Almost all parts of the body are va

Almost all parts of the body are vascular. Minute and very close-set canals, which have opened into one another traverse them and constitute a small-meshed network. The canals or rather tubes have distinct but very delicate walls. The walls contain a membrane that includes a number of thin epithelial cells, which are bound (связаны) together at their edges. There is a small oval nucleus in each of these cells. These tubes are the blood capillaries. They vary in diameter from 7 to 12 μηι. But there are certain parts of the body in which these blood capillaries

have been absent. These are the epidermis and epithelium, the nails and hairs, the substance of the teeth and the transparent cornea of the eye.

Tiny rings of muscles, precapillary sphincters, regulate the flow of blood into capillaries. The question of nervous control of the precapillary sphincters still remains the subject of the study.

The capillary tubes contain the red fluid, blood. They join on opposite sides and form larger tubes, with thicker walls, which are the smallest arteries on the one side, and veins, on the other. These again join on to larger arteries and veins, which ultimately communicate by a few principal arterial and venous trunks with the heart. The mere fact that the walls of these vessels are thicker than those of the capillaries constitutes an important difference between the capillaries and the small arteries and veins.

The most important difference between these vessels and the capillaries, however, is that their walls are not only thicker, but also more complex. They have got several coats, one, at least, of which has been muscular. The number and even nature of these coats differ according to the size because the vessels are not the same in the veins as in arteries, though the smallest veins and arteries resemble each other.

The venous system starts with the venules into which the capillaries empty. Small veins join and form larger ones. The larger veins join and form the venae cavae. The superior vena cava collects the blood from the head, neck, arms, and thorax, and the inferior vena cava, from the legs and abdomen. Both empty into the right atrium.

Pressure in the venous system is low. In the vein at the level of the heart the pressure would be more than 5-7 mm Hg.1 It is evident that in the erect position blood that returns to the heart from the feet has to overcome the force of gravity through a distance of about 4 ft.2 Veins, probably because of the low blood pressure and the absence of pulse waves, are in comparison to arteries, relatively immune to disease. Phlebitis sometimes occurs; this is the formaiton of blood clots within veins because of some infectious process in their walls.

Результаты (английский) 1:

Almost all parts of the body are options. Minute and very close-set:, which have opened into one another traverse them and a special small-meshed network. The: or rather tubes have distinct but very delicate walls. The walls contain a membrane that includes a number of thin epithelial cells, which are bound (connected) together at their edges. There is a small oval nucleus in each of these cells. These tubes are the blood capillaries. They vary in diameter from 7 to 12 μηι. But there are certain parts of the body in which these blood capillarieshave been absent. These are the epidermis and epithelium, the nails and hairs, the substance of the teeth and the transparent cornea of the eye.Tiny rings of muscles, precapillary sphincters, regulate the flow of blood into the capillaries. The question of "nervous control of the precapillary sphincters still remains the subject of the study.The capillary tubes contain the red fluid, blood. They join on opposite sides and form larger tubes, with thicker walls, which are the smallest arteries on the one side, and veins, on the other. These again to join on larger arteries and veins, which ultimately communicate by a few principal arterial and venous trunks group with the heart. The mere fact that the walls of these vessels are thicker than those of the capillaries constitutes an important difference between the capillaries and the small arteries and veins.The most important difference between these vessels and the capillaries, however, is that their walls are not only thicker, but also more complex. They have got several coats, one, at least, of which has been muscular. The number and even the nature of these coats differ according to the size because the vessels are not the same in the veins as in arteries, though the smallest veins and arteries resemble each other.The venous system starts with the venules into which the capillaries empty. Small veins join and form larger ones. The larger veins join and form the venae cavae. The superior vena cava collects the blood from the head, neck, arms, and thorax, and the inferior vena cava, from the legs and abdomen. Both empty into the right atrium.Pressure in the venous system is low. In the vein at the level of the heart, the pressure would be more than 5-7 mm Hg. 1 It is evident that in the erect position blood that returns to the heart from the feet has to overcome the force of gravity through a distance of about 4 ft. 2 Veins, probably because of the low blood pressure and the absence of pulse waves , are in comparison to the arteries, relatively immune to disease. Phlebitis occurs sometimes; This is the formaiton of blood clots within veins because of some infectious process in their walls.

Результаты (английский) 2:

Almost all parts of the body are vascular. Minute and very close-set canals, which have opened into one another traverse them and constitute a small-meshed network. The canals or rather tubes have distinct but very delicate walls. The walls contain a membrane that includes a number of thin epithelial cells, which are bound (connected) together at their edges. There is a small oval nucleus in each of these cells. These tubes are the blood capillaries. They vary in diameter from 7 to 12 μηι. There are certain But parts of the body in which these blood capillaries have been absent. Are the epidermis These and epithelium, the nails and hairs, the substance of the teeth and the transparent cornea of the eye. Tiny rings of muscles, precapillary sphincters, regulate the flow of blood into capillaries. Question of nervous The control of the precapillary sphincters still remains the subject of the study. The capillary tubes contain the red fluid, blood. They join on opposite sides and form larger tubes, with thicker walls, which are the smallest arteries on the one side, and veins, on the other. These again join on to larger arteries and veins, which ultimately communicate by a few principal arterial and venous trunks with the heart. The mere fact that the walls of these vessels are thicker than those of the capillaries constitutes an important difference between the capillaries and the small arteries and veins. The most important difference between these vessels and the capillaries, however, is that their walls are not only thicker, but also more complex. They have got several coats, one, at least, of which has been muscular. The number and even nature of these coats differ according to the size because the vessels are not the same in the veins as in arteries, though the smallest veins and arteries resemble each other. The venous system starts with the venules into which the capillaries empty. Small veins join and form larger ones. The larger veins join and form the venae cavae. The superior vena cava collects the blood from the head, neck, arms, and thorax, and the inferior vena cava, from the legs and abdomen. Into the empty Both right atrium. Pressure in the venous system is low. In the vein at the level of the heart the pressure would be more than 5-7 mm Hg.1 It is evident that in the erect position blood that returns to the heart from the feet has to overcome the force of gravity through a distance of about 4 ft.2 Veins, probably because of the low blood pressure and the absence of pulse waves, are in comparison to arteries, relatively immune to disease. Phlebitis sometimes occurs; this is the formaiton of blood clots within veins because of some infectious process in their walls.

Результаты (английский) 3:

almost all parts of the body are vascular. minute and very close - set palace, which have opened into one another traverse them and constitute a small meshed network. the palace or rather tubes have distinct but very delicate walls. the walls contain a membrane that includes a number of thin take cells, which are bound (associated) together at the first floor.there is a small oval nucleus in each of these cells. these tubes are the blood capillaries. they vary in diameter from 7 to 12 μηι. but there are certain parts of the body in which the blood capillaries

have been absent. these are the epidermis and epithelium, the nails and hairs, the substance of the teeth and the transparent cornea of the eye.

tiny rings of muscles,precapillary sphincters, regulate the flow of blood into capillaries. the question of nervous control of the precapillary sphincters still remains the subject of the study.

capillary tubes contain the red fluid and blood. the research on opposite sides and form larger tubes, with thicker walls, which are the arteries making facilities, on the one side, and veins, on the other.these are skills on to larger arteries and veins, which includes except by a few principal arterial and venous trunks with the heart. the mere fact that the walls of these vessels are thicker than those of the capillaries constitutes an important difference between the capillaries and the small arteries and veins.

the most important difference between these vessels and the capillaries,however, is that their walls are not only thicker, but also more complex. they have got several coats, one, at least, of which has been muscular. but the number and nature of these coats differ according to the size because the vessels are not the same in the veins as in arteries, though the veins making facilities and arteries resemble each other.

the venous system starts with the venules into which the capillaries empty. small veins join and form larger ones. the larger veins join and form the venae cavae. the superior cava vena collects the blood from the head, neck, arms, and thorax, and the inferior vena cava, from the legs and abdomen. both empty into the right atrium.

pressure in the venous system is low.