cell death Flashcards
what causes cell stress and injury
Oxygen deprivation (hypoxia)
Chemical agents
Infectious agents Immunological reactions
Genetic Defects
Protein deficiencies, eg. damaged DNA
name three of the categories in which cell injury and stress are grouped
nutritional imbalances
physical agents
aging
describe cell adaptation
reversible changes to cells in response to environmental changes
types of cellular adaptations
physiological adaptations
pathological adaptations
physiological adaptation
Response to normal stimulation, example, hormones and chemical mediators
pathological adaptations
Response to stress, example, modulate structure and function to escape injury
what are the most common pathological adaptations
Hypertrophy (increase in cell size)
Hyperplasia (increase in cell number)
Atrophy (decrease in cell size)
Metaplasia (change in cell type)
briefly describe hypertrophy
increase in cell size due to increased amounts of structural proteins and organelles in the cell. this could also lead to increase in organ size
are there any new cells formed during hypertrophy
no
when does hypertrophy occur
when non dividing cells are exposed to stress
examples of non-dividing cells
neurons
cardiomyocytes
skeletal muscle cells
red blood cells
mature osteocytes
causes of hypertrophy
Caused by increased functional demand
specific hormonal stimulation
hyperplasia
increase the number of cells
in which cells can hyperplasia take place
cells that can replicate
can hyperplasia occur alongside hypertrophy
yes
under which types of adaptation does hyperplasia fall
physiological and pathological
examples of physiological hyperplasia
hormonal and compensatory hyperplasia
examples of pathological hyperplasia
Excessive hormone or growth factor stimulation e.g.HPV causes skin warts
dysplasia
a term used in medicine to describe the abnormal development, growth, or organization of cells within a tissue or an organ.
how can hyperplasia lead to dysplasia
if the cells that undergo hyperplasia become irreversible, then that can lead to dysplasia
what chronic condition could dysplasia cause
cancer
Atrophy
Decrease in size of cells (shrink) by loss of cell substance. this could lead to decrease in size of organ
what does atrophy in cells lead to
reduced protein synthesis and increased degradation
do cells die during atrophy
no
literal meaning of autophagy
“Self eating”
conditions that atrophy could lead to
aging and reduced blood supply
decreased workload, for example, immobilisation of the limbs in fracture cast
metaplasia
a process in which one mature or fully differentiated cell type within a specific tissue or organ is replaced by another mature cell type
what is metaplasia believed to be a result of
change in gene expression
what can metaplasia lead to
reduced function or increased chance of malignant transformation
what are the two types of cell death
apoptosis
necrosis
necrosis
a form of cell death that occurs as a result of premature and uncontrolled cell damage, typically due to external factors or harmful influences
apoptosis
a highly regulated and programmed process of cell death that plays a fundamental role in maintaining the health and homeostasis of multicellular organisms.
is necrosis a physiological process
no, it is always a pathological process
morphological alterations that could lead to irreversible cell injury(necrosis)
Nuclear shrinkage, fragmentation and dissolution
Breakdown of plasma and organelle membranes
Leakage and enzymatic digestion of cellular contents
what type of cell death is also termed as cell suicide
apoptosis
physiological conditions that could induce apoptosis
Cellular stress response
Cellular aging
Immune system regulation
Tissue remodelling
Embryonic development
pathological conditions that could induce apoptosis
Cellular stress
Cancer treatment
DNA damage
Autoimmune disorders
Neurodegenerative disease
