Dr. Seiden - Lecture 1 - Anatomy of the Heart Flashcards
Interventricular sulcus
Seperates left and right ventricle. Great cardiac vein and anterior interventricular artery (LAD) run here.
Tricuspid valve
Mitral valve
Tricuspid - atrioventricular valve on the right side
Mitral - atrioventricular valve on the left side
Pulmonic valve
Aortic valve
Pulmonic - outflow valve on the right side
Aortic - outflow valve on the left side
When are the AV valves open/closed and when are the outflow valves open/closed?
AV valves are open during diastole and closed during systole.
Outflow valves are closed during diastole and open during systole.
What is diastole and what is systole?
Diastole is when the ventricle is contracting and systole is when the ventricle is relaxing.
Portions of the aortic and pulmonic valves
A - Right, Left, Posterior
P - Right, Left, Anterior
Semilunar nodules
the corner portion of the semilunar valves are called the semilunar nodule. When the valve closes, they fit into each other to close the valve
Portions of the mitral and tricuspid valves
Mitral - Anterior and Posterior
Tricuspid - Anterior, Posterior, Septal
Normal auscultation points
Aortic Valve - right second intercostal space because the aortic valce is between left ventricle and ascending aorta. We want scope over ascending aorta. Aorta is on the right so you want to be over the right side.
Tricuspid valve - Valve between right atrium and right ventricle. So you want to place your stethoscope over the right ventricle (downstream). Don’t put it over the sternum, but rather over the intercostal space. We pick the 5th (as opposed to 3rd and 4th) intercostal space because the heart is tilted forward so we can hear the lower parts better.
Mitral valve - 5th intercostal space at the midclavicular line. You want to be in the left ventricle, downstream). We pick 5th as opposed to 4th and 3rd because the heart is tilted forward.
Pulmonic valve - second intercostal space on the left between pulmonic trunk and right ventricle. You want to go downstream
stenosis
incompetence
stenosis - narrowing of an opening in a valve.
incompetence - a valve doesn’t close as it should so we have regurgitation.
AV Valve Murmers
Stenosis - Diastolic murmer - Lub-Dub-Pshh
Insufficiency - Systolic murmer - Lub-Psh-Dub
Outflow Valve Murmers
Stenosis - Systolic murmur - Lub-Psh-Dub
Insufficiency - Diastolic murmur - Lub-Dub-Psh
Auscultation Points for murmurs
Slide 18
Pectinate Muscle
Rough wall
Crista Termanlis
ridge separating rough and smooth wall
Fossa Ovalis
- Limbus of fossa ovalis
Oval depression on right atrial side of right atrium.
- Limbbus - sharp upper border of fossa ovalis
Trabeluae Carnae
Same thing as pectinate muscle that we saw earlier.
Chorda tendinae
attach to the papillary muscles. Tips of papillary muscles to edges of the cusps. Do not pull on the valves. The opening and closing of the tricuspid valve is purely based on pressure between the two ventricles. But if the pressure in the second valve gets too high then it would go from open to closed to open. But because we have the chordae tendinae, it tethers it so that it can’t go passed closed
Blood Supply to the heart?
Right and left coronary arteries coming off of the ascending aorta
Right coronary artery
leaves ascending aorta and ngoes straight to the coronary sulcus (atrioventricular sulcus). It supplies the right atrium and right ventricle. It gives off a branch callrd the SA Nodal Artery. It then continues to give off a branch called the marginl artery. leaves ascending aorta and ngoes straight to the coronary sulcus (atrioventricular sulcus). It supplies the right atrium and right ventricle. It gives off a branch callrd the SA Nodal Artery. It then continues to give off a branch called the marginl artery.
Right Dominance vs. Left dominance
Right Dominance is when the posterior inerventricular artery comes off of the right coronary artery. Left Dominance is when the Posterior interventricular Artery comes off of the Left coronary artery.
Left Coronary Artery
coems off of left side of ascending aorta. very short. Once it gets past the pulmonary trunk it ends and divides into two branches. The first branch is the left circumflex artery, which goes around to the posteior part of the heart, makes a U-turn and enters the coronary sulcus. The second branch is the anterior interventricular antery, which supplies the two ventricles.
Two sites of anastemoses in the heart
1) Between right and left coronary artery by way of the circumflex artery.
2) Anterior and posterior interventricular arteries.
Great cardiac vein
Venous drainage - Great cardiac - sits in anterior interventricular sulcus on the anterior portion of the heart and runs parallel with the LAD. It then ascneds into the coronary sulcus, goes to the back of the heart in the coronary sulcus, it then expands to become what is called the coronary sinus
Coronary Sinus
the great cardiac vein as well as the other cardiac veins such as the small cardiac and middle cardiac all flow into the coronary sinus. The coronary sinus then flows into right atrium.
Anterior cardiac veins
Drain directly into the right atrium
Least Cardiac Veins (Thebesian Veins)
drains directly into whatever chamber is underlying that vein. Therefore, usually you get your venous return going into the right atrium. But now we see that you also get some venous return going into the left atrium and left ventricle. Therefore, you get some deoxygenated blood getting into the left side of the heart, which makes it so that the blood in the pulmonary venous return isn’t 100% oxygenated. The blood that is flowing into the right atrium is 100% saturated, and blood going into the left atrium is 100% saturated. The blood that is leaving the left ventricle is not 100% saturated, its like 95%.
Pericardial Cavity
- Visceral pericardium
- parietal pericardium
heart is surrounded by the pericardial cavity, which is made up of the visceral layer and parietal layer. The visceral layer is on the inside, the parietal layer is on the outside.
Fibrous peericardium
as opposed to the abdomen, we have a third layer here called the fibrous pericardium, which is fused to the parietal pericadium. Very tough collagenous layer. If you cut into it you would see the parietal pericardium. It doesn’t stretch. If you get a rapid accumulation of fluid into the pericardial cavity, the cavity cant expand to accommodate this volume of fluid. So, it’ll expand inward and compress the heart. This will impede filling of the heart. Called pericardial tamponade, which is fixed through a procedure called pericardiocentesis
Transverse Sinus
If you slide your finger behind the pulmonary trunk, the finger would go behind the pulmonary trunk, behind the ascending aorta, submerge between ascending aorta and SVC. You would have the outflow vessels in front of the finger and the inflow vessels behind the finger.
Oblique Sinus
if you pull the heart forward and slide your finger behidn the heart, you would be sliding up onto the left atrium, and as you contnue on the hand would pass between the left and right pulmonary veins, and you would end up in a blind ending sinus.
Sinuatrial Node
- Fibrous skeleton
In cardiac cells, there is electrical communication between the cells. Whicheevr cells depolarizes fastest will dictate the rate of contractin of the heart. This is the Sinuatrial Node (SA Node) and act as a pacemaker. of the heart The only caveat is that the atrial muscle cells do not communicate with the ventricular cells. This is because there is a fibrous connective tissue called fibrous skeleton, which seperates the two. Therefore their rates are different. When it deolarizes, it hits all of the atrial cells, gets to the AV node. Once it gets to the AV node it slows down and eventually gets to the ventrical portion and then speeds up again. This occurs because we want contraction to occur at the same rate, not as the same time.
AV Node
skeletal muscle. Only pathway to get electrical impulse to the AV bundle. The propagation is much slower than any other part of the pathway.
AV Bundle (Bundle of His)
Bundle of His - goes from atrial septum to ventricular septum so that the two contract at a similar rate. Allows propogation from the AV node into the ventricular septum. It then splits into a left and right bundle branch. The right gives rise to the moderator band, which gives conducting fibers to the papillary muscles.
Vagus nerve
cell bodies in the medulla. Parasympathetic supply. Will also have sensory fibers coming back to the heart. The postganglionic parasympathetics will have their cell bodies studded on the wall of the heart. Vagus has the cell bodies of the afferent in vagal ganglia. Sensory info here does not reach conscious levels, it is just cardiac reflexes.
Sympathetic
comes from sympathetic chain ganglia. Cell bodies are in thoracic spinal cord. Also has sensory fibers coming back. sensory sympathetics have their cell bodies in dorsal root ganglia. The sensory fibers in the sympathetics that go back to the spinal levels carry sensory info that will reach conscious levels. This seneory info watches the myocardium of the heart to determine if the amount of O2 supplied to the cells is sufficient. So basically they monitor ischemia.
Coronary Sulcus
Also called the atrioventricular sulcus because it separates the right atrium from the right ventricle.
