of the heart is not balanced/equal?

A

Buildup of blood somewhere-often edema.

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12
Q

Where is the cardiac notch located?

A

On the left lung. Exposes the heart to the undersurface of the sternum.

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13
Q

Sometimes you may need to drain fluid from the heart or the pericardial sac–like with cardiac tamponade. Would the cardiac notch be a good place to insert the needle?

A

No. B/c even tho the left lung isn’t there…the pleural sac is & it could introduce air or fluid into the pleural sac, which could be dangerous.

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14
Q

Where is the mediastinum located?

A

Between the 2 pulmoanry cavities.

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15
Q

Are the 2 pulmonary cavities attached?

A

No. They are separate. This is why they can be moved aside to access the pericardial sac.

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16
Q

Which part of the pericardium fuses with the diaphragm?

A

The fibrous layer of the pericardium (outer layer) fuses with the central tendon of the diaphragm.

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17
Q

What is the vertebral level that corresponds to where the diaphragm meets the pericardium?

A

T9 vertebral level.

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18
Q

All of our discussion of mediastinum & its borders & its structures is dependent on the patient being in what position?

If the patient were to stand up–>what might happen to the aortic arch?

A

Supine position important!

Aortic arch might go from being in the superior mediastinum to the inferior mediastinum.

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19
Q

What are some significant things about the level of the T9 vertebrae?

A

This is the level of the diaphragm.

This is the level where the fibrous pericardium fuses with the central tendon of the diaphragm.

As the middle mediastinum houses the pericardium…this is necessarily the lower border of the inferior mediastinum.

This is also the area of the xiphosternal junction.

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20
Q

What are some things that can be found in the superior mediastinum?

A

esophagus; trachea

vagus; phrenic; cardiac nerves

aortic arch; parts of the great vessels

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21
Q

What are the 3 things that the inferior mediastinum can be broken down to? What structures are in each?

A

Anterior: fat, thymus in kids, branches of internal thoracic artery

Middle: pericardium–>heart, SVC, ascending aorta

Posterior: stuff in front of the vertebrae–vessels, nerves, structures.

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22
Q

Which part of the pericardium makes it on to parts of the great vessels? Which vessels? We’re talking w/i the middle mediastinum.

A

The parietal layer of the serous membrane (inner part of the fibrous pericardium) is also on parts of the SVC base & pulmonary trunk & aorta.

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23
Q

The phrenic nerves & pericardiacophrenic arteries & veins are considered for the purposes of the course a part of which section of the mediastinum?

A

The middle mediastinum. Disagreement is b/c they are outside of the pericardial sac. But they are in b/w the 2 pulmonary cavities.

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24
Q

What does the phrenic nerves & pericardiacophrenic arteries & veins supply?

A

The fibrous portion of the pericardium & the parietal layer of the serous pericardium.

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25
Q

How is invagination related to the pericardial sac?

A

The heart pushes thru this serous pericardium, causing invagination. You get 2 layers of serous pericardium surrounding the heart. Layer closest to the heart: visceral. Other layer: parietal (fused w/ the fibrous layer).

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26
Q

What is the serous pericardium made out of? What tissue is the fibrous pericardium made out of ?

A

Serous pericardium: mesothelium

Fibrous pericardium: CT

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27
Q

What is another name for the visceral serous pericardium?

A

Epicardium.

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28
Q

Is the fibrous pericardium distensible?

Is the serous pericardium distensible?

A

Fibrous-NO

serous-YES

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29
Q

What is the space b/w the visceral & parietal layers of serous pericardium called?

What is it called when fluid builds up there?

A

Pericardial cavity.

Cardiac Tamponade.

*dangerous b/c w/ each beat of the heart–less & less fluid can be pumped out of the heart. & more & more leaks into cavity.

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30
Q

If you are doing open heart surgery, what do you want to make sure you don’t cut??

A

The phrenic nerve!! It runs alongside the pericardial sac.

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31
Q

Where does the phrenic nerve originate?

A

As a part of the ventral rami of a spinal nerve.

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32
Q

What would a right–left side shunt do? What age of person would this be important in?

What is an important R–>L shunt example?

A

Would bypass pulmonary circulation, bypass the lung.

Important in fetal development.

Ductus Arteriosis. Snags the left recurrent laryngeal nerve.

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33
Q

What does the ductus arteriosis become & when? What does it do?

A

Ductus arteriosis becomes the ligamentum arteriosum at birth. It is a R–>L shunt from the pulmonary trunk to the arch of the aorta. Snags the left recurrent laryngeal branch.

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34
Q

What is the transverse sinus?

A

It is the space that you can stick your finger thru that is b/w the outflow vessels & the inflow vessels of the heart.

The outflow vessels are anterior to the sinus & the inflow structures are posterior to the sinus.

Embryologically: Formed b/c of the folding of the tube.

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35
Q

What is the oblique sinus?

A

It is found near the LA. It is a cul-de-sac–can’t get your fingers all the way thru.

Laterally: see IVC & pulmonary veins.

Posteriorly: see pericardial separation & on the other side the esophagus.

36
Q

what tissue type lines the oblique sinus?

A

Serous pericardium on either side. Visceral reflected on parietal.

37
Q

what makes up the base of the heart?

A

Mainly the LA & some RA. This is the posterior portion of the heart & is just anterior to the esophagus.

38
Q

What is the purpose of transesophageal echoes?

A

The esophagus runs just behind the base of the heart (posterior portion). So the echoes can tell information about valves for valve replacement b/c it’s right there!

39
Q

What is the apex of the heart?

A

The tip of the left ventricle. Pushed somewhat off towards the left.

40
Q

What makes up the diaphragmatic portion of the heart?

A

The RV & LV.

41
Q

Where do the left coronary artery & right coronary artery come from?

A

Come out of the aorta! Out of openings called ostea. They are associated w/ cusps of the aorta. Come off of right & left cusps. Nothing comes off the posterior cusp.

42
Q

What does the left coronary artery branch into?

A

LAD & Circumflex.

Circumflex branches into 1-3 obtuse Marginal arteries (OM1)

43
Q

What follows the LAD & circumflex?

A

The Great cardiac vein

44
Q

Where does the circumflex run?

A

In the atrioventricular sulcus

45
Q

What are the branches of the right coronary artery?

A

Right Away: Right atrial branch

–off the right atrial branch you get the SA nodal branch (supplies the SA node behind the superior vena cava)

Usu one acute marginal artery

46
Q

What else can sometimes supply the SA node?

A

A branch off of the circumflex.

47
Q

What does crista terminalis separate?

A

The smooth & rough walls of the right atrium.

Corresponds to a sulcus terminalis that can be seen near the inferior vena cava on the posterior side of the heart. This sulcus extends upward to the SA node.

48
Q

Whas is the difference b/w a right dominant heart & a left dominant heart?

A

Right DOminant: the PD branches off of the right coronary artery.

Left Dominant: the PD branches off of the circumflex.

49
Q

What are the least cardiac veins?

A

Super teeny tiny veins that drains directly into the walls of the heart.

50
Q

Explain the venous drainage of the heart.

A

Great Cardiac Vein (runs along LAD & circumflex)

Middle Cardiac Veins (runs along PD)

Small Cardiac Vein (runs w/ right coronary artery in the interventricular sulcus)

All 3 veins drain into the coronary sinus.

The Coronary sinus drains in the ostea of the coronary sinus directly into the RA.

51
Q

What are you looking for with arteriography?

What is the danger?

A

See if there is a blockage in a coronary artery.

Can accidentally cause a dissection of the coronary artery near the ostea.

52
Q

What is the difference b/w end arteries & anastomoses? How does this relate to coronary arteries?

A

End Arteries: no other arteries supply that area of the heart. Most coronary arteries are end arteries.

If you get a blockage in an end artery, the tissue will infarct & become scar tissue.

Anastomosis: is an area where multiple coronary arteries supply one area.

This applies to the apex of the heart (LAD & PD) & the septum of the heart. All the teeny tiny coronary arteries come off the PD & into the interventricular septum.

53
Q

What is the widowmaker?

A

When a person has a left dominant heart (The PD comes off of the circumflex) & they have a blockage in their left coronary artery.

If they were right dominant, we wouldn’t be as worried.

54
Q

What happens if your tricuspid valve is incompetent?

A

You get blood flowing back from RV to RA. You will hear a murmur. There is reduced cardiac output on this side of the heart. There is a build up of blood. Heart failure on the right side. Dilation of the RA.

55
Q

What is the rough wall called in the atria? In the ventricles?

A

Atria–pectinate muscles

Ventricles–trabeculae carnae

56
Q

Where is the SA node located?

A

In the R. Atrium. near the superior vena cava.

57
Q

Where is the AV node located?

A

Located in the interatrial septum near the opening of the coronary sinus.

58
Q

What is a structure that helps transmit impulses from the SA node to the AV node?

A

Crista terminalis has myocardial bundles that do this.

59
Q

What does the crista terminalis separate?

A

The rough from the smooth wall of the R. Atrium.

60
Q

Where is the crista terminalis located?

A

In the R. Atrium. On the inside of the sulcus terminalis.

61
Q

What is/where is the sulcus terminalis?

A

It is a groove on the outside of the heart b/w the inferior vena cava & the right auricle.

62
Q

What is the fossa ovalis?

A

It is the adult nonactive version of the foramen ovale in the little itty bitty kid. It is located in the R. Atrium near the opening to the inferior vena cava.

63
Q

What is the foramen ovale? What does it become in adults if all goes well? WHat does it become in adults if all does NOT go well?

A

It is a right to left shunt that brings blood from the R. Atrium to the L. Atrium bypassing the lungs, good for fetal development. In adults, it isn’t active & it’s called the fossa ovalis. If it is open in adults it is called a patent foramen ovale.

64
Q

What is an auricle? Where is it found? Is it dangerous?

A

It is found on the right & left atria. Sorta a remnant from the original atria. It can be dangerous b/c blood can pool there & then form clots that travel as emboli to dangerous places.

The Left Auricle is more dangerous b/c it can throw a clot out of the aorta, which will often go straight to the brain.

The Right Auricle is less dangerous b/c it can still throw a clot to the lungs.

65
Q

T/F The valves of the heart are in 2 separates planes.

A

False. They are all in one plane.

66
Q

Do the pulmonic & aortic valves have chordae tendinea & papillary muscles?

A

NO. Because they have the semilunar valves & don’t need the contraction of the chordae & pap to prevent prolapse.

67
Q

What is the purpose of the fibrous skeleton of the heart?

A

It is the main attachment site in the heart for things like valves. It is also an insulator, insuring that the conductance from the SA node goes to the apex before the ventricles.

68
Q

What can cause acute valvular insufficiency?

A

When the chordae tendineae break off of the cusps of the AV valves.

69
Q

What can cause chronic valvular insufficiency?

A

When there is a slight prolapse that gets worse over time.

70
Q

What happens w/ valvular insufficiency?

A

A buildup of blood in the chambers.

71
Q

What prevents valve prolapse? W/ AV valves?

A

The chordae tendineae are attached directly to the cusps of the AV valves. They are then attached to papillary muscles of the heart wall. R: anterior, posterior, septal; L: anterior, posterior. Together, they keep the AV valves closed. With the contraction of the heart, the papillary muscles also contract to keep the chordae tendineae tense.

72
Q

What is the moderator band?

A

aka septomarginal trabecula. Connects to the anterior papillary muscle & to the septum of the heart.

73
Q

What is the conus arteriosis?

A

It is the area of smooth wall found right before the pulmonic valve in the RV.

74
Q

What are the 3 layers of the heart muscle (inner–>outer)?

A

Endocardium

Myocardium

epicardium

75
Q

What is on each of the borders of the heart?

A

R. Border: R. Atrium

L. Border: L. Ventricle

Anterior Border: R. Ventricle

Posterior Border: L. Atrium (sorta the base of the heart)

76
Q

What is on the diaphragmatic surface of the heart?

A

The Right ventricle mainly, with a little bit of left ventricle.

77
Q

T/F The Left Atrium is entirely full of pectinate muscles, very rough wall.

A

False. The left atrium is mainly smooth. Exception is in the left auricle that has pectinate muscles.

78
Q

What is the aortic vestibule?

A

It is the smooth part leading to the aortic valve.

79
Q

What is the common plane that all heart valves lie in?

A

The plane of the atrioventricular sulcus.

80
Q

When do the coronary arteries fill up?

A

Diastole!!

81
Q

How can semilunar valves become incompetent?

A

If they are too small (stenosis) or have calcifications.

The body sometimes compensates w/ l. ventricular hypertrophy if there is aortic stenosis.

82
Q

What protects the wall of the aorta?

A

A sinus that always has at least a little bit of blood.

83
Q

Which of these nerves runs behind the root of the lung & which runs in front?

Vagus or Phrenic?

A

Vagus–behind the root of the lung

Phrenic–in front of the root of the lung

84
Q

What does sympathetic stimulation do to the diameter of the coronary arteries?

A

Symp activation dilates the coronary arteries.

85
Q

Where are the heart sounds?

A

2 intercostal space: R (Aortic) L (Pulmonic)

Tricuspid sorta above the xiphoid

Mitral in the 5th intercostal space on the left. Apex of the heart

86
Q
A