Morphology of heart valves has long attracted the attention of researchers. Violation of the architectonics or operation of any part of the valvular apparatus leads to a violation of the closing function of the valve and the pumping activity of the heart as a whole.
General principles of the structure of atrioventricular septa
Valve valves contain the annulus, leaflets, chordae, and papillary muscles.
Valve rings are a fibrous formation with the inclusion of muscle elements, covered from the inside by the endocardium. The leaflets of the valves are covered with endothelium and have a layered structure.
There are 3 layers in the direction from the atrial to the ventricular surface:
- Spongy.
- Fibrous.
- Ventricular.
The leaflet is based on a fibrous plate, which comes from the fibrous ring. Valve valves, or rather their spongy layer, is narrow, has many elastic fibers in the connective tissue, which are concentrated mainly along the free edge of the leaflet. Comparatively more elastic fibers in the petals of the bicuspid valve than in the tricuspid valve.
Bthe ventricular layer is dominated by collagen fibers.
Valve surfaces
Valve valves have two surfaces - atrial and ventricular, and two edges - attached and free. The area of the atrioventricular valves in male hearts is greater than the area of the same valves in female organs. The tricuspid valve is approximately 25% larger than the bicuspid valve.
Papillary muscles with tendon chords form the subvalvular apparatus of the heart. The chords are attached to the valves. Their length and thickness reaches its maximum by the age of 35-40.
Butterfly valve
The number of flaps (petals) is from 2 to 6. Main:
- front, often one, sometimes divided into two parts;
- rear.
They are always big.
The anterior leaflet is triangular in shape, attached to the superior medial third, the posterior leaflet to the rest of the said valve, it is distinguished by a rectangular shape. Both have a smooth basal and rough apical zones separated by a ridge.
The anterior lobe of the mitral valve is functionally the main one, it is more mobile, during systole it bears the main load, since it experiences the pressure of the bulk of the blood expelled by the ventricle.
Rear is more involved in closing the valve. Its functional significance is less. The valve leaflets are fixed with chords to the papillary muscles.
Tendin chords:
weave from the ventricular side of the valves into roughzones, each split into three thinner strands
To the anterior lobe, which has a 2-leaf valve, 5-10 chords are attached from the papillary muscles, to the posterior lobe - 10-20, sometimes 20-30 tendon filaments. Left atrio-ventricular opening on the level of the annulus is slightly oval.
3-leaf valve
Regarding the number of valves (petals) and their size in this structure, there is also no consensus. It is generally accepted that it consists of 3 leaflets and a different number of segments or intermediate valves. With age, the number of petals increases due to the splitting of the main plates into smaller ones.
The leaflets of the right atrioventricular valve are a duplicate of the endocardium that lines the right atrium and ventricle.
The right ventricle, corresponding to 3 valves, usually has three groups of papillary muscles. They come from the myocardium of the right ventricle (the anterior is the most powerful, then the posterior and septal). The number of these muscles, size and shape of people are not the same. Each papillary muscle sends 2-4 chords, which, branching, attach to the lower surface and edges of the valve cusps. Small intermediate valves attach to the wall of the ventricle.
Heart valve research is fundamental.
In recent years, the issues of blood supply to the valves and their ontogeny have been clarified.
Thus, this article discusses the issue of the structure of the heartvalves, including two- and three-leaf. This information will be useful to students of medical institutions, as well as those who only wish to enter this speci alty. Moreover, students studying biology and anatomy will also be very interested in information about what valve valves are.
