Английский язык для медиков: конспект лекций
Шрифт:
It has a nucleus shaped like a curved rod or band.
Bands normally constitute 0,5-2% of peripheral WBCs; they subsequently mature into definitive neutrophils.
Agranulopoiesis is the process of lymphocyte and monocyte for mation. Lymphocytes develop from bone marrow stem cells (lympho-blasts). Cells develop in bone marrow and seed the secondary lympho-id organs (e. g., tonsils, lymph nodes, spleen). Stem cells for T cells come from bone marrow, develop in the thymus and, subsequently, seed the secondary lym phoid organs.
Promonocytes differentiate from bone marrow stem cells (mono-blasts) and multiply to give rise to monocytes.
Monocytes spend only a short period of time in the marrow before being released into the bloodstream.
Monocytes are transported in the blood but are also found in connective tissues, body cavities and organs.
Outside the blood vessel wall, they are transformed into macropha-ges of the mononuclear phagocyte system.
Thrombopoiesis, or the formation of platelets, occurs in the red bone marrow.
Megakaryoblast is a large basophilic cell that contains a U-shaped or ovoid nucleus with prominent nucleoli. It is the last cell that undergoes mitosis.
Megakaryocytes are the largest of bone marrow cells, with diameters of 50 mm or greater. They undergo 4-5 nuclear divi sions without concomitant cytoplasmic division. As a result, the megakaryocyte is a cell with polylobulated, polyploid nucleus and abundant granules in its cytoplasm. As megakaryocyte maturation proceeds,
A single megakaryocyte can shed (i. e., produce) up to 3,500 platelets.
New words
reticular – сетчатый
sinusoids – синусоиды
granulocytes – гранулоциты
agranulocytes – агранулоциты
active – активный
yellow – желтый
glycoprotein – гликопротеин
erythropoietin – эритропоэтин
large – большой
amount – количество
hemoglobin – гемоглобин
degenerating – вырождение
capable – способный
division – разделение
spherical – сферический
indented – зазубренный
condensed – сжатый
chromatin – хроматин
Запомните следующие застывшие словосочетания.
to play _ chess to play the piano to play _ football to play the guitar out of _ doors
Запомните, что перед обращением артикль опускается.
Е. g. What are you doing, _ girls?
Заполните пропуски, где необходимо.
1. Do you play… piano?
2. There is… big black piano in our living-room.
3. It is at… wall to… left of… door opposite… sideboard.
4. My mother likes to play. piano.
5. She often plays… piano in… evening.
6..boys like to play… football.
7. What do you do in… evening? – I often play… chess with my grandfather.
8. Where are… children? – Oh, they are out of… doors… weather is fine today.
9. They are playing… badminton in… yard.
10. What… games does your sister like to play?
11. She likes to play… tennis.
12. Do you like to play… guitar?
13. What… colour is your guitar?
14. When we want to write… letter, we take… piece of… paper and… pen.
15. We first write our… ad dress and… date in… right-hand corner.
16. Then on… left-hand side we write… greeting.
17. We must not forget to leave… margin on… left-hand side of… page.
18. On… envelope we write… name and address of… person who will receive it.
19. We stick… stamp on… top of right-hand corner.
20. We posted… letter.
Answer the questions.
1. What is hematopoietic tissue composed of?
2. Where is myeloid found?
3. How is red marrow characterized?
4. What does yellow bone marrow contain?
5. Where does hematopoiesis takes place in the human adult?
6. What is erythropoiesis?
7. What is myeloblast?
8. What is band neutrophil?
9. How long are megakaryocytes?
10. How many platelets can a single megakaryocyte shed?
11. Make the sentences of your own using the new words (10 sentences).
12. Find the definite and indefinite articles in the text.
ЛЕКЦИЯ № 18. Arteries
Arteries are classified according to their size, the appearance of their tunica media, or their major function.
Large elastic conducting arteries include the aorta and its large branches. Unstained, they appear yellow due to their high con tent of elastin.
The tunica intima is composed of endothelium and a thin sub jacent connective tissue layer. An internal elastic membrane marks the boundary between the intima and media.
The tunica media is extremely thick in large arteries and con sists of circularly organized, fenestrated sheets of elastic tissue with interspersed smooth muscle cells. These cells are responsi ble for producing elastin and other extracellular matrix com ponents. The outermost elastin sheet is considered as the external elastic membrane, which marks the boundary between the media and the tunica adventitia.