The Heart Flashcards
What are the different surfaces of the heart and what are they made up out of?
Sternocostal/anterior - RV mainly but also RA and LV.
Diaphragmatic/posterior - Mainly LV but also RV.
R pulmonary - RA.
L pulmonary - LV.
What separates the diaphragmatic surface of the heart from the base?
The coronary sinus
Describe what the base of the heart is composed of and its positioning.
- LA, pulmonary veins and some RA.
- Fixed posteriorly to pericardium at level T6-T9 but when supine it is T5-T8.
Where is the position of the apex of the heart?
The left 5th intercostal space, 8-10cm left of the midline (midclavicular line) but in children it is more superior and lateral
Name the margins of the heart and what they are composed of (important)
Right margin - RA.
Left margin - LV and left auricle.
Inferior margin - RV and LV
Name the 3 external sulci
Coronary sulci, Anterior interventricular sulcus and the posterior interventricular sulcus
Name the function of the coronary sulcus and what runs through it
It separates atria frim ventricles. The right coronary artery, left circumflex artery and coronary sinus runs through it.
What runs through the anterior interventricular sulcus?
Anterior interventricular artery and the great cardiac vein (anterior interventricular vein)
What runs through the posterior interventricular sulcus?
Posterior interventricular artery and the middle cardiac vein (posterior interventricular vein)
Name the three septa of the heart
Interartrial septum, Interventricular septum and the atrioventricular septum (from RA to LV)
Where does the right atrium receive blood from?
SVC, IVC (both have no valves), coronary sinus (60%) and the smallest cardiac veins (40%) that open stright into atrium.
What separates the right atrium from the right auricle?
Internally a muscular ridge called crista terminalis but externally it is sulcus terminalis
What is the fossa ovalis? what is its margin called?
It is on the right side of the interatrial septum and is the site of the foramen ovale in fetus. The margin is called limbus fossae ovalis
What is the valve of inferior vena cava?
It directed blood to the foramen ovale from the placenta in fetus. Meaning oxygenated blood bypassed the under developed lungs
What is the function of the valve of coronary sinus?
It prevents regurgitation of blood when the atrium contracts
Describe features if the right auricle
It has a rough surface formed by pectinate muscles, the function of these is to provide some power of contraction without significantly thickening the cardiac wall
Where is the right ventricle situated?
It sits of the central tendon of the diaphragm
What connect the right ventricle to the pulmonary valve/trunk?
Infundibulum (conus arteriosus)
What is the direction does the blood have to flow in order to pass through the pulmonary trunk?
It flows upwards, backwards and to the left
Name the irregular muscular ridges of the walls of the RV
Trabeculae carnea
Name another muscle in the RV and its function.
Septomarginal trabeculae. It acts as a bridge between the interventricular septum and anterior papillary muscle
What is the function of papillary muscles and how many are there?
They attach to chorda tendinae which attach to the free edges of tricuspid valve cusps. There are three in the RV and two in the LV
What is the function of chorda tendinae?
They prevent the eversion of cusps and therefore prevent regurgitation of blood into the atria during ventricular systole. They can attach to more than one cusp.
What is the direction of blood flow through the tricuspid valve?
Forwards and medially.
