HS2-16 Heart Flashcards
What are the four chambers of the heart?
right atrium
left atrium
right ventricle
left ventricle
What are the vessels travelling to the heart? (2)
superior/inferior venae cavae
pulmonary veins
What are the vessels travelling from the heart? (2)
aorta
pulmonary trunk (main pulmonary artery)
How does the main pulmonary artery branch?
branches into left and right pulmonary arteries
What are the four valves of the heart? Where are they located?
tricuspid valve = between right atrium and right ventricle
bicuspid valve = between left atrium and left ventricle
pulmonary valve = between right ventricle and pulmonary trunk
aortic valve = between left ventricle and aorta
Describe the pathway of circulation to the heart (the deoxygenated/venous system). (6)
inferior/superior venae cavae + coronary sinus → right atrium → right ventricle → pulmonary trunk → pulmonary arteries → lungs
Describe the pathway of oxygenated blood (the arterial system). (6)
lungs → pulmonary veins → left atrium → left ventricle → aorta → body
Draw a trapezoidal schematic of the heart, and identify each of the borders.
What is the apex of the heart?
junction of left and right ventricles
What is another name for the atrioventricular groove?
coronay sulcus
What is the function of the auricles of the heart?
increase capacity of atria
What heart structures are visible on a PA CXR? (5)
right atrium
aortic arch
main pulmonary artery
left auricle
left ventricle
What heart structures are visible on a lateral CXR?
right ventricle
left atrium
How can heart size be estimated on CXR? (@)
cardiothoracic ratio = transverse heart size/transverse thoracic diameter
normal cardiothoracic ratio is less than or equal to 0.5
Which type of CXR is not appropriate for calculating the cardiothoracic ratio?
AP view, since the heart is magnified in the AP view
What are the three layers of the pericardium?
fibrous
parietal serous
visceral serous
The fibrous layer of the pericardium is continuous with
the central tendon of the diaphragm
Order the three layers of the pericardium.
fibrous
parietal serous
visceral serous (adhered to heart)
Where is the pericardial cavity?
between the two serous layers (parietal serous and visceral serous)
The pericardial cavity contains
pericardial fluid
What are the two passages of the pericardial cavity?
transverse pericardial sinus
oblique pericardial sinus
Where is the transverse pericardial sinus located? (2)
anteriorly = between aorta and pulmonary trunk
posteriorly = between superior vena cava and pulmonary vein
Where is the oblique pericardial sinus located?
posterior to left atrium, bound by pulmonary veins
What is the blood supply to the pericardium?
pericardiacophrenic arteries
What is the innervation to the pericardium?
phrenic nerve
What is pericardial effusion?
fluid accumulating in the pericardial space
What are the appropriate radiographic imaging methods to visualize pericardial effusion? (3)
echocardiography
CT
MRI
[not CXR, because of heart enlargement]
What is the function of the fibrous skeleton of the heart?
functions as insulator between atria and ventricles
The fibrous skeleton of the heart provides attachment for (2)
myocardial fibers
structures of the valves
The fibrous skeleton of the heart forms what structures? (2)
forms 2 trigones to connect the rings around the orifices of the valves
forms membranous portion of interatrial and interventricular septa
What are the two regions of the right atrium?
rough region = true atrium
smooth region = sinus venarum
What are the contents of the rough region of the right atrium? (3)
pectinate muscles
crista terminalis
opening to right auricle
What are the contents of the smooth region of the right atrium? (3)
openings for superior/inferior venae cavae
opening for coronary sinus
fossa ovalis
What is the fossa ovalis?
remnant of fetal foramen ovale in the heart
Which valves are found in the right ventricle?
tricuspid valve, which controls opening b/w right atrium and right ventricle
pulmonary valve, which controls opening b/w right ventricle and pulmonary trunk
What is the function of the chordae tendinae?
connect papillary muscles to valve cusps
What is the septomarginal trabecula?
structure involved in impulse conduction that runs from interventricular wall to base of anterior papillary muscle
What is another name for the infundibulum?
conus arteriosus
What are the contents of the left atrium? (3)
openings for 4 pulmonary veins (mostly smooth)
opening to left auricle (rough)
fossa ovalis
What muscle is found in the left auricle of the heart?
pectinate muscles
What valves are found in the left ventricle?
bicuspid valve (a.k.a. mitral valve), which controls opening b/w left atrium and ventricle
aortic valve, which controls opening b/w left ventricle and aorta
What are the semilunar valves? (2)
pulmonary valve
aortic valve
What are the contents of the right ventricle?
papillary muscles (anterior/posterior/septal)
moderator band a.k.a. septomarginal trabecula
conus arteriosus a.k.a. infundibulum
trabeculae carnae
What is the function of the heart’s moderator band (the septomarginal trabecula)?
carries impulse to the anterior papillary muscle
What is the ventricular analog of the pectinate muscles found in the heart atria?
trabeculae carnae
What is the relationship between the moderator band and the papillary muscles?
moderator band allows simultaneous contraction of papillary muscles
(T/F) The papillary muscles shut the heart valves.
False. They don’t shut the valves, but they do keep them shut.
What are the contents of the left ventricle? (2)
papillary muscles (anterior, posterior) to keep mitral valve shut
trabeculae carnae
Draw a diagram of the auscultation points. What is the associated mnemonic?
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Aortic = 2nd intercostal space, right of sternum
Pulmonary = 2nd intercostal space, left of sternum
Tricuspid = 5th intercostal space, left of sternum
Mitral = 5th intercostal space, left mid-clavicular line
Describe the attachment of the bicuspid and tricuspid valve cusps. (2)
bases of valve cusps attached to fibrous skeleton
free ends of valve cusps attached to papillary muscles, via chordae tendinae
Describe the role of the papillary muscles in relation to the bicuspid and tricuspid valves.
papillary muscles contract at beginning of systole, drawing cusps together and preventing them from prolapsing into atrium
Describe the shape of the semilunar valves.
concave
Describe the shape and function of the semilunar valves during systole and diastole.
systole = cusps pressed against arterial wall
diastole = blood flows back in direction of ventricle but collect in concave cusps, so edges of cusps are pressed against each other
What are the coronary arteries?
branches of ascending aorta that supply the myocardium
Where does the right coronary artery run?
runs in coronary sulcus = atrioventricular groove
What are the branches of the right coronary artery? (4)
posterior interventricular branch = posterior descending artery [clinical term]
marginal branch
branch to SA node
branch to AV node
Where does the posterior descending artery run?
runs in posterior interventricular groove
What are the branches of the left coronary artery? (2)
circumflex branch
anterior interventricular branch = left anterior descending artery (LAD) [clinical term]
Where does the circumflex branch of the left coronary artery run?
atrioventricular groove
Where does the anterior interventricular branch of the left coronary artery run?
anterior interventricular groove
How can you distinguish between the left and right coronary arteries?
left coronary artery bifurcates into 2 branches near origin
List the structures supplied by the right coronary artery. (5)
right atrium (via atriach branch)
most of right ventricle (via right marginal artery)
part of left ventricle
posterior part of interventricular septum (via posterior descending artery)
SA/AV nodes
List the structures supplied by the left coronary artery. (4)
left atrium
most of left ventricle (circumflex branch)
part of right ventricle
anterior portion of IV septum (left anterior descending artery)
The cardiac veins arise from
the myocardium
The posterior interventricular artery anastomoses with
the left anterior descending artery
At what point does the right coronary artery become the posterior interventricular artery?
in the posterior interventricular groove
In what structure does the left circumflex artery run?
AV groove
The left circumflex artery anastomoses with
the right coronary artery
Where do the cardiac veins drain?
drain into coronary sinus, then right atrium
The great cardiac vein runs with what vessel in what structure?
runs with left anterior descending artery in anterior interventricular groove
The middle cardiac vein runs with what vessel in what structure?
posterior descending artery in posterior interventricular groove
The small cardiac vein runs with what vessel in what structure?
runs with marginal branches from right anterior margin to atrioventricular groove
The coronary sinus opens into
the right atrium
The coronary sinus runs in what structure?
atrioventricular groove
What are the four primary venous structures associated with the heart?
great cardiac vein
middle cardiac vein
small cardiac vein
coronary sinus
What is the exception to the rule that all venous structures of the heart drain into the coronary sinus?
the anterior cardiac vein, which drains the right ventricle, crosses the right coronary artery to drain directly into the right atrium
What is the mnemonic to remember how the cardiac veins run?
a great LAD was caught in the middle of PDA but escaped by a small margin
Where is the SA node located?
wall of right atrium at superior end of crista terminalis
What is the function of the SA node?
pacemaker that initiates impulse that spreads through atria and causes them to contract
Where is the AV node located?
postero-inferior region of interatrial septum, superior to the opening of the coronary sinus
What is the function of the AV node?
receives impulses from cardiac fibers of atria and distributes impulses to AV bundle
What is another name for the AV bundle?
bundle of His
Draw a diagram of the intrinsic innervation pathway of the heart.
Sympathetic innervation of the heart comes from
the sympathetic trunks
What is the function of sympathetic innervation to the heart? (3)
increases heart rate
increases force of contraction
dilates coronary arteries
What is the function of parasympathetic innervation to the heart? (3)
decreases heart rate
decreases force of contraction
constricts coronary arteries
Parasympathetic innervation of the heart comes from
the vagus nerve
Describe how the visceral sensory fibers of the myocardium are related to the phenomenon of referred pain. (4)
visceral sensory fibers of myocardium activated by ischemia
fibers run with sympathetic fibers of cardiac plexus to spinal cord
fibers enter spinal cord at T1-T4/T5 and synapse at C3-T5
referred pain felt in dermatomes of C3-T5, most often on left side
What is diastole?
relaxation and filling of ventricles with blood
What is systole?
ventricular contraction and emptying of ventricular blood into aorta + pulmonary trunk
List the events during diastole. (3)
pulmonary and aortic valves close
walls of ventricles relax
tricuspid and bicuspid valves open so blood flows into ventricles
List the events during systole. (3)
walls of ventricles contract
tricuspid and bicuspid valves close
pulmonary and aortic valves open
The contraction of the atria and ventricles is regulated by
the intrinsic impulse conduction system of the heart
