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Tissue Response To injury, image, Tee Shiau Zuan (012021070817) - Coggle…
Tissue Response To injury
Concept
Definition of cell injury
Cell injury, also known as cell damage, is a variety of changes of stress that a
cell suffers
structure changes
(lesions)
and biochemical changes
(functions)
due to external as well as internal environmental changes
How does tissue response to injury
Cellular responses can be categorized as:
Adaption
Degeneration
Necrosis
How to know what type of cellular response the cell is suffering?
Type of cell & tissue involved
Cell type
Genetically make up
Adaptibility
Status
Nature of the injury
Type of etiology effector
Duration
Severity
What is tissue?
Tissue is the formation of a few cells. All cells have the same basic structure and consist of three parts which are the cell membrane, the cytoplasm, and the nucleus.
Cell membranes
and
organelles
are
targets
for injury by various factors such as toxic diseases, microbes, and genetic metabolic.
Etiology
Acquired causes
Acquired causes refer to factors that are acquired or external to the cell
Physical Agents
Chemical Agents
Infectious Agents
Nutritional Imbalances
Hypoxia
Genetic causes
Genetic causes involve intrinsic factors related to the cell's genetic makeup.
Genetic Mutations
Inherited Metabolic Disorders
Chromosomal Abnormalities
Epigenetic Alterations
Types of cell injury
Reversible cell injury
Definition
Reversible cell injury, also known as RCI, is a cellular injury with the hallmark of morphological changes to the cell. These changes can be reversed if the injurious stimulus is removed.
Characteristics of reversible cell injury
-
Swelling
of the cell
ESPECIALLY MITOCHONDRIA
Blebbing
of the plasma membrane
Detachment
of ribosome from endoplasmic reticulum
Clumping
of nuclear chromatin
The characteristics listed associated with decreased generation of ATP, loss of cell membrane integrity, defects protein synthesis, cytoskeletal damage, and DNA damge.
Example of reversible cell injury
Renal tubular cell injury ---> certain metabolic alterations and structural changes can lead to reversible injury
Gastric epithelial cell injury ---> non-steroidal anti-inflammatory drugs can cause injury to gastric epithelial cells
Kidney glomerular injury ---> recruitment of cellular processes that can repair the damage
Irreversible cell injury
Characteristics of irreversible cell injury
Increased cell swelling
--> due to disruption of lysosomes
-
Severe mitochondrial damage
that formed of amorphous densities
Membrane disruption
in the cytocavitary network.
Severe
nuclear change
Pyknosis
Karyorrhexis
Karyolysis
Definition
Irreversible cell injury refers to a state of cellular damage beyond the point of recovery or repair. It occurs when cells experience severe and prolonged stress or insult, leading to the disruption of essential cellular functions and ultimately resulting in cell death.
Example of irreversible cell injury
Renal tubular cell injury
---> H2O2 induces a significant rise in intracellular free calcium
Retinal ganglion cell injury
---> neurodegenerative diseases in the mammalian central nervous system often lead to irreversible neuronal loss
Spinal cord injury
---> cause irreversible impairment or loss of motor, autonomic, and sensory functions
Pathogenesis
Reversible Cell Injury
Cellular Stress/Insult
↓
Impaired ATP Production result in energy Depletion
↓
Cellular Swelling due to water Influx
↓
Detachment of Ribosomes
↓
Impaired Protein Synthesis
↓
Impaired Ion Pumps result in ionic Imbalance
↓
Loss of Plasma Membrane Integrity result in leakage of Intracellular Contents
↓
Reversible Cell Injury
Recovery/Cellular Adaptation
Fate of reversible cell injury
Reversible cell injury can have different outcomes. If the stressor is removed promptly and the injury is mild, cells can fully recover. They can also adapt to the ongoing stress or undergo programmed cell death (apoptosis) as a protective mechanism.
Irreversible Cell Injury
Cellular stress/Insult
↓
Impaired ATP production result in energy depletion
↓
Cellular swelling result in water influx
↓
Detachment of ribosomes
↓
Impaired protein synthesis
↓
Impaired ion pumps result in ionic Imbalance
↓
Loss of plasma membrane integrity result in leakage of intracellular contents
↓
Mitochondrial dysfunction result in reactive oxygen species (ROS) production
↓
DNA, protein, lipid damage
↓
Irreversible membrane Damage
Cell Death (Necrosis or Apoptosis)
Fate of irreversible cell injury
Irreversible cell injury leads to permanent damage and necrosis. The cells are unable to recover or repair themselves. This can result in tissue dysfunction and may contribute to organ failure.
Tee Shiau Zuan (012021070817)
