Cellular Response To Streas And Injury Flashcards
(35 cards)
reversible functional
and structural responses to more severe
physiologic stresses and some
pathologic stimuli
Adaptation
Adaptations may be
Pathological or physiological
Types of adaptive responses
an increase in the size of cells=
HYPERTROPHY
– an increase in their number=
HYPERPLASIA
– a decrease in the size and metabolic activity
of cells= ATROPHY
– a change in the phenotype of cells=
METAPLASIA
Hypertrophy is the result of
Increased production of cellular proteins
Three basic steps in
the molecular pathogenesis of cardiac
hypertrophy
mechanical sensors (that are
triggered by increased work load)
– Growth factors (including TGF-β, insulin-like
growth factor-1 [IGF-1], fibroblast growth factor)
– Vasoactive agents (such as α-adrenergic agonists,
endothelin-1, and angiotensin II)
Cardiac hypertrophy results in
Loss of myocardial fibers
Myocyte death
Cardiac failure
Barbiturates
Show hypertrophy in SER
Physiologic Hyperplasia
1) • Physiologic hyperplasia can be divided into:
Hormonal hyperplasia, which increases the
functional capacity of a tissue when needed,
and uterus pregnancy
2) Compensatory hyperplasia, which increases
tissue mass after damage or partial resection liver transplantation
This form of pathologic
hyperplasia is a common
cause of abnormal
menstrual bleeding.
Endometrial hyperplasia
Patients with hyperplasia of the endometrium are at
are abnormal, the process remains controlled and
increased risk for developing
endometrial cancer
Hyperplasia is the result of
growth factor–
driven proliferation of mature cells and, in
some cases, by increased output of new cells
from tissue stem cells
In atrophy The degradation of cellular proteins occurs
mainly by the
ubiquitin-proteasome pathway
Atrophy is also accompanied by increased
autophagy autophagy vacuoles (lipofuscin
granules)
Brown atrophy
Metaplasia
reversible change in which one
differentiated cell type (epithelial or mesenchymal) is
replaced by another cell type
The most common epithelial metaplasia
columnar to
squamous epithelium=squamous metaplasia
intestinal metaplasia
squamous to columnar type may also
occur=
Formation of cartilage, bone, or adipose tissue
(mesenchymal tissues) in tissues that normally do not
contain these elements
Connective tissue metaplasia
Squamous metaplasia occurs in
respiratory tract in response to chronic irritation, deficiency
of vitamin A (retinoic acid), habitual cigarette
smoker
In Barrett esophagus
the esophageal squamous
epithelium is replaced by intestinal-like columnar
cells under the influence of refluxed gastric acid
bone formation in muscle
Myositis ossificans
Metalaşma hangi hücrelerde olur
Stem cell
Undifferentiated mesenchymal cells
The hallmarks of reversible injury
Reduced oxidative phosphorylation
Cellularr swelling
Reversible injury is characterized by
generalized swelling of the cell and
its organelles
• blebbing of the plasma membrane
•detachment of ribosomes from the
ER
•clumping of nuclear chromatin
