Month: March 2019

At present, almost all blood vessels (angio- or angiography) are available on live x-rays. The clinic uses various methods of X-ray examination of vessels filled with a radiopaque substance: examination of vessels (angiography), arteries (arteriography), heart and main arteries (angiocardiography), veins (phlebography) and lymphatic vessels (lymphography). In various types of aortography (injection of radiopaque substances, etc.), the aorta can be traced along its entire length and in all its parts: ascending, arc, thoracic and abdominal – with large arteries of the abdominal cavity: splenic, renal, etc. leaving it.

In the left (nipple) oblique position, all parts of the aorta are visible: ascending, arch and descending – to the diaphragm. Bright oval space, limited in front by the shadow of the heart, and above and behind – by the aorta (retrocardial pulmonary field) is called the aortic window. This “window” is narrow or wide, depending on the shape of the chest, the height of the standing of the diaphragm and the position of the heart. In people with a wide and short rib cage, with a high standing of the diaphragm with a horizontal position of the heart, there is a high standing and “unfolded” type of aorta. In this case, both knees of the aorta (ascending and descending) are more distant from each other: the “aortic window” is extended, the aortic arch is relatively straight. In people with a narrow and long rib cage and low standing of the diaphragm with the vertical position of the heart, inverse ratios are observed.

Using an injection of a contrast agent in the abdominal aorta, an image of the abdominal aorta, pars abdominalis aortae, is obtained. Also visible is its bifurcation and the course of both common iliac arteries and their large branches. In the living, due to the intravital tone and mobility of neighboring organs, the abdominal part of the aorta may shift slightly to the right and slightly arcuately bulge to the right, which can be mistaken for pathology, such as pushing the aorta with a tumor.

An x-ray examination of the remaining blood vessels of a living person by injecting (injecting) directly into the vessels of contrasting substances with simultaneous x-rays at the time of injection is called angiography.

When injected into the carotid artery, the common carotid artery is examined, dividing it into the external and internal carotid arteries and branching them in the head and brain (arterial encephalography, or brain angiography).

Introducing contrast agents into the brachial or femoral artery receive the image of large arterial trunks of limbs and their branches.

Selective (selective) arteriography of the arteries of the abdominal cavity allows studying the celiac trunk, mesenteric, renal arteries and their branches. At the same time, the entry of arteries into the gates of organs, in particular the spleen, liver and kidneys, is clearly noticeable. During radiography of the arteries of the parenchymatous organs, not only extraorgan vessels, but also intraorgan vessels are visible.

Oxygen and nutrients are delivered to the fetus from the mother’s blood with the help of the placenta – placental circulation. It occurs as follows. The arterial blood enriched with oxygen and nutrients flows from the mother’s placenta into the umbilical vein, which enters the fetal body in the navel and goes up to the liver, lying down in its left longitudinal sulcus. At the level of the gate of the liver v. The umbilicalis is divided into two branches, one of which immediately flows into the portal vein, and the other, called ductus venosus, rambles along the lower surface of the liver to its posterior margin, where it flows into the trunk of the inferior vena cava.

The fact that one of the branches of the umbilical vein delivers pure arterial blood through the portal vein of the liver gives rise to a relatively large liver; The latter circumstance is associated with the necessary for the developing organism the function of the blood formation of the liver, which prevails in the fetus and decreases after birth. After passing through the liver, blood through the hepatic veins flows into the inferior vena cava.

Thus, all the blood from v. Umbilicalis, either directly (through ductus venosus), or indirectly (through the liver) enters the inferior vena cava, where it is mixed with venous blood flowing through the inferior vena cava inferior from the lower half of the fetus.

Mixed (arterial and venous) blood through the inferior vena cava flows into the right atrium. From the right atrium, it is guided by a valve of the inferior vena cava, valvula venae cavae inferioris, through the foramen ovale (located in the atrial septum) into the left atrium. From the left atrium, the mixed blood enters the left ventricle, then into the aorta, bypassing the pulmonary circulation that is not yet functioning.

In addition to the inferior vena cava, the superior vena cava and the venous (coronary) sinus of the heart flow into the right atrium. Venous blood entering the superior vena cava from the upper half of the body, then enters the right ventricle, and from the latter into the pulmonary trunk. However, due to the fact that the lungs do not function as a respiratory organ, only a small part of the blood enters the lung parenchyma and from there through the pulmonary veins into the left atrium. Most of the blood from the pulmonary trunk along the ductus arteriosus passes into the descending aorta and from there to the viscera and lower extremities. Thus, despite the fact that in general the mixed blood flows through the vessels of the fetus (with the exception of v. Umbilicalis and ductus venosus before its inflow into the inferior vena cava), its quality below the confluence of the ductus arteriosus deteriorates significantly. Consequently, the upper body (head) receives blood richer in oxygen and nutrients. The lower half of the body eats worse than the upper, and lags behind in its development. This explains the relatively small size of the pelvis and lower limbs of the newborn.

The act of birth represents a leap in the development of an organism, during which fundamental qualitative changes of vital processes take place. The developing fetus moves from one environment (uterine cavity with its relatively constant conditions: temperature, humidity, etc.) to another (outside world with its changing conditions), as a result of which the metabolism, as well as the ways of nutrition and respiration, change radically. Instead of nutrients previously obtained through blood, food enters the digestive tract, where it undergoes digestion and absorption, and oxygen begins to flow not from the mother’s blood, but from the outside air due to the inclusion of respiratory organs. All this is reflected in the blood circulation.

At birth, there is a sharp transition from placental circulation to the pulmonary. At the first inhalation and stretching of the lungs with air, the pulmonary vessels greatly expand and fill with blood. Then ductus arteriosus collapses and obliterates during the first 8–10 days, turning into ligamentum arteriosum.

The umbilical artery overgrown during the first 2 – 3 days of life, the umbilical vein – a little later (6 – 7 days). The flow of blood from the right atrium to the left through the oval hole stops immediately after birth, as the left atrium is filled with blood coming from the lungs, and the difference in blood pressure between the right and left atria is equalized. The closure of the oval hole occurs much later than the obliteration of ductus arteriosus, and often the hole persists during the first year of life, and in 1/3 of cases it lasts a lifetime. The described changes are confirmed by X-ray live research.

Deep and superficial veins of the legs. As in the upper limb, the veins of the lower limb are divided into deep and superficial, or subcutaneous, which pass independently of the arteries.

Deep veins of the foot, and the legs are double and accompany the same arteries. V. poplitea, composed of all deep veins of the leg, is a single trunk located in the popliteal fossa posterior and somewhat laterally from the artery of the same name. V. femoralis is solitary, initially located laterally from the artery of the same name, then gradually passes to the back surface of the artery, and even higher – to its medial surface and passes in this position under the inguinal ligament in the lacuna vasorum. Tributaries v. femoralis all double.

Of the subcutaneous veins of the lower extremity, two trunks are the largest: v. saphena magna and v. saphena parva. Vena saphena magna, the large saphenous vein, originates on the dorsal surface of the foot from rete venosum dorsale pedis and arcus venosus dorsalis pedis. Having received several tributaries from the foot, it goes upwards along the medial side of the shin and thigh. In the upper third of the thigh, it is bent on the anteromedialal surface and, lying on the wide fascia, goes to hiatus saphenus. In this place v. saphena magna joins the femoral vein, spreading over the lower horn of the crescent edge. Quite often v. saphena magna is double, and both of its trunk can flow separately into the femoral vein. Of the other subcutaneous inflows of the femoral vein, v. epigastrica superficialis, v. circumflexa ilium superficialis, vv. pudendae externae, accompanying the same arteries. They flow in part directly into the femoral vein, part in v. saphena magna at its confluence with hiatus saphenus. V. saphena parva, small saphenous vein, starts on the lateral side of the dorsal surface of the foot, bends around the bottom and back of the lateral ankle and rises further along the back of the tibia; first, it goes along the lateral edge of the Achilles tendon, and further upwards in the middle of the posterior part of the lower leg, respectively, the groove between the heads m. gastrocnemii. Reaching the lower corner of the popliteal fossa, v. saphena parva flows into the popliteal vein. V. saphena parva is connected by branches with v. saphena magna.

1. In the veins, blood flows in most parts of the body (trunk and limbs) against the direction of gravity and therefore slower than in the arteries. Its balance in the heart is achieved by the fact that the venous bed in its mass is much wider than the arterial one. The greater width of the venous bed compared with the arterial is provided by the following anatomical devices: a large caliber of veins, a large number of them, paired accompaniment of arteries, the presence of veins not accompanying the arteries, a large number of anastomoses and greater density of the venous network, the formation of venous plexuses and sinuses, the presence of portal system in the liver. Because of this, venous blood flows to the heart through three large vessels (two hollow veins and the coronary sinus, not to mention the small veins of the heart), while the about one pulmonary trunk.

2. The deep veins accompanying the arteries, i.e., the vein satellites (venae commitantes), in their distribution obey the same laws as the arteries they accompany (see “Regularities in the distribution of arteries”), while most of them accompany the arteries in double number. Paired veins are found mainly where the venous outflow is most difficult, that is, in the extremities, since such a structure has developed even in four-legged animals, in which both pairs of extremities occupy a sheer position and the torso is horizontal.

3. Accordingly, the grouping of the whole body around the nervous system deep veins are located along the nerve tube and nerves. Thus, parallel to the spinal cord is the inferior vena cava, and each segment of the spinal cord corresponds to segmental veins, for example, vv. lumbales and rr. spinales.

4. According to the division of the body into the organs of plant and animal life, the veins are divided into parietal – from the walls of the body cavities and visceral – from their contents, i.e. from the inside.

5. Most of the veins are located on the principle of bilateral symmetry.

6. The veins of the trunk walls retain a segmental structure.

7. Deep veins go along with other parts of the vascular system – arteries and lymphatic vessels, as well as nerves, participating in the formation of neurovascular bundles.

8. Veins also go according to the skeleton. So, along the spine is the inferior vena cava, along the ribs – intercostal veins, along the bones of the limbs – the veins of the same name: shoulder, radial, ulnar, femoral, etc.

9. The veins travel along the shortest distance, that is, approximately in a straight line connecting the place of origin of this vein to its confluence.

10. Superficial veins lying under the skin accompany the skin nerves. A significant part of the superficial veins form subcutaneous venous networks that have no relation to either the nerves or the arteries.

11. Venous plexuses are found mainly on the internal organs, which change their volume, but are located in cavities with unyielding walls, and facilitate the outflow of venous blood with an increase in organs and compression of their walls. This explains the abundance of venous plexuses around the pelvic organs (bladder, uterus, rectum), in the spinal canal, where the pressure of the cerebrospinal fluid constantly fluctuates, and in other similar places.

12. In the cranial cavity, where the slightest obstruction of the venous outflow affects the brain function, there are, in addition to the veins, special devices – the venous sinuses with unyielding walls formed by a hard shell. Therefore, they lie mainly at the site of attachment of durae matris processes to the bones of the skull (sutures of the integumentary bones and sinous bones of the sinuses).

13. Special devices include veins located in the channels diploe – venae diploicae.

The roots of the portal vein anastomose with the roots of the veins belonging to the systems of the upper and lower hollow veins, forming the so-called portocaval anastomoses, which have practical significance. If we compare the abdominal cavity with a cube, then these anastomoses will be located on all its sides, namely:

1. Upstairs, in the esophagus pars abdominalis, between the roots v. gastricae sinistrae, which flows into the portal vein, and vv. esophageae flowing into vv. azygos et hemyazygos and further in v. cava superior.

2. Down in the lower part of the rectum, between v. rectalis superior, flowing through v. mesenteria inferior to the portal vein, and vv. rectales media (tributary v. iliaca interna) et inferior (tributary v. pudenda interna), flowing into v. iliaca interna, and further v. iliaca communis – from system v. cava inferior.

3. In front, in the navel, where their tributaries anastomose vv. paraumbilicales, going in the thickness lig. teres hepatis to portal vein, v. epigastrica superior from system v. cava superior (v. thoracica interna, v. brachiocephalica) and v. epigastrica inferior of system v. cava inferior (v. iliaca externa, v. iliaca communis). Portokavalny and caval caval anastomoses are obtained, having a meaning of a circulating pathway of blood outflow from the portal vein system in the event of obstructions in the liver (cirrhosis). In these cases, the veins around the navel expand and acquire a characteristic appearance (“the head of a jellyfish”).

4. Posteriorly, in the lumbar region, between the roots of the veins of the mesoperitoneal colon (from the portal vein system) and parietal vv. lumbales (from the system v. cava inferior).

5. In addition, there is a caval caval anastomosis between the roots vv on the posterior abdominal wall. lumbales (from the v. cava inferior system) that are associated with the v. lumbalis ascendens, which is the beginning of vv. azygos (right) et hemiazygos (left) (from the system v. cava superior).

6. Cavo-caval anastomosis between vv. lumbales and intervertebral veins, which in the neck are the roots of the superior vena cava.

V. iliaca interna, internal iliac vein, in the form of a short but thick trunk located behind the artery of the same name. The tributaries, from which the internal iliac vein is composed, correspond to the arterial branches of the same name, usually outside the pelvis, these tributaries are in double number, and they are single in the pelvic cavity. In the area of ​​the tributaries of the internal iliac vein, a number of venous plexuses are formed, which anastomose among themselves.

1. Plexus venosus sacralis is composed of the sacral veins – lateral and median.

2. Plexus venosus rectalis – plexus in the walls of the rectum. There are three plexuses: submucosal, subfascial and subcutaneous. The submucosal, or internal, venous plexus, plexus rectalis internus, in the area of ​​the lower ends of the columnae anales represents a series of venous nodules arranged in a ring. The diverting veins of this plexus perforate the muscular layer of the intestine and merge with the veins of the subfascial, or external, plexus, plexus rectalis externus. From the last go v. rectalis superior and vv. rectales mediae, accompanying co-arteries. The first through the inferior mesenteric vein is poured into the portal vein system, the second – into the system of the inferior vena cava through the internal iliac vein. In the area of ​​the external sphincter of the anus, a third plexus is formed — subcutaneous, plexus subcutaneus ani, from which the vv. rectales inferiores flowing into v. pudenda interna.

3. Plexus venosus vesicalis is located in the area of ​​the bottom of the bladder; through vv. vesicales blood is poured from this plexus into the internal iliac vein.

4. Plexus venosus prostaticus is located between the bladder and the pubic symphysis, encompassing the male prostate gland and seminal vesicles. Unpaired v. Merges into plexus venosus prostaticus. dorsalis penis. In a woman, this vein corresponds to v. dorsalis clitoridis.

5. Plexus venosus uterinus and plexus venosus vaginalis women are located in the wide ligaments on the sides of the uterus and further down the side walls of the vagina; blood from them through the ovarian vein (plexus pampiniformis), mainly through v. uterina, enters the internal iliac vein.