Monocytes possess an eccentric U-shaped or kidney-shaped nucleus. The cytoplasm has a ground-glass appearance and fine azurophi-lic granules.
Their nuclei stain lighter than lymphocyte nuclei because of their loosely arranged chromatin.
Monocytes are the precursors for members of the mononuclear phagocyte system, including tissue macrophages (histiocytes), osteoclasts, alveolar macrophages, and Kupffer cells of the liver.
Platelets (thromboplastids) are 2-3 mm in diameter.
They are a nuclear, membrane-bound cellular fragments derived by cytoplasmic fragmentation of giant cells, called megakaryocytes, in the bone marrow.
They have a short life span of approximately 10 days.
There are normally 150 000-400 000 platelets per mm>3 of blood. Ultrastructurally, platelets contain two portions: a peripheral, light-staining hyalomere that sends out fine cytoplasmic processes, and a central, dark-staining granulomere that con tains mitochondria, va-cuoles, glycogen granules, and granules. Platelets seal minute breaks in blood vessels and maintain endothelial integrity by adhering to the damaged vessel in a process known as platelet aggregation. Platelets are able to form a plug at the rupture site of a vessel because their mem brane permits them to agglutinate and adhere to surfaces.
Platelets aggregate to set up the cascade of enzymatic reac tions that convert fibrinogen into the fibrin fibers that make up the clot.
New words
blood – кровь
to be considered – рассматриваться
modified – измененный
mesodermal – мезодермальный
erythrocytes – эритроциты
leukocytes – лейкоциты
platelets – тромбоциты
fibrous proteins – волокнистые белки
cellular – клеточный
elements – элементы
immune – иммунный
humoral – гуморальный
important – важный
trans porting – транспортировка
carbon – углерод
dioxid – диоксид
to contain – содержать
circular – проспект
dark-stained – запятнанный
nuclei – ядра
scanty – скудный
precursors – предшественники
short – короткий
life – жизнь
span – промежуток
approximately – приблизительно
peripheral – периферийный
light-staining – легкое окрашивание
to aggregate – настраивать
to set up – устанавливать
Вставьте артикль, где необходимо.
1. He has… small family.
2. He has… father and… mother.
3. He has no… brother, but he has… sister.
4. His sister is… pupil.
5. She is… good girl, and she had… many Russian books, but she has no… English hooks.
6. There is… writing-desk in… room… writing-desk is good.
7. There is… lamp on.writing desk.
8. My uncle has… large family. They are six in… family.
9. My father is… engineer.
10. He works at… big factory.
11. We have… good library.
12. Our books are in… big bookcase.
13. In your sister… married?
14. What do you do after… breakfast?
15. I go to… school.
16. When do you come… home?
17. I come… home at… half past two.
18. Do you like to watch TV in… evening?
19. There is… paper on… writ ing-desk.
20. My… books and… exercise-books arc on… writing-desk, too.
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1. What… colour is your new… hat?
2. It is… white.
3. Is there… refrigerator in your… kitchen?