Flashcards in Heart, Internal structure, Chambers and valves, Surface anatomy Deck (35):
What forms the right border of the heart?
Which vessels enter the right atrium?
SVC, IVC and the coronary sinuses
How does blood flow through the Right atrium?
through the Tricuspid valve anterior and medially
Describe the structure of the anterior wall of the Right atrium.
trabeculated with musculi pectinati and cristae terminalis
also formed of the auricle
What is the function of the musculi pectinati in the right atrium?
provide some power for atrial contraction
Describe the structure of the posterior wall of the right atrium.
What are the positions of the nodes?
-Smooth. Forms the intratrial septum.
-sino atrial node is close to the opening of the SVC
Atrio ventricular node lies on septum between coronary sinus and tricuspid valve
What surfaces of the heart does the Right ventricle from?
most of the sternocostal (anterior) surface
some of the diaphragmatic surface
What is the flow of blood into and out of the Right ventricle?
Blood flows forwards and medially through the tricuspid valve
outflow is superiorly and posteriorly through the pulmonary valve to the pulmonary trunk+arteries through a smooth infundibulum
Describe the structure of the Right ventricle wall.
Trabeculated with trabeculae carneae, 3 papillary muscles, septomarginal trabecula
What are the three papillary muscles of the right ventricle?
How are they attached?
-anterior, posterior, septal
-attached by chordae tendineae
what is the function of the trabeculae carneae in the right ventricle?
muscular ridges which give power of contraction
Which structure forms the base of the heart?
the left atrium
how many pulmonary veins flow into the Left atrium?
Describe the intratrial wall of the left atrium
slight depression equivalent to the fossa ovalis
long tubular auricle
How does the left ventricle differ from the right?
Why is this?
-Much thicker muscular wall than the right
-to deal with systemic pressure 70-120mmHg
Describe the flow of blood through the Left ventricle.
blood flows superiorly and posteriorly to the pulmonary valve and trunk
Describe the wall of the left ventricle
trabeculated with trabeculae carnea and 2 papillary muscles attached by chordae tendineae
Explain the functional importance of the cardiac skeleton.
Describe its position
-supports valves, myocardium and fibrous rings
- electrically separates the atria and the ventricles by separating atrial and ventricular muscle so there can be no electrical connection between the muscles
What is the only electrical connection between the atria and the ventricles?
Atrioventricular bundle of His
What causes valves to open and close?
Difference in blood pressure
Describe the structure of the tricuspid valve.
3 cusps attached to papillary muscles attached by chordae tendineae
cusps attach to fibrous ring
When in the cardiac cycle does the tricuspid valve open and close?
Closed during systole (ventricular contraction) hence preventing back flow of blood into the atrium.
Open during diastole (atrial contraction)
Describe the structure and location of the pulmonary valve.
3 watch pocket cusps
attached in the root of the pulmonary trunk
When in the cardiac cycle is the pulmonary valve open and closed?
the valve opens during systole, when the pressure in the ventricle is greater than in the pulmonary trunk
the valve is closed during diastole
What is the competence of the Mitral valve?
How many cusps does the mitral valve have?
anterior and posterior
When is the mitral valve open in relation to the cardiac cycle?
open during diastole
Describe the structure of the aortic valve.
Give its location
-3 semi lunar cusps left, right and posterior
-apex of the aorta
State when coronary arteries fill in relation to the cardiac cycle
the aortic valve cusps are closed during diastole to prevent back flow of blood in to the ventricle. This is when the coronary sinuses fill hence filling the coronary arteries
Where are the coronary sinuses which fill the coronary arteries found?
The left and right cusps of the aortic valve, coronary cusps
What is valve incompetence?
How does it occur?
-Cusp eversion during systole and hence back flow of blood occurs
-during an MI if the heart tissue which supplying the papillary muscles of the valve dies then these muscles fail to function
What is the direction of flow of blood in the Tricuspid valve?
Where can you locate it?
-anterior and medially
-4th, 5th interspace
what is the direction of flow of blood through the pulmonary valve?
where is it located?
-superiorly and to the left
-2nd left intercostal space
what is the direction of blood flow through the mitral valve?
Where can you palpate it?
-anteriorly and inferiorly
- towards the apex right side 5th intercostal space mid clavicular line