LEC3 - CELLULAR ADAPTATION Flashcards
are reversible changes in the number,
size, phenotype, metabolic activity or functions of cells in response to changes in their environment.
Adaptations
Adaptations are reversible changes in the _______ of
cells in response to changes in their environment.
number,
size,
phenotype,
metabolic activity or functions
2 types of adaptations
◆ Physiologic adaptations
◆ Pathologic adaptations
An adaptation to stress can progress
to functionally significant __
if the stress is not relieved
cell injury
Represent responses of cells to normal stimulation by hormones or endogenous chemical mediators.
Physiologic Adaptations
a physiologic adaptation that induced enlargement of the breast and uterus during pregnancy, this is mainly because of ___
Hormone
Responses to stress that allow cells to modulate their structure and function.
Pathologic Adaptations
is an increase in the size of cells
resulting in increase in the size of the organ
Hypertrophy
form of adaptation wherein there’s increased cell and organ size
Hypertrophy
Hypertrophy
induced by growth factors produced in response to ___ or ___
mechanical stress or other stimuli
what are the causes of increase of the size of the cell or known as hypertrophy
PHYSIOLOGIC CELLULAR HYPERTROPHY
PATHOLOGIC CELLULAR HYPERTROPHY
the type of hypertrophy which is one of the example is
the Increased workload in the striated muscle cells in both skeletal and heart
Physiologic Cellular Hypertrophy
the type of hypertrophy which is one of the example is
Cardiac enlargement that occurs with hypertension or aortic valve disease
Pathologic Cellular Hypertrophy
a lot of number of genes that will stimulate the number of growth factors
transduction pathway
the causes of the increase in number of cells in Physiologic Cellular Hypertrophy
induced by growth factors that stimulates cell protein
Hypertrophy can be physiologic or pathologic and is
caused either by ____or ____
increased functional demand or by growth factor or hormonal stimulation
what is the common pathologic cellular hypertrophy __
cardiac enlargement
what are the mechanical stressors causing cardiac enlargement
hypertension
The type of reversible injury is
ischemia
the type of irreversible injury is ___.
ischemic coagulative necrosis
the normal ventricular wall’s thickness is ___ cm
1-1.5
to confirm myocardial hypertrophy, we will use an enzyme substrate that colors viable myocardium.
Triphenyltetrazolium chloride
Triphenyltetrazolium chloride will color the myocardium as colored ____ signifying viable cells
magenta
using Triphenyltetrazolium chloride enzyme substrate, how will you know if the cells are already dead
Failure to stain is due to enzyme loss after cell
death.
➔ Increased cell numbers in response to hormones
and other growth factors
HYPERPLASIA
2 causes of HYPERPLASIA
hormones
growth factors
occurs in tissues whose
cells are able to divide or contain abundant tissue
STEM CELLS
HYPERPLASIA
TWO TYPES OF PHYSIOLOGIC HYPERPLA
HORMONAL HYPERPLASIA
COMPENSATORY HYPERPLASIA
exemplified by the proliferation of the
glandular epithelium of the female breast at puberty and during pregnancy
HORMONAL HYPERPLASIA
residual tissue grows after removal
or loss of part of an organ.
COMPENSATORY HYPERPLASIA
COMPENSATORY HYPERPLASIA is usually happens in what organ
liver
weight of liver
1200-1500 grams. 2% of the body mass
a type of hyperplasia that has Excessive hormonal or growth factor
stimulation
PATHOLOGIC HYPERPLASIA
example of PATHOLOGIC HYPERPLASIA
● Endometrial hyperplasia - causes bleeding
● Benign prostatic hyperplasia - thickening
● Papillomaviruses - growth factor causing warth
Shrinkage in the size of the cell by the loss of cell substance
ATROPHY
ATROPHY
Decreased cell and organ size as a result of ___ and ___
decreased nutrient supply or disuse
Associated with decreased synthesis and
increased proteolytic breakdown of cellular
organelles.
ATROPHY
CAUSES OF ATROPHY
➔ Decreased Workload
➔ Loss of Innervation,
➔ Diminished Blood Supply,
➔ Inadequate Nutrition,
➔ Loss of Endocrine Stimulation,
➔ Aging (Senile Atrophy)
MECHANISMS OF ATROPHY
combination of decreased protein synthesis and increased protein degradation in cells.
in the increase degradation of the cell during the atrophy.
The degradation of cellular proteins occurs mainly by the _____
ubiquitin-proteasome
pathway.
a fragmentation of the protein in the cytosol
ubiquitin-proteasome pathway.
why do decreasing of protein syntheis and increase of protein degradation happens in atrophy?
◦ Protein synthesis decreases because of reduced metabolic activity.
◦ The degradation of cellular proteins occurs mainly by the ubiquitin-proteasome pathway.
◦ increased autophagy
is a reversible change in which one
adult cell type (epithelial or mesenchymal) is
replaced by another adult cell type.
METAPLASIA
response to chronic irritation that makes cells better able to withstand the stress
METAPLASIA
usually induced by altered differentiation pathway
of tissue stem cells
METAPLASIA
METAPLASIA may result to
reduce functions
increase propensity for malignant transformation
2 types of METAPLASIA
EPITHELIAL METAPLASIA and MESENCHYMAL METAPLASIA
occurs in epithelium exposed to mechanical
trauma or chronic irritation of prolonged
inflammation
EPITHELIAL METAPLASIA
EPITHELIAL METAPLASIA causes
mechanical trauma
chronic irritation of prolonged inflammation
prolonged vitamin A deficiency
EPITHELIAL METAPLASIA
prolonged vitamin A deficiency
most commonly leading to replacement of
columnar cells by ___
stratified squamous
epithelium
the epithelial metaplasia that occurs upon the lack of vitamin A causing the replacement of columnar cells by stratified squamous epithelium are usually seen in what part of the body
respiratory passages,
linings of gland ducts
mucosal lining of endocervix
what are being replaced in mesenchymal metaplasia?
fibroblast
occurring in connective tissues whereby fibroblasts
are transformed into more highly differentiated
forms
MESENCHYMAL METAPLASI
MESENCHYMAL METAPLASIA
➔ occurring in connective tissues whereby fibroblasts
are transformed into more highly differentiated
forms such as __
osteoblasts,
fat cells
tissue macrophages
according to the table
hypertrophy is an increased in cell and organ size which often a response to _____
increase workload,
induced by growth factors in response to mechanical stress or other stimuli
according to the table, hyperplasia results in response to
growth factors and hormones
The intracellular accumulations may be located in
-Cytoplasm
-Within organelles (typically lysosomes) -In the nucleus,
-May be synthesized by the affected cells or may be produced elsewhere.