Cell Pathology Flashcards
Define atrophy
- Shrinkage in the size of a cell and consequently the size of a whole organ, by the loss of cell substance
- We see a decrease in weight of an atrophic organ
Define hypertrophy
- Increase in the size of a cell and consequently the size of a whole organ
- Physiological or pathological
- important because muscle cells (skeletal and cardiac) cannot divide so an increase in cell size is the only way in which an organ can get bigger
Define hyperplasia
- Increase in the number of cells in an organ
- Physiological or pathological
Define metaplasia
- Reversible change in which one normal adult cell type (mature cell) is replaced by another (normal adult cell replacement)
- Physiological or pathological
Define dysplasia
- Precancerous cells which show the genetic and cytological features of malignancy but do not invade the underlying tissue (does not invade through the basal lamina)
- bridge between normality and cancer
Examples of atrophy
- Gastric atrophy causing pernicious anaemia (anaemia resulting from vitamin B12 deficiency)
- Posterior cortical atrophy from the loss of neurones in Alzheimer’s disease
Examples of hypertrophy
Physiological: muscle hypertrophy in the uterus during pregnancy
Pathological: left ventricular hypertrophy in response to hypertension
Examples of hyperplasia
Physiological: oestrogen-induced endometrial hyperplasia
Pathological: benign prostatic hyperplasia, carcinoma
Examples of metaplasia
Physiological: metaplasia in the cervix
Pathological: Barrett’s Oesophagus (columnar lined oesophagus)
Examples of dysplasia
- Cervical intraepithelial neoplasia
- Patients with Barrett’s oesophagus are associated with a much greater oesophageal cancer risk because metaplasia is typically followed by dysplasia
Light microscopic changes associated with reversible cell injury
- fatty changes (fat accumulation in cells=fatty globules)
- cellular swelling (ballooning)
Light microscopic changes associated with irreversible cell injury
-The different types of necrosis
Define coagulative necrosis
- substance changes but the shape of the molecule does not change
- tissue retains structure after coagulation and can be recognised (nuclei gone and inflammatory cells present)
- myocardial infarction example
Define liquefactive necrosis
- tissue broken down leaving empty space which fills with fluid (tissue is totally liquefied)
- identification only from cells surrounding it (empty space)
- old cerebral brain infarct example
Define caseous necrosis
-form of granulomatous inflammation
-characteristic ‘cheesy’ appearance where
necrotic area becomes granular
-tissue cannot be recognised from structure
-associated with pulmonary tuberculosis
Define fat necrosis
- breakdown of fat cells by lipase release or trauma (significantly severe fat trauma)
- release of lipases digests the fat and hydrolyses the triglycerides into free fatty acids and glycerol
- free fatty acids combine with calcium in ECF forming calcium fat salts which deposit themselves
- associated with acute pancreatitis
Define necrosis
Confluent cell death associated with inflammation
Define apoptosis
Programmed cell death of single cells, not associated with inflammation
-normal in organism’s growth and development
Features of apoptosis
- active (energy dependent=requires ATP hydrolysis)
- physiological and pathological
- not associated with inflammation (no bystander damage to healthy tissue)
Features of necrosis
- cellular reaction of inflammation
- not just single cells (areas)
- not energy dependent
- always pathological
Define necroptosis
Programmed cell death associated with inflammation
Features of necroptosis
- energy dependent
- halfway between apoptosis and necrosis
- many causes including viral infection
- generally occurs in pathological circumstances
Causes of cell injury
G=genetic defects
I=infectious agents (bacteria, viruses, multicellular parasites)
N=nutritional imbalances
C=chemical agents (includes iatrogenic injury resulting from the drugs/medication doctors give)
H=hypoxia
A=aging
P=physical agents (eg: gunshot wound, trauma etc)
I=immunological reactions (autoimmune disease where the body attacks itself=conditions include rheumatoid arthritis)
What causes cell adaptation?
- stress on cells of increased demand/load
- cell remains in equilibrium but works in newly adapted state
What causes cell injury?
- respond to injurious stimuli (stress which is harmful)
- stress exceeds the cell’s adaptive capability
Define lethal cell injury
Produces cell death
Define sublethal cell injury
Injury does not amount to cell death(injury does not kill the cell/organism)
Define reversible cell injury
Within certain limits, the cell can return back to normal
Define irreversible cell injury
Progresses to cell death
Intracellular mechanisms/systems vulnerable to cell injury (linked systems so damage to one will impact the others)
- cell membrane integrity
- ATP generation
- protein synthesis
- integrity of the genetic apparatus
List the 5 adaptive responses of cells
- Atrophy (growth)
- Hypertrophy (growth)
- Hyperplasia (development)
- Metaplasia (development)
- Dysplasia (development)
Define degenerative
Change to a tissue to a lower or less functionally active form
Define ulcer
Local defect or excavation of the surface of an organ or tissue, produced by the sloughing of necrotic inflammatory tissues
Explain Barrett’s Oesophagus
Normal epithelial tissue lining of the oesophagus converts from stratified squamous to columnar (resembles the lining of the small intestine)
- Cause: acid reflux
- Reversal: PPI’s to inhibit acid production (Proton Pump Inhibitors)
Explain metaplasia in the cervix
-Endocervix is lined with columnar epithelium
-Ectocervix is lined with stratified squamous epithelium
-Columnar of endocervix is converted to stratified squamous
Cause:At puberty/during pregnancy, the cervix expands and fragile columnar epithelial lining of the endocervical canal is exposed to harsher more acidic environments in the vagina
Reversal: cervix contracts and closes up
Factors affecting the cellular response to injurious stimuli
- type of injury
- duration of the injury
- severity of the injury
Factors affecting the consequences of an injurious stimuli
- type of cell (some cell types are naturally more resistant to injury than others=example of bone, fat, brain and heart to oxygen deprivation)
- Cell status (more vulnerable to various agents if dividing)
- adaptability of the cell
- genetic makeup of the cell
Define infarction
Tissue death due to ischaemia
Causes of cell death
- Stress is too severe
- Prolonged/persistent stress
Physiological effects
-result of a normal stressor (healthy people)
Pathological effects
-result of an abnormal stressor (diseased state)
Hypertrophy causes
- Increased functional demand
- Specific hormonal stimulation (seen in pregnancy)
Physiological hyperplasia causes
- Hormonal(eg: Oestrogen causes wave of proliferation of the endometrium=inner lining of the uterus)
- Compensatory (tissue previously lost)
Pathological hyperplasia causes
- excessive hormonal or growth factor stimulation
- observed in cancer (high cell proliferation)
Necrosis mechanism
- enzymatic digestion
- leakage of cellular contents
- dead cells attract inflammatory cells
Apoptosis mechanism
- cell implodes on itself (nucleus shrinks and parts of cell break off but cell membrane is never ruptured=no inflammation)
- Phagocytosis by macrophages on apoptotic cells and fragments
Cases reported to the Coroner in England and Wales
- Cause of death is unknown
- Deceased has not been seen by a certified doctor either after death or 14 hours before death
- Unnatural, violent or suspicious death (homicide)
- Due to an accident regardless of when this occurred
- Due to neglect by self or others (subjective and difficult to define)
- Due to industrial disease or deceased person’s employment (occupational such as mesothelioma linked to asbestos exposure)
- Abortion impact on mother
- During an operation or before recovery from the effects of anaesthetic
- suicide
- poisoning
- Occurred during or shortly after detention in police or prison custody (exception of DoLS=patients lack the capacity to consent to their care and treatment)
Purpose of Coroner’s autopsy
- Conducted to establish the cause of death
- Remit over once Coroner determines the cause of death
Define coroner
- independent judicial officer of the crown (employed by the queen) who has statutory duty to investigate the circumstance of certain categories of death for the protection of the public
- investigates death and how it occurred
- reported by most junior doctor of the firm
- only in court room with jury if patient died in police custody etc
Consent for Hospital autopsy
- obtained from next of kin/relatives
- any material taken from body with relevant consent
Consent for Coroner’s autopsy
- None=investigating cause of death
- family wishes must be considered
- material only taken if it is needed to find the cause of death
Purpose of Hospital’s autopsy
- Allows very thorough examination of the deceased, extent of disease, treatment and its effects
- Performed in the case of an audit where there is major discrepancy between stated and actual cause of death
- medical teaching purposes
- monitor the effectiveness of new treatments
- medical research (eg: knowledge of variant CJD relies on the study of the post mortem brain tissue)
Multiple secondary effects rapidly occur from cell injury to vulnerable systems
-structural and biochemical components of a cell are so integrally related
Loss of cellular function occurs before?
- cell death and then morphological changes (structure, shape or form)
- often loss of function kills a patient before the morphological changes take place=no observations on post mortem
Define bruise (contusion)
-extravasated collection of blood which has leaked from damaged small arteries, venules and veins but not capillaries
Define abrasion (graze or scratch)
- most superficial of the blunt trauma injuries
- confined to the epidermis
Define laceration
-split to the skin as a result of blunt force trauma which overstretches the skin
Define cut (slash)
-split in the skin where the injury length is longer than its depth
Define stab (penetrating injury)
-split in the skin where injury depth is greater than the width
Define incised wounds
- Term discrepancy
- some means cuts and stabs, others say it means the same as cuts
Define cancer
- malignant neoplasm
- abnormal growth of cells which tend to proliferate in an uncontrolled way and in some cases, to metastasise
Define neoplasm
- abnormal mass of tissue, whose growth is autonomous (independent) of the body’s normal homeostatic growth-regulating mechanism and escapes the normal constraints on cell proliferation
- the growth is purposeless, uncoordinated and will continue after the stimulus which initiated the change is removed
Define tumour
- any kind of MASS forming lesion
- any swelling in or on a part of the body
- may be neoplastic (benign or malignant), hamartomatous or inflammatory
- example of a non-neoplastic tumour is nasal polyps (chronic inflammatory cause)
Define metastasis
Spread of a malignant tumour from its site of origin
Define carcinogen
Any substance that, when exposed to living tissue, may cause the production of cancer
Define malignant
- neoplasm classification
- invades local tissues and has the potential to spread to distant sites of the body
- difficult to remove due to invasion and metastasis=local surgery plus focus on chemotherapy and radiotherapy
Define benign
- neoplasm classification
- remains localised=defined and well demarcated
- easy to remove by local surgery
Features to distinguish between benign tumours and malignant tumours
- invasion
- metastasis
- differentiation
- growth pattern
Examples of environmental carcinogens and the cancers they cause
- UV radiation=basal cell carcinoma, squamous cell carcinoma and multiple myeloma
- ionising electromagnetic radiations (eg: X rays, X ray used in CT scans)=leukaemia and solid tumours
- asbestos exposure=mesothelioma
Aim of cancer screening programmes
Detect cancer at the pre-invasive (dysplastic) or early stage
Principles of cancer screening programmes
- condition is an important health problem
- treatment is possible after screening
- facilities for diagnosis/treatment are available
- recognisable latent (dormant) or early symptomatic stage
- suitable test or examination
- test is acceptable to the population
- natural history is understood
- agreed policy on which patients to treat
- cost-effective
- case finding should be a continued process in the population
Routes which tumours spread
- direct extension
- haematogenous
- lymphatic
- transcoelomic
- perineural
Examples of chemical carcinogens and the cancers they cause
- hydrocarbons
- amines
- nitrosamines
- azo dyes
- alkylating agents
Examples of infectious carcinogens and the cancers they cause
- Epstein-Barr virus (oncogenic virus)=Burkitt’s lymphoma
- HPV (oncogenic virus)=cervical cancer
- Hepatitis B virus (oncogenic virus)=hepatocellular carcinoma
- HHV-8 (oncogenic virus)=Kaposi’s sarcoma
- Helicobacter pylori (bacterial carcinogen)=gastric carcinoma and lymphoma
Explain invasion
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Explain metastasis
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Explain differentiation
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Explain growth pattern
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Define hamartomas
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Define heterotopias
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Primary description of a neoplasm
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Secondary description of a neoplasm
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Define tetratomas
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Suffix ‘oma’ means?
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Malignant tumours with the suffix ‘oma’
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Features of tumour cells
- high nuclear-cytoplasmic ratio compared to normal cells
- more mitoses
- mitoses present may be abnormal
- marked nuclear pleomorphism
Link between benign and malignant neoplasms
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Define direct extension
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Define haematogenous
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Define lymphatic
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Define transcoelomic
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Define perineural
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Assessing tumour spread
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TNM staging system
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Most important factor determining tumour prognosis
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Define grade
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Define stage
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Define shock
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Define thrombosis
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Define embolism
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Define infarction
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Causes of thromobosis
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Causes of embolism
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Causes of infarction
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Consequences of thrombosis
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Consequences of embolism
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Consequences of infarction
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3 main causes of death in young people
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