Unit 2 Heart And Mediastinum

Front 1

What are the boundaries of the mediastinum

Back 1

left and right= pleural cavity, diaphragm, fiberous pericardium
superior- left and right pulm arteries

Front 2

Access to the pericardial cavity is usually gained by a longitudinal incision in order to avoid injury to...

Back 2

phrenic nerves that run along the lateral borders of the pericardial sac

Front 3

What two layers comprise the pericardial sac

Back 3

-fibrous pericardium
-serous pericardium (which consists of parietal and visceral)

Front 4

The fibrous pericardium is attached to the the mediastinum via...

Back 4

1. central tendon of diaphragm
2. sternal periosteum

Front 5

The function of the fibrous pericardium is to

Back 5

prevent overdistention of the heart

Front 6

The subdivisions of the serous pericardium are

Back 6

1. parietal serous pericardium that lines the pericardial cavity
2. visceral serous pericardium (epicardium) that lines the great vessels and surface of the heart, forms the outermost layer of the heart wall

Front 7

What is the function of pericardial fluid

Back 7

keeps surface layers moist and slippery, allows nearly frictionless beating of heart within pericardial cavity

Front 8

What are thw two pericardial sinuses? how are they formed

Back 8

1. Oblique (scoop)
2. Transverse (behind aorta and pulm trunk)
Formed when parietal pericardium reflects around great vessels and surface of heart to become visceral pericardium

Front 9

What is pericardial tamponade? Where does it occur?

Back 9

-Accumulation of fluid in the pericardial sac
-compresses heart reducing CO and increasing HR, rapid weak pulse
-associated with jugular vein distension, edema, dyspnea

Front 10

What route would be the safest to preform a pericardiocentesis? What structures are you avoiding using this route.

Back 10

-Left side of chest adjacent to xyphoid process angling upwards and to the left in the costal mediastinal recess
-Decreases the risk of pneumothorax because the plueral cavities are avoided
-also avoids LAD or Rt. marginal arteries

Front 11

Pericarditis can result in refered pain to the precordium and epigastrium. What heart structure is inflammed?

Back 11

Parietal serous pericardium

Front 12

Describe the size of a normal heart on a radiograph

Back 12

the transverse diameter should not be more than half the diameter of the chest

Front 13

The coronary (atriobentricular) sulcus encircles the heart and divides the atria from the ventricles. What 4 structures are found in this region?

Back 13

1. circumflex branch of L. coronary a.
2. right coronary a.
3. coronary sinus
4. small cardiac vein

Front 14

The anterior interventricular sulcus marks the location of the interventricular septum, seprating the ventricles. What two structures can be found here?

Back 14

1. LAD (anterior interventricular artery)
2. great cardiac vein

Front 15

The posterior interventricular sulcus delineates the IV septum posteriorly. What two structures can be found here?

Back 15

1. posterior IV (descending) artery
2. middle cardiac vein

Front 16

Describe the course and list the three major branches of the right coronary artery. What areas of the heart do the branches supply?

Back 16

Course: Arises from the aorta and runs through the coronary sulcus.
Branches
1.nodal branch supplying R atrium and SA node
2. Rt. marginal branch supplying RV
3. Posterior IV (descending) branch suppling posterior 1/3 of IV septum

Front 17

Describe the course and list the two major branches of the left coronary artery. What areas of the heart do the branches supply?

Back 17

Course: Arises from the aorta and runs between the pulmonary trunk and aorta before bifurcating.
Branches
1. anterior IV/ LAD-enters the anterior IV sulcus, supplies anterior aspect of L. and R. ventricules
2. Circumflex-coronary sulcus toward left boder and around ot base of heart

Front 18

Variations in coronary circulatory system can result in a right dominant or left dominant heart. Explain what this means

Back 18

The difference depends on which coronary artery is the origination of the posterior IV branch
right dominant= right artery
left dominant= left artery

Front 19

T/F anastomoses are common in the coronary circulation

Back 19

False, most are true end arteries with little overlap. Any anastomoses are generally inadequate to maintain effective circulation in the event of sudden occulsion

Front 20

Obstruction in a coronary artery produces ischemia. Pain associated with ischemic tissue is usually refered to...

Back 20

precordium, epigastrium, shoulder, left arm

Front 21

When does blood flow through the coronary circulation of the left ventricle?

Back 21

Only during diastole, this is due the left ventricular pressure and left ventricular transmural pressure being greater than or equal to aortic systolic pressure

Front 22

The majority of the venous return from the epicardium and myocardium drain via...

Back 22

coronary sinus

Front 23

What are the three main tributaries to the coronary sinus? What structures do they acompany?

Back 23

1. great cardiac vein w/ LAD
2. middle cardiac vein w/ Posterior IV artery
3. small cardiac vein w/ R. conronary a. and marginal branch

Front 24

What three structures drain into the R. atrium

Back 24

1. SVC
2. IVC
3. coronary sinus

Front 25

Where are pectinate muscles found?

Back 25

right atrium, running across atrial wall and attaching to chordae tendinae which attach to the tricuspid valve
(Christ entered and Peck'ed the Righteous)
(crista terminale and pectinate are in the right atrium which is the entry)

Front 26

Where is the fossal ovalis located

Back 26

Interatrial septum

Front 27

Which ventricle has thicker walls

Back 27

left because it has to supply the entire body

Front 28

Which valve conducts blood between the right atrium and right ventricle

Back 28

tricuspid (tri before you buy)

Front 29

What portion of the interventricular septum is most often the site of ventricular septal defects?

Back 29

membranous portion

Front 30

which type of shunt will result in cyanosis/ "blue baby"

Back 30

right to left
"left to right won't make you bright"

Front 31

What is the purpose of the pulomonary semilumnar valve? How many cusps does it have and what are they called?

Back 31

-prevents regurgitation of ejected blood from the pulmonary trunk back into the right ventricle
-three cusps: left, right, anterior

Front 32

What valve conducts blood from the left atrium to the left ventricle

Back 32

mitral/ bicuspid
(tri before you bi)

Front 33

Describe the heart problems associated with mitral valve insufficiency

Back 33

A defective mitral valve will cause blood to flow back in to the LV during diastole. This will increase LV pressure leading to left side heart failure. If the LV pressure is transmitted back to the lungs, pulmonary edema, pleural effusion, and right side heart failure can result

Front 34

What is the purpose of the aortic semilunar valve? How many cusps does it have and what are they called?

Back 34

-prevents backflow of blood back into the LV during diastole
-three cusps right, left, posteior

Front 35

Where are the aortic sinuses? Where are they located? What is their purpose?

Back 35

Slight depressions in the walls of the aorta behind the vavle cusps. They accomodate the volume of the open leaflets to reduce turbulent flow during ejection. They also provide the origins of the coronary arteries

Front 36

Where do the coronary arteries originate

Back 36

the right and left aortic sinuses

Front 37

What neve supplies parasympathetic control to the heart? What are the affects of parasympathetic signaling

Back 37

Vagus nerve preganglionic fibers synapse with small postganglionic fibers in the myocardium. Parasympathetic signaling slows heart rate and reduces stroke volume

Front 38

What nerve supplies sympathetic innervation to the heart? What are the affects of sympathetic signaling

Back 38

Postganglionic sympathetic nerves run from the upper sympathetic chain ganglia to the heart. They terminate near the SA and AV nodes and the ventricular musculature. Sympathetic activity accelerates the heart rate and increases stroke volume

Front 39

Visceral afferent fibers that run from the heart enter the spinal cord at what levels?

Back 39

T1-T5
this (partially) explains the dermatome distriubtion of chest pain assocaited with a heart attack

Front 40

Where would you ascultate each of the four valve sounds?

Back 40

"AParTment M", zorro sign across chest
1. aortic= right of sternum 2nd intercostal space
2. pulmonary= left of sternum 2nd intercostal space
3. tricuspid= left of sternum, 4th intercostal space
4. Mitral= right of sternum 5 intercostal space below left nipple

Front 41

Describe the heart problems associated with tricuspid valve insufficiency

Back 41

-Casues blood to flow back into RA during RV systole
-increase in RV pressure which is transmiited back to venous system producing distended neck veins, abdominal ascietes, and edema

Front 42

What is the spatial relationship of arteries and veins in the superior mediastinum

Back 42

Veins are anterior and to the right, ateries are posterior and to the left

Front 43

What 3 veins unite to form the SVC

Back 43

R. and L. brachiocepalic, (note that azygous enters into SVC near this juntion)

Front 44

What is the "aortic knob"

Back 44

a radiographic landmark produced by the aortic arch passing on the left side of the mediastinum

Front 45

What are the 5 branches off the ascending aorta

Back 45

1. left coronary
2. right coronary
3. brachiocephalic (right side only, gives rise to R. common carotid and R. subclavian)
4. L. common carotid
5. L. subclavian

Front 46

Where is the posterior mediastinum

Back 46

-behind the pericardial sac
-bounded by mediastinal pleura on either side and diaphragm below

Front 47

Describe the course of the thoracic duct

Back 47

-In the abodomen, the duct originates i fthe cisterna chyli located at T12 between the crura of the diaphragm and posterior to the aorta
-Courses up through the thorax behind the esophagus and to the right of the aorta
-In superior mediastinum the duct arches the cupula of the left pleura to posteriorly to the L. subclavian vein. Enters the vein at the angle formed by the junction of L. subclavian and L. internal jugular

Front 48

Describe the venous drainage of the thorax

Back 48

-azygous vein on R. of esophagus receives blood from R. post. intercostals, R. bronchial, and hemiazygous
-Acessory receives from upper left and joins azygous
-hemi drains from lower left and joins azygous

Front 49

There are 12 sympathetic ganglia in the thorax each of which has 5 connections. What are the 5 connections each ganglia has

Back 49

1. white rami communicantes
2. grey rami communicantes
3. superior connector
4. inferior connector
5. splanchnic nerve

Front 50

What type of neurons do white rami communicantes carry? What is their course?

Back 50

Bring presynaptic myelinated GVE fibers from the spinal nerve to the sympathetic chain