Heart Flashcards
Where is the heart found?
Mediastinum in the pericardium
Where is the mediastinum?
Between the pleural cavities
What features of the left lung allow the heart to fit?
Cardiac notch
Lingula
Where is the apex of the heart?
5th intercostal space, left of sternum
What is the path of blood flow into the right ventricle (systemically)?
Internal jugular and subclavian join to form brachiocephalic (L & R)
Brachiocephalic veins join to form superior vena cava
Inferior vena cava drains abdomen and lower limbs
Coronary sinus
All of these go into the right atrium and then blood moves through the tricuspid valve into right ventricle
How many vessels enter the left atrium and what are they called?
Two pairs
Pulmonary veins
What valve is between the left atrium and ventricle?
Mitral valve
What are the three branches of the aortic arch?
Brachiocephalic trunk
Left common carotid
Left subclavian
What do valves do?
Prevent backflow of blood
What are the shapes of the atrioventricular valves described as?
Parachute-shaped
When are the atrioventricular valves shut?
Ventricular systole
When are the semilunar valves open?
Ventricular systole
How many cusps do each of the atrioventricular valves have?
Tricuspid - 3
Mitral - 2
What do papillary muscles do?
Hold chordae tendineae taut so atrioventricular valves do not prolapse
Where are papillary muscles found?
Ventricles
How many cusps do the semilunar valves have?
3
Where would you put a stethoscope to hear the sound of the mitral valve?
5th intercostal space, left of sternum (apex)
Where would you put a stethoscope to hear the sound of the tricuspid valve?
5th intercostal space, just left of sternum
Where would you put a stethoscope to hear the sound of the pulmonary valve?
2nd intercostal space, left of sternum
Where would you put a stethoscope to hear the sound of the aortic valve?
2nd intercostal space, right of sternum
When emerging from the heart/ventricles, which artery is anterior?
Pulmonary
Where is the right auricle?
Covers right atrium and hugs aorta
Where are pectinate muscles found?
Atria (less so in the left atrium)
What do pectinate muscles do?
Aid atrial systole
What is the fossa ovalis and where is it found?
Remnant of the developmental foramen ovale
Thumb-like depression in inter-atrial septum
What is trabeculae carnae and where is it found?
Meaty muscles partially lining ventricle walls
What is the ligamentum arteriosum and where is it found?
Remnant of ductus arteriosis
Between pulmonary artery and aortic arch
What vessels supply oxygenated blood to the heart?
Coronary arteries
Where do coronary arteries arise?
Aortic sinuses, just superior to aortic valve
What does the right coronary artery “pass through”?
Right atrioventricular groove
What are the three branches of the right coronary artery?
Nodal branch
Right marginal branch
Posterior interventricular branch
What does the nodal branch supply?
Conducting system of heart (SAN and AVN)
What would happen if the nodal branch was blocked?
Heart would not beat
What makes a heart “right dominant”?
Blood supply for nodes comes from right coronary artery
What are the branches of the left coronary artery?
Anterior interventricular branch
Circumflex branch
Left marginal branch
What is another name for the anterior interventricular branch?
Left anterior descending
What does the anterior interventricular branch supply?
Left ventricle
Where does the circumflex branch go?
Curves under left auricle to posterior of heart
Describe the venous drainage system of the heart
Great, middle and small cardiac veins drain into coronary sinus into the right atrium
Where does the coronary sinus run?
Posteriorly between atria and ventricles
Where does the great cardiac vein run?
With left anterior interventricular branch
Where does the middle cardiac vein run?
In posterior interventricular groove
Where does the small cardiac vein run?
With right marginal artery
What is the cardiac skeleton and its functions?
Fibrous connective tissue
- allows sequential contraction (insulates)
- fibrous rings anchor valve cusps
- points of insertion of bundles of heart muscle
Where is the sinoatrial node found?
Right atrium
Where is the atrioventricular node found?
Atrial side of cardiac skeleton
What does the sinoatrial node do?
Releases spontaneous electrical stimuli at a regular rate
Describe the conduction of electrical stimuli through the heart
Generated spontaneously by SAN
Travels down walls of atria and converges on AVN
After a short delay, signal passes down bundle of His in interventricular septum
Then along Purkinje fibres
Ventricles contract bottom-up
What are the layers of the pericardial sac?
Visceral pericardium/epicardium (serous)
Parietal pericardium (serous)
Fibrous pericardium
What is a difference between the pericardium and pleura?
No negative pressure in pericardium
What is the space between the serous pericardium layers called?
Pericardial cavity
What is the fibrous pericardium?
Restrictive capsule of heart
What is the pericardial sac attached to?
Central tendon of diaphragm
Sternum
What are the functions of the pericardial sac?
Anchor
Prevent overfilling
Protection
Lubrication
