Valves of the heart

The heart is located in then ventral cavity, inside the thoracic cavity. To pump blood efficiently the heart needs valves that ensure a predominantly one-way flow. Blood flows through the heart in one direction - from atria to the ventricle and out the great arteries - leaving the superior aspect of the heart. This one-way traffic is enforced by four heart valves.

The four main valves in the heart are:
The two atrioventricular (AV) valves, the mitral valve (bicuspid valve), and the tricuspid valve, which are between the upper atria and the lower ventricles.

The two semilunar (SL) valves, the aortic valve and the pulmonary valve, which are in the arteries leaving the heart.

Each atrioventricular valves consist of a flap of connective tissue that is covered on both sides by endocardium and is devoid of blood vessels. The atrial surface of the flap, is smooth, the chord tendineae arise from its free margins and inferior surface. The atrioventricular (AV) valves regulate the openings between the atria and ventricles, the right AV tricuspid vale has three cups and the left AV bicuspid have has two.

The valves of the pulmonary trunk and aorta each consist of three nearly equally sized valves the semilunar cusps, which are formed by folds of endocardium. The semilunar valves regulate the flow of blood form the ventricles onto the great arteries. Aortic and pulmonary valves are of very similar structure to atrioventricular valves, but they do nor possess chord tendineae.

The texture of valves is as smooth as silk, thus blood particles and bacteria do not adhere to them.
Valves of the heart

What is stroke?

Stroke has been recognized for thousands of years and is the third most common cause of death after heart disease and cancer in developed countries.

Approximately 550,000 people suffer a stroke each year nearly 150, 000 people die from stroke, and about 3 million stroke survivors have varying degrees of residual neurological impairment.

It is a disease of the brain and is caused by a blockage or rupture of the essential blood supply that results in an acute clinical syndrome lasting more than 24 hours.

There is clear neurological deficit and some degree of permanent brain damage.

Based on the blood vessel involved the symptoms are different and specific and often help pinpoint the exact location of the lesion in the central nervous system.

The two most common types of stroke are:
*Ischemic – blockage
*Hemorrhagic (intracerebral) – bleeding

While some risk factors for ischemic and hemorrhagic stroke are different, the following risk factors are applicable to 90% of strokes:
*High blood pressure
*Smoking
*Waist to hip ratio
*Unhealthy diet
*Consuming too much alcohol
What is stroke?

Atrium of the heart

The four chambers in the heart can be segregated into the left and the right side, each containing an atrium and a ventricle.

The right atrium lies anterior to the left atrium, and the right ventricle lies anterior to the left ventricle. The part of the atrium posterior to the ridge is smooth walled, whereas the interior of the auricle is roughened by bundles of muscle fibers, the musculi pectinati.

The right atrium consists of a main cavity and a small out pouching, the auricle.

The role of the right atrium and ventricle is to collect oxygen-poor blood from the body and pump it to the lungs. The role of the left atrium and ventricle is to collect oxygen-rich blood from the lungs and pump it throughout the body.

Within each side, the atrium is a site for the collection of blood, before pumping it to the ventricle.

Right atrium is larger than the left atrium but has a thinners wall and its sinus venarum between two vena cavae is separated from the atrium proper by the crista terminalis. Right atrium has at right atrial pressure that is normally slightly lower than left atrial pressure.

Left atrium is smaller and has thicker walls than the right atrium, but its wall are smooth, except for a few pectinate muscles in the auricle. The left atrium is situated behind the right atrium an forms the greater part of the base or the posterior surface of the heart.
Atrium of the heart

What is tricuspid insufficiency?

A mild degree of tricuspid insufficiency is found in up to 80% of patients. It is refers to an abnormal flow of blood from the right ventricle to the right atrium. The most common cause of tricuspid insufficiency is right ventricular failure.

Tricuspid insufficiency or tricuspid regurgitation or tricuspid incompetence is a common incidental echocardiographic finding and is readily detected using color-flow Doppler imaging.

In adolescents and young adults, most cases of tricuspid insufficiency are the result of congenital cardiac abnormalities.

In patients with rheumatic heart disease tricuspid insufficiency rarely occurs alone; it is usually associated with mitral or aortic valve disease.

The symptoms of tricuspid insufficiency are those of right-sided heart failure and include ascites, edema an occasionally right upper quadrant pain.
What is tricuspid insufficiency?