THE HEART
FARROKH S SADR MD FACS
ON THIS PAGE I WILL BRIEFLY DISCUSS THE ANATOMY, TERMINOLOGY AND PHYSIOLOGY OF THE HEART.
This is long axis cross section of the heart .
The far left cartoon shows the anatomy of the heart , 4 chambers and 4 valves of the heart are marked in this picture.
The two lower chambers are called ventricles.The left (lt)ventricle is the main pumping chambers of the heart.The lt ventricular wall muscle is thicker than the rt ventricle.The TRICUSPID and MITRAL valves connect the rt and the lt ventricles to the rt and the lt atria (pleural of atrium) respectively.The tricuspid and mitral valves control the flow of blood from atria to the ventrcles.
The cartoon demonstrate two cup shape valves,the PULMONIC and the AORTIC valves,which control the rt and lt ventrcular blood flow to the lungs and the aorta.
The heart valves are made up of two or three fibrous tissue flaps called leaflets,overlapping leaflets of TRICSPID and MITRAL valve between each atrium and ventricle are helped to function by FIBROUS CORDS (cordae tendinae)that connect them to the specialized muscle of ventricular wall called pappilary muscle.
The cup shape AORTIC and PULMONARY valves do not receive cordae support from nearby heart muscle.
HOW DO HEART VALVES WORK ?
The cartoons demonstrate the heart size increases and decreases during the filling (diastole)(pronounced die-astoly) and emptying on contraction or systole(sys-toli) of the ventricles , during ventricular filling to capacity (diastole) the TRICUSPID and the MITRAL valves are open ,the Aortic and the Pulmonic valves are closed ,during the SYSTOLE while the rt and the lt ventricles are contracing the tricuspid and the MITRAL valves are closed inorder to prevent regurgitation of the blood through the tricuspid and the MITRAL valve back in to the respective atria.
You wonder why each side of the heart has two pumping chambers (atrium and ventricle)?.
The atria serves as a "booster pump" that increases the filling of the ventricle.
The upper (or "priming") pumping chamber on the left side of the heart. The left atrium sits above the mitral valve and gently forces blood across the mitral valve into the left ventricle. This actions "primes" the lower pumping chamber to improve efficiency. At the same time, the left atrium provides a temporary storage site for blood returning from the lungs during the time that the left ventricle is actually squeezing.
You can compare this to a strong spring, and imagine that the heart muscle is made up of tiny little "springs" known as ACTIN and MYOSIN. Within reasonable limits, the more you stretch a
spring, the more vigorously will be its contraction or recoil.
In medical terms, this is known as "Frank-Starling's" law.The heart muscles and the valves dysfunctions will volum over load your atria or ventricles and causes numerous VALVULAR HEART DISEASE.I invite you to visit the Aortic Valve, Mitral Valve diseases.
Mitral Valve Repair.
THESE MEDICAL TERMINOLOGY ARE REFERENCED FROM HEART SURGERY FORUM WEB.
ALMOST A WHISPER©YANI
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