Cell Pathology Flashcards
Define atrophy
A shrinkage in the SIZE of the cell, or organ by loss of cell substance
Define hypertrophy
An increase in the SIZE of the cell, or organ. This can be physiological or pathological.
Define hyperplasia
An increase in the number of cells
Define metaplasia
A reversible change where one adult cell type is replaced by another
Define dysplasia
This can refer to an abnormal organisation of cells in tissue, or a pre-cancerous stage.
What are the hallmarks of a reversible injury as seen under a light microscope?
Fatty change
Cellular swelling
Define necrosis:
Confluent cell death associated with inflammation.
What are the four types of necrosis:
- Coagulative necrosis (cells die but still recognisable as cells as they maintain cellular architecture)
- Liquefactive necrosis (cells die and become liquid)
- Caseous necrosis (look cheesy; become granules and unrecognisable as cells)
- Fat necrosis (enzymes become free causing Ca2+ to be released and fat to be deposited)
What is an ulcer?
An ulcer is a local defect, or excavation of the surface produced by the sloughing of necrotic inflammatory tissue.
What is apoptosis?
Apoptosis is programmed cell death that is not associated with inflammation.
Under whose authority does the coroner operate?
The Crown
Does the coroner’s autopsy need consent?
No
When does the doctor need to report a death to the coroner?
When the cause death is unnatural, or unknown. Or shortly after police custody.
What are hospital autopsies used for?
- Audit
- See if new treatments work
- Teaching
- Research
What are death certificates useful for?
Epidemiology
What is a bruise?
A bruise or contusion is a blunt trauma injury where blood has leaked from damaged small arteries, venues and veins.
What is an abrasion?
A blunt trauma injury which is a graze or scratch.
What is a laceration?
A split to the skin caused by a blunt force which overstretches the skin.
What is the difference between a cut and a stab?
They are both sharp trauma injuries. A cut is where the length is longer than the depth. A stab is where the depth is greater than the width.
What is acute inflammation?
A transient early response to injury caused by the release of chemical mediators
What is chronic inflammation?
Inflammation of prolonged duration, usually caused by persistence of injury causing agent
What are the components of an inflammatory reaction?
- Cells (neutrophils, macrophages, lymphocytes, esosinophils, mast cells)
- ECM (collagen, proteoglycans, fibroblasts)
- Soluble Factors (antibodies, complement, cytokines, coagulation system)
- Vessels
What are the cardinal signs of inflammation?
- Calor
- Rubor
- Dolor
- Tumor
- Loss of function
How can mast cells cause acute inflammation?
Mast cell plasma membrane IgE interaction with antigen leads to degranulation of histamine. This causes vasodilation and increased vascular permeability,
What medications reduce inflammation?
Antihistamines reduce histamine levels
Aspirin reduce prostaglandin levels
Special antibodies can target IL-1 and TNF
What is the difference between exudate and transudate?
Transudate is produced when hydrostatic pressure is greater than colloid osmotic pressure. Exudate is produced by leaky vessels.
How is acute inflammation valuable?
Exudate dilutes pathogen and allows soluble mediators to spread.
How is acute inflammation eventually stopped?
- Mediators and neutrophils have a short half-life
- Macrophages release anti-inflammatory products
- Stimulus is removed
- Mast cells and lymphocytes release anti-inflammatory products
Give examples for causes of chronic inflammation
- Persistant infection
- Prolonged exposure to toxic agent
- Autoimmunity
- Foreign body
What cells have more of a role in chronic inflammation?
Macrophages, lymphocytes and plasma cells
What role does a macrophage play in inflammation?
Classically activated macrophages cause pathogenic inflammation, and have microbicidal actions.
Alternatively activated macrophages have anti-inflammatory effects and have a role in wound repair as well as fibrosis.
What is a granuloma?
A cluster of macrophages surrounded by T cells.
What can cause a granuloma?
Infection
Foreign material
Reaction to tumours
Immune diseae
What are the local and systemic sequelae inflammation?
Locally: - excessive tissue damage - secondary effects on nearby tissue Systemic: - evolve into systemic inflammatory reaction causing multi-organ failure.
Compare resolution and repair
Resolution is where tissue architecture returns to normal. Only occurs if cells are able to regenerate and little structural damage was done.
Repair is where normal tissue is replaced with fibrous scar tissue. The scar undergoes remodelling which is the reorientation of collagen fibres for maximal tensile strength.