SCIENCE AND INNOVATION IN THE
EDUCATION SYSTEM
International scientific-online conference
120
SQUAMOUS METAPLASIA IN THE RESPIRATORY TRACT
Ибрагимова З.Ж.
Ферганский медицинский институт
общественного здоровья
Телефон:+998(90) 164 29 21
https://doi.org/10.5281/zenodo.12514279
Abstract:
This thesis discusses squamous cell metaplasia as a
preneoplastic change in bronchial epithelium that occurs in response to toxic
exposures, especially from cigarette smoke. The process of epithelial change
from multi-row ciliated columnar to multilayered squamous epithelium and the
associated consequences, such as chronic bronchitis and risk of lung cancer,
especially in smokers, are described. The text also emphasizes the importance of
preventing and addressing factors contributing to these changes to prevent
possible malignant transformation of the epithelium.
Keywords:
respiratory mucosa
, columnar-to-squamous metaplasia,
squamous metaplasia, bronchiectasis, squamous cell carcinoma.
In human respiratory mucosa, ciliated pseudostratified
columnar epithelium
may change to stratified squamous epithelium. This change from columnar to
squamous epithelium
epithelium is referred as columnar-to-squamous
metaplasia or simply the squamous metaplasia. Epithelial alterations of this kind
are reversible and are characterized by
change from one type of fully
differentiated adult cell to a different type of adult cell. A given mature cell does
not change
to another type of mature cell; rather, basal cell proliferation
gives
rise to the new differentiated cell type. These cellular
changes are considered to
be controlled and adaptive.
Squamous metaplasia is a normal occurrence on the
rounded, more
exposed portions of the turbinates, on the
vocal folds, and in certain other
regions.
Changes in the character of the respiratory epithelium may, however,
occur in other ciliated epithelial sites when the pattern of airflow is altered or
when forceful airflow occurs, as in chronic coughing. Typically, in chronic
bronchitis and bronchiectasis, the respiratory epithelium changes in certain
regions to a stratified squamous form. The altered epithelium is more resistant
to physical stress and insult, but it is less effective functionally. In smokers, a
similar epithelial change occurs. Initially, the cilia on ciliated cells lose their
synchronous beating pattern as a result of noxious elements in smoke. As a
SCIENCE AND INNOVATION IN THE
EDUCATION SYSTEM
International scientific-online conference
121
result, removal of mucus is impaired. To compensate, the individual begins to
cough, thereby facilitating the expulsion of accumulated mucus in the airway,
particularly in the trachea. With time, the number of ciliated cells decreases
because of chronic coughing. This reduction in ciliated cells further impairs the
normal epithelium and results in its replacement with stratified squamous
epithelium at affected sites in the airway. If factors (i.e., tobacco smoking) that
predispose to squamous metaplasia are not eliminated, the metaplastic
epithelium may undergo malignant transformation. Therefore, one of the two
most common forms of cancer in the respiratory tract, the squamous cell
carcinoma, has its origin from the squamous metaplastic cells.
References:
1. Бахтин А. А., Туманова Е. Л. Экспрессия цитокератинов реактивно
измененного цилиндрического реснитчатого эпителия синоназального
тракта
при
хронических
воспалительных
процессах
//Научно-
практический рецензируемый журнал Клиническая и экспериментальная
морфология. – 2023. – Т. 12. – №. 2. – С. 14-24.
3. Jalolidinovna I. Z. Onkologik kasalliklarda limfa tugunlarida morfofunksional
o'zgarishlar //Scientific Impulse. – 2022. – Т. 1. – №. 5. – С. 952-955.
4. Histology: a text and atlas: with correlated cell and molecular biology/Michael
H. Ross, Wojciech Pawlina.—6th ed.
6. TISHABAEVA N. A., IBRAGIMOVA Z. J., MIRZAJONOVA S. A. Iron deficiency
anemia as an actual problem in medical practice //THEORETICAL & APPLIED
SCIENCE Учредители: Теоретическая и прикладная наука, (4). – 2022. – С.
653-656.
