Variant III Ex. 1. Read and translate the text. Pay attention to the vocabulary. What is the arterial system?         …

Variant III

Ex. 1. Read and translate the text. Pay attention to the vocabulary.

What is the arterial system?

         The arteries are the tubes that carry the blood from the heart to the tissue. Their walls are thick, strong, and contain much yellow, elastic tissue, which renders them extensible. When empty they do not collapse. Most arteries occupy protected positions and are straight in their course to reduce friction between the flowing blood and the walls of the arteries. Arteries communicate freely with one another, thus promoting equality of distribution and pressure and making free circulation possible even after a large vessel becomes obliterated. A single large vessel, the pulmonary artery, originates from the right ventricle and another, the aorta, from the left ventricle. These large arteries divide into smaller vessels and then in turn into yet smaller ones. The term “arterial system” is given to the arteries as a whole.

        The pulmonary artery carries dark or venous blood from the right ventricle to the lungs, where it divides into numerous vessels that ramify in the lung tissue.

        The aorta gives passage to the red or arterial blood from the left ventricle. This blood supplies all the organs of the body except the lungs. It is a short vessel that soon divides into thoracic and abdominal branches.

       The common brachiocephalic artery is the thoracic division of the aorta. In the horses it is directed and upward to supply the fore limb, neck, and head.

       The posterior aorta is the abdominal division of the aorta. It arches backward and pierces the diaphragm. It supplies branches to the walls and viscera o that connect the latter with the venulae.

        The veins conduct the blood back to the heart from the tissues. The capacity of the venous system is two or three times that of the arterial.

         The pulmonary veins carry to the left auricle f the abdominal cavity, the body muscles, the udder, the pelvic organs, and the hind limbs.

          The capillaries are the minute continuations of the arterioles the blood which has passed through the lungs and has become oxygenated.

        The anterior vena cava carries to the right auricle the blood returned from the head and neck by the jugular veins and that from the thoracic limbs.

          The posterior vena cava is the largest vein in the body and conveys to the right auricle nearly all the blood from the liver, spleen, intestines, other abdominal and pelvic organs, and the pelvic limbs.

       The lymph vessels are provided with simple valves to prevent a backward flow of the lymph. They all end finally in two main trunks which open into the venous system near the base of the heart.

 extensible [iks'tənsibl] растяжимый

friction ['frik∫ən] трение

pressure ['pre∫ə] давление, сжатие

 aorta [ei'ɒ:tə] аорта

venous ['vi:nəs] венозный

thoracic [θɒ:'ræsik] грудной

abdominal [æb'dɒminəl] брюшной

brachiocephalic ['bra:nt∫iɒu'sefəlik] плечеголовной

fore [fɒ:] носовой

limb [lim] конечность

arch [a:t∫] дуга, изгиб

wall [wɒ:l] стенка, перегородка

viscera ['visərə] внутренние органы

udd ['Λdə] вымя

pelvic ['pelvik] тазовый

hind [haind] задний

anterior ['æn'tiəriə] передний

jugular ['dʒΛgjulə] яремная вена (шейная)

 posterior [pɒs'tiəriə] задний

liver ['livə] печень

 spleen ['spli:n] селезенка

intestine [in'testin] кишечник, кишка

trunk [trΛnk] туловище

Ex. 2. Make a review of the article.

National parks preserve more than species

Study of Costa Rican rainforest shows national parks are more resilient than expected

Date: September 9, 2020

Source: Rice University

Summary:

National parks are safe havens for endangered and threatened species, but an analysis by data scientists finds parks and protected areas can preserve more than species.

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      In a study published online this week in the journal Biotropica, Rice ecologists and data scientists Daniel Gorczynski and Lydia Beaudrot used thousands of camera trap photos to assess the large mammal diversity in the protected rainforest of Costa Rica's Braulio Carrillo National Park.

       In wildlife conservation, diversity often refers to the variety of species in an ecosystem. But ecologists also study functional diversity, the abundance and variation of traits like body size, diet and reproductive rate. Trait diversity can be measured independent of species diversity and provide additional insight about the overall health of an ecosystem.

       In the study, Gorczynski and Beaudrot analyzed more than 4,200 photos of mammals taken in the park between 2007 and 2014 and found the diversity of mammal traits within the park did not decline, despite deforestation that fragmented the forests on more than half of the surrounding private lands.

     "It is a bit of a surprise," said Gorczynski, a Ph.D. student in Rice's Department of Biosciences. "Previous studies in other places have shown that trait diversity is more sensitive to human disturbance than species diversity. Trait diversity can decline more quickly than species diversity, both in cases where species go extinct and where they don't."

      There were no mammal extinctions in Braulio Carrillo during the eight years of the study, and Beaudrot, an assistant professor of biosciences at Rice, said the trait analysis revealed a level of functional redundancy that could allow the park's ecosystem to continue functioning even if some of its mammals go extinct in the future.

     "It's well-established that national parks preserve species, and our results show national parks can be more resilient than expected, at least over the time period we examined," she said.

    Beaudrot said the results are encouraging, but she said it would be a mistake to assume that all national parks are as resilient as Braulio Carrillo.

     "This shows what's possible, but the situation could be very different at other parks or over longer time periods," she said. "We need comparable studies for other parks, other protected areas and nonprotected areas.

      "This is an area where data science can make a difference," she said. "Some of the data needed to make those comparisons are already available."

 

Journal Reference:

1. Daniel Gorczynski, Lydia Beaudrot. Functional diversity and redundancy of tropical forest mammals over time. Biotropica, 2020; DOI: 10.1111/btp.12844

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