cell fate and injury Flashcards
- List the causes of cell injury
Infectious agents
Genetic defects
O2 deprivation
Physical agents Aging Nutritional imbalance Immunological reactions Chemical agents
I GO PANIC
- What is ischaemia?
- What is an infarction?
Condition in which blood flow is restricted or reduced in a part of the body
Cell death due to do ischaemia
- What does a cellular response to injury depend on?
Type of injury
Duration Severity Type of cell Status
what four intracellular systems are particularly vulnerable
Cell membrane integrity
ATP generation
Protein synthesis
Integrity of genetic apparatus
What does lethal mean?
What does sub lethal mean?
Causes cell death
Produces injury but not cell death
may be reversible or progress to cell death
- What is hypertrophy
- What is it caused by?
- Give a physiological and pathological example
Process by which cells become larger and consequently an increase in size of organ.
Caused by increased functional demand or specific hormone stimulation
physiological - uterus during pregnancy pathological - hypertension and valve disorder
- What is meant by Atrophy and give an example?
Shrinkage in size of cell or organ due to loss of components
e.g. muscle shrinkage- physiological
brain of dementia patient- pathological
- What is Hyperplasia and what is the difference between physiological and pathological hyperplasia?
Increase in the number of cells in an organ
Physiological hyperplasia can be hormonal or compensatory Pathological hyperplasia due to excessive hormonal or growth factor stimulation
- What is meant by Metaplasia?
- Give an example of physiological metaplasia
- Give an example of pathological metaplasia
Reversible change in which one adult cell type is replaced by another
External surface of the cervix is lined by squamous epithelium, internal canal lined by columnar epithelium. Cervical expansion results in exposure of columnar epithelium Combination of factors (vaginal pH) stimulate metaplasia of columnar cells into squamous epithelium, reversible change Barett’s oesophagus - squamous lined epithelium cells exchanged into columnar epithelium. Acid reflux induces metaplasia
- Define Dysplasia
- How can one identify Dysplasia cells?
Intermediate step between normal tissue and cancer
Precancerous cells which show genetic and cytological features of malignancy but not invading the underlying tissue
High nuclear : cytoplasmic ratio More mitosis
- What is necrosis?
- What are the 4 different types of necrosis?
Confluent cell death associated with inflammation
Coagulative Necrosis - Architecture of dead cells is maintained (solid) eg myocardial infarction
Liquefactive Necrosis - Liquified cell death eg cerebral infarction Caseous Necrosis - Tissue maintains cheese-like appearance eg pulmonary TB Fat Necrosis - Death of fat cells, occurs at fatty tissues where fat is replaces by oily contents of cell eg acute pancreatitis
- What is the difference between apoptosis and necrosis?
Apoptosis may be physiological
Apoptosis is an active energy dependent process Apoptosis is death of cells when there is no inflammation around them whereas necrosis does have inflammation around dead cells The cell membrane of cells undergoing apoptosis remains intact
- What is apoptosis?
- What are the causes of apoptosis?
Programmed cell death of individual cells
Embryogenesis
Deletion of auto-reactive T cells in the thymus Hormone-dependent physiological involution Cell deletion in proliferating populations A variety of mild injurious stimuli that cause irreparable DNA damage that in turn, triggers cell suicide pathways
- What is necroptosis?
- Causes?
Programmed cell death associated with inflammation
eg viral infection
