Valvula

VALVULA (diminutive of Latin valvae—shutters, flaps, doors), a valve, a flap. The Greeks and Romans knew of no valves other than those of the heart, and called them hymenes; the term "valvula" was borrowed by Bauhin from the well-known 17th-century German linguist J. Benedictus. At present, the term V. is widespread in anatomical terminology and is used to denote very different formations, of which the following can be noted: 1. V. atrio-ventricularis (bicuspidalis s. mitralis and tricuspidalis)—the bicuspid, or mitral, valve in the form of an endocardial fold between the atrium and ventricle of the left half of the heart, and the tricuspid valve of the right. 2. V. Bauhini s. coli—the Bauhin valve (ileocecal valve), formed by two folds of the mucous membrane of the ileum, protruding into the large intestine (see Cecum). 3. V. Eustachii s. venae cavae (inferioris)—the Eustachian valve, a fold of the endocardium in the right atrium that undergoes reduction after birth, stretching from the lower edge of the orifice of the inferior vena cava to the lower edge of the oval foramen in the septum between both atria and directing blood into it from the vein. 4. V. foraminis ovalis—the sickle-shaped valve, not completely closing the oval foramen, protruding into the right atrium, which after birth adheres and forms the membranous floor of the oval fossa. 5. V. Heisteri (spiralis)—a spiral fold of the mucous membrane in the neck of the gallbladder. 6. V. pylori—the fold of the pylorus of the stomach, for the most part ring-shaped, formed as a result of the layer of circular musculature located beneath it. 7. Vv. semilunares aortae (and a. pulmonalis)—the semilunar pocket-shaped valves of the aorta and pulmonary artery, three at the beginning of the named arteries, somewhat thickened at the line of their attachment; in the middle of the free edge of each of them there is a nodular thickening (nodulus Arantii), which contributes to the complete closure of the valves. 8. V. sinus coronarii cordis (Thebesii)—the Thebesian valve, semilunar, often reticularly perforated, located in the right atrium at the mouth of the coronary sinus, the main collector of the cardiac veins. 9. Vv. venarum—venous valves, pocket-shaped folds of the inner lining of such veins that are subject to compression; they are arranged in pairs (rarely even in threes) or singly (at the places of inflow). Many of the valves that exist in the fetal period are reduced (for example, in the portal vein). They are especially numerous in the cutaneous and deep veins of the limbs. They are absent in the veins of the skull, bones, the umbilical vein, and the pulmonary veins. Venous valves, when veins are compressed, facilitate the pushing of blood into sections located closer to the heart; when stretched, they draw in blood from sections located further from the heart.

P. Karuain. VALVULOTOMY (valvulotomia), an operation to eliminate stenosis of heart valves. Through a small incision in the wall of the ventricle or aorta, a scalpel or a special instrument (a so-called valvulotome, proposed by Americans) is introduced, with which the corresponding

Figure 1. Coxa valga.

valve is incised (blindly). It has been performed on humans only twice (Tuffier, Doyen), in one case with a successful outcome. It has been experimentally developed by many authors (Cushing, Carrel, Jeger, Tuffier, and Dmitriev). For surgical access to the heart, see Heart.