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− | # | + | ==An Introduction to General Pathology== |
+ | |||
+ | * The term '''pathology''' is derived from: | ||
+ | ** '''Pathos''', or suffering | ||
+ | ** '''Logos''', or reasoning/logic. | ||
+ | * Pathology is defined as the study of disease including: | ||
+ | ** '''Aetiology''' - causal factor(s) | ||
+ | ** '''Pathogenesis''' - the development of the disease within the body. | ||
+ | ** '''Lesions''' - the observable structural changes in the tissues and fluids of the body. | ||
+ | ** '''Pathophysiology''' - the functional changes in diseased tissues. | ||
+ | ** '''Sequel''' - the consequences of the disease in the body. | ||
+ | ** '''Remote effects''' - the effect of disease in one tissue on other tissues in the body. | ||
+ | |||
+ | ===Lesions=== | ||
+ | |||
+ | * Lesions are the abnormalities or changes seen in living tissues due to disease. | ||
+ | * Observed in | ||
+ | ** The live animal | ||
+ | ** Tissues surgically removed from the live animal | ||
+ | *** Biopsy/ excision | ||
+ | ** Animals soon after death | ||
+ | *** Necropsy, post-mortem examination. | ||
+ | |||
+ | ====Decription of Lesions==== | ||
+ | |||
+ | * Descriptions of lesions is very important | ||
+ | * Whole organs, tissues or individual lesions are described under headings such as | ||
+ | *# Size | ||
+ | *# Shape | ||
+ | *# Colour | ||
+ | *# Weight | ||
+ | *#* Generally in relation to body weight | ||
+ | *# Texture and Consistency | ||
+ | *# Appearance of the cut surface | ||
+ | *# Contents of hollow organs | ||
+ | *# Position, relationships and effects on adjacent tissues | ||
+ | |||
+ | *'''See [[General Pathology - Recognition and Description of Lesions|Recognition and Description of Lesions]]''' | ||
+ | |||
+ | ===Disease=== | ||
+ | |||
+ | ====Definition and Type==== | ||
+ | |||
+ | * '''Disease''' is a definite morbid (illness producing) process, having a characteristic train of symptoms or signs. | ||
+ | ** May affect the whole body or any of its parts. | ||
+ | ** The disease's aetiology, pathology and prognosis may be known or unknown. | ||
+ | * There are two main categories of disease. | ||
+ | *# '''Acute''' | ||
+ | *#* Characterised by sudden onset and short duration. | ||
+ | *#* The outcome of acute disease may be: | ||
+ | *#** Death | ||
+ | *#** Resolution due to host defence response or clinical therapy | ||
+ | *#** Progression to chronic disease | ||
+ | *# '''Chronic''' | ||
+ | *#* Characterised by insidious onset and protracted course. | ||
+ | *#* The outcome of chronic disease may be: | ||
+ | *#** Progressive destruction of tissue | ||
+ | *#*** Compromises funtion and endangers life, | ||
+ | *#** The halting of the course of disease, with tissue repair by scarring. | ||
+ | |||
+ | ====Factors Involved in the Development of Disease==== | ||
+ | |||
+ | * There are three factors which conspire with each other to produce disease. | ||
+ | *# '''The individual animal'''. | ||
+ | *#* In particular, the animal's nutritional and immune status | ||
+ | *#** This is modified by: | ||
+ | *#*** Recent or concurrent disease | ||
+ | *#*** Previous exposure to the agent(s) responsible | ||
+ | *# '''The disease-causing agent(s)'''. | ||
+ | *#* Most do not cause a uniform pattern of disease | ||
+ | *#** Host defences are important in determining the presentation of the disease. | ||
+ | *#* An agent's capacity to produce disease depends upon: | ||
+ | *#** The dose | ||
+ | *#** The virulence of the agent | ||
+ | *#* Several agents may be involved. | ||
+ | *#** Usually one agent debilitates, allowing others to exert a greater effect within the body | ||
+ | *#* The presence of an agent does not necessarily mean it is the cause of the disease! | ||
+ | *#* A pathogenic agent may be absent from the tissues, due to: | ||
+ | *#** Clinical therapy | ||
+ | *#** Host defence systems | ||
+ | *# '''Environment''', for example: | ||
+ | *#* Overcrowding of animals | ||
+ | *#* Mixing animals from differing origins | ||
+ | *#** Carriers are allowed to infect susceptible animals. | ||
+ | *#*** Carriers are animals which harbour the pathogenic agent but do not show signs of disease. | ||
+ | *#* Changes in management routine | ||
+ | |||
+ | ====Types of Agents Causing Disease==== | ||
+ | |||
+ | # '''Infectious organisms''' | ||
+ | #* [[Viruses|Viruses]] | ||
+ | #* [[Bacteria|Bacteria]] | ||
+ | #* [[Fungi|Fungi]] | ||
+ | #* [[Parasites|Parasites]] | ||
+ | # '''Physical''' | ||
+ | #* Trauma | ||
+ | #* Pressure | ||
+ | #* Heat | ||
+ | #* Cold | ||
+ | #* Radiation | ||
+ | # '''Chemical''' | ||
+ | #* Toxic organic and inorganic substances | ||
+ | #* Toxins produced by infectious organisms | ||
+ | # '''Nutritional''' | ||
+ | #* Deficiencies of vitamins and trace elements | ||
+ | #* Excess vitamins and trace elements | ||
+ | # '''Genetic defects''' | ||
+ | #* There is a very wide range of potential defects. | ||
+ | #** Some are incompatible with life | ||
+ | #** Others affect specific systems within the body | ||
+ | |||
+ | ====Aspects of Disease==== | ||
+ | |||
+ | * There are many aspects of a disease that must be considered in order to understand it in full. | ||
+ | *# '''Incidence''' | ||
+ | *#* How much of the disease is present? | ||
+ | *#* Where is the disease found? | ||
+ | *#* In what species is the disease seen? | ||
+ | *# '''Aetiology''' | ||
+ | *#* Causal agent(s) | ||
+ | *#* Predisposing factors | ||
+ | *# '''Transmission''' | ||
+ | *#* How is the disease spread between individuals? | ||
+ | *#* Is the disease zoonotic? | ||
+ | *# '''Pathogenesis''' | ||
+ | *#* How the causal agent(s) exert their effect within the body. | ||
+ | *# '''Diagnosis''' | ||
+ | *#* History | ||
+ | *#* Clinical findings | ||
+ | *#** Clinical examination | ||
+ | *#** Clinical pathology | ||
+ | *#* Biopsy or post-mortem examination | ||
+ | *# '''Prognosis and Treatment''' | ||
+ | *# '''Control and Prevention''' | ||
+ | *#* The ideal situation | ||
+ | |||
+ | ====Post-Mortem Examination==== | ||
+ | |||
+ | * Post-mortem examination (PME) investigates the observable structural changes in the animal. | ||
+ | * Information relating to the disease withing the body or specific tissue is gained from PME. | ||
+ | ** This includes information on the disease's | ||
+ | *** Aetiology (cause). | ||
+ | *** Pathogenesis (development). | ||
+ | * Several types of [[General Pathology - Post-Mortem Change|changes]] are encountered at post-mortem examination. | ||
+ | *# Those due to the '''disease''' | ||
+ | *#* Lesions | ||
+ | *# Those occuring '''immediately prior to death''' | ||
+ | *#* [[General Pathology - Post-Mortem Change#Agonal Changes|Agonal]] | ||
+ | *# Those occuring '''after death''' | ||
+ | *#* Post-mortem | ||
+ | |||
+ | ====Techniques Involved in Pathological Examination==== | ||
+ | |||
+ | * '''Fluid examination''' | ||
+ | ** E.g. blood, urine, discharges from orifices and so on. | ||
+ | * '''Cytology''' | ||
+ | ** Examination of cells in smears, aspirates and fluids. | ||
+ | * '''Necropsy''' | ||
+ | ** Visual examination of the gross changes in the dead body. | ||
+ | * '''Histopathology''' | ||
+ | ** Microscopic examination of: | ||
+ | *** Tissues selected from the dead body after necropsy. | ||
+ | *** Biopsy/excision materials from lesions in the living animal. | ||
+ | * '''Histochemistry''' | ||
+ | ** Microscopic visualisation of enzymatic activity in tissues. | ||
+ | * '''Immunological methods''' | ||
+ | ** Specific antibody activity can be detected in tissues and fluids. | ||
+ | *** Examination of serum can show prior exposure to a particular infectious agent (i.e. specifice antibodies). | ||
+ | ** Specific antigens can be detected in tissues. | ||
+ | *** When linked to a marking agent (e.g. a fluorescent dye), an antibody can localise its antigen in the tissue. | ||
+ | * '''Electronmicroscopy''' | ||
+ | ** Electronmicrosopcy shows fine detail of the surfaces or internal structures of cells. | ||
+ | * '''Bacteriology/ Virology/ Parasitology''' | ||
+ | ** These techniques allow the isolation and identification of pathogenic bacteria, viruses and parasites. | ||
+ | * '''Toxicology''' | ||
+ | ** Analysis of tissues for particular poisons and toxins. | ||
+ | |||
+ | ==General Pathology - Contents== | ||
+ | |||
+ | ===[[General Pathology - Recognition and Description of Lesions|Recognition and Description of Lesions]]=== | ||
+ | |||
+ | ===[[General Pathology - Degenerations and Infiltrations|Degenerations and Infiltrations]]=== | ||
+ | |||
+ | ===[[General Pathology - Necrosis|Necrosis]]=== | ||
+ | |||
+ | ===[[General Pathology - Post-Mortem Change|Post-Mortem Change]]=== | ||
+ | |||
+ | ===[[General Pathology - Pigmentation and Calcification|Pigmentation and Mineralisation]]=== | ||
+ | |||
+ | ===[[General Pathology - Circulatory Disorders|Circulatory Disorders]]=== | ||
+ | |||
+ | |||
+ | |||
+ | ==Inflammation== | ||
+ | |||
+ | ===Cardinal Signs=== | ||
+ | |||
+ | ===Causes=== | ||
+ | |||
+ | ===Acute=== | ||
+ | ====Introduction==== | ||
+ | ====Sequence of Events==== | ||
+ | ====Fluids==== | ||
+ | =====Serous===== | ||
+ | =====Catarrhal===== | ||
+ | =====Fibrinous===== | ||
+ | =====Diptheritic===== | ||
+ | =====Haemorrhagic===== | ||
+ | =====Purulent===== | ||
+ | =====Functions of Exudate===== | ||
+ | =====Sequel to Exudation===== | ||
+ | ====Cells==== | ||
+ | =====Neutrophils===== | ||
+ | =====Eosinophils===== | ||
+ | =====Mast Cells===== | ||
+ | =====Basophils===== | ||
+ | |||
+ | ===Chronic=== | ||
+ | ====Introduction==== | ||
+ | ====Cells==== | ||
+ | =====Macrophages===== | ||
+ | =====Lymphocytes===== | ||
+ | ====Types==== | ||
+ | =====Granulomatous Inflammation===== | ||
+ | =====Granulation Tissue===== | ||
+ | =====Lymphocytic Inflammation===== | ||
+ | |||
+ | ===Changes in Inflammatory Cells Circulating in Blood=== | ||
+ | ====Neutrophilia==== | ||
+ | ====Neutopenia==== | ||
+ | ====Eosinophilia==== | ||
+ | ====Eosinopenia==== | ||
+ | ====Lymphocytosis==== | ||
+ | ====Lymphopenia==== | ||
+ | ====Plasma Cells==== | ||
+ | ====Monocytosis==== | ||
+ | |||
+ | ===Role of The Lymph Node in Inflammation=== | ||
+ | |||
+ | ===Healing and Repair=== | ||
+ | ====Introduction==== | ||
+ | ====Repair==== | ||
+ | =====Regeneration===== | ||
+ | =====Replacement===== | ||
+ | ====In Particular Tissues==== | ||
+ | =====Skin===== | ||
+ | ======First Intention====== | ||
+ | ======Second Intention====== | ||
+ | =====Bones===== | ||
+ | =====Respiratory Tract===== | ||
+ | =====Alimentary Tract===== | ||
+ | =====Urinary Tract===== | ||
+ | =====Genital Tract===== | ||
+ | =====Central Nervous System===== | ||
+ | |||
+ | ==Disorders of Cell Growth== | ||
+ | |||
+ | ===Atrophy=== | ||
+ | ===Hypertrophy=== | ||
+ | ===Hypoplasia=== | ||
+ | ===Hyperplasia=== | ||
+ | ===Metaplasia=== | ||
+ | ===Dysplasia=== | ||
+ | ===Anaplasia=== | ||
+ | ===Neoplasia=== | ||
+ | ====Benign Tumours==== | ||
+ | ====Malignant Tumours==== | ||
+ | ====Aetiology of Tumours==== | ||
+ | ====Phases of Tumour Growth==== | ||
+ | ====Tumour Classification and Nomenclature==== | ||
+ | |||
+ | |||
+ | ==Congenital and neonatal disease== | ||
+ | |||
+ | ===Congenital=== | ||
+ | ====Causes==== | ||
+ | ====Malformations==== | ||
+ | =====Cyclops===== | ||
+ | =====Bulldog Calf===== | ||
+ | =====Cleft Palate===== | ||
+ | =====Cystic Kidney===== | ||
+ | =====Spina Bifida===== | ||
+ | =====Hydrocephalus===== | ||
+ | =====Cerebellar Hypoplasia===== | ||
+ | =====Skeletal Malformations===== | ||
+ | =====Skin Defects===== | ||
+ | =====Muscular Defects===== | ||
+ | =====Cardiac Defects===== | ||
+ | =====Sexual Organ Malformation===== | ||
+ | =====Metabolic Diseases===== |
Revision as of 19:40, 21 August 2007
An Introduction to General Pathology
- The term pathology is derived from:
- Pathos, or suffering
- Logos, or reasoning/logic.
- Pathology is defined as the study of disease including:
- Aetiology - causal factor(s)
- Pathogenesis - the development of the disease within the body.
- Lesions - the observable structural changes in the tissues and fluids of the body.
- Pathophysiology - the functional changes in diseased tissues.
- Sequel - the consequences of the disease in the body.
- Remote effects - the effect of disease in one tissue on other tissues in the body.
Lesions
- Lesions are the abnormalities or changes seen in living tissues due to disease.
- Observed in
- The live animal
- Tissues surgically removed from the live animal
- Biopsy/ excision
- Animals soon after death
- Necropsy, post-mortem examination.
Decription of Lesions
- Descriptions of lesions is very important
- Whole organs, tissues or individual lesions are described under headings such as
- Size
- Shape
- Colour
- Weight
- Generally in relation to body weight
- Texture and Consistency
- Appearance of the cut surface
- Contents of hollow organs
- Position, relationships and effects on adjacent tissues
Disease
Definition and Type
- Disease is a definite morbid (illness producing) process, having a characteristic train of symptoms or signs.
- May affect the whole body or any of its parts.
- The disease's aetiology, pathology and prognosis may be known or unknown.
- There are two main categories of disease.
- Acute
- Characterised by sudden onset and short duration.
- The outcome of acute disease may be:
- Death
- Resolution due to host defence response or clinical therapy
- Progression to chronic disease
- Chronic
- Characterised by insidious onset and protracted course.
- The outcome of chronic disease may be:
- Progressive destruction of tissue
- Compromises funtion and endangers life,
- The halting of the course of disease, with tissue repair by scarring.
- Progressive destruction of tissue
- Acute
Factors Involved in the Development of Disease
- There are three factors which conspire with each other to produce disease.
- The individual animal.
- In particular, the animal's nutritional and immune status
- This is modified by:
- Recent or concurrent disease
- Previous exposure to the agent(s) responsible
- This is modified by:
- In particular, the animal's nutritional and immune status
- The disease-causing agent(s).
- Most do not cause a uniform pattern of disease
- Host defences are important in determining the presentation of the disease.
- An agent's capacity to produce disease depends upon:
- The dose
- The virulence of the agent
- Several agents may be involved.
- Usually one agent debilitates, allowing others to exert a greater effect within the body
- The presence of an agent does not necessarily mean it is the cause of the disease!
- A pathogenic agent may be absent from the tissues, due to:
- Clinical therapy
- Host defence systems
- Most do not cause a uniform pattern of disease
- Environment, for example:
- Overcrowding of animals
- Mixing animals from differing origins
- Carriers are allowed to infect susceptible animals.
- Carriers are animals which harbour the pathogenic agent but do not show signs of disease.
- Carriers are allowed to infect susceptible animals.
- Changes in management routine
- The individual animal.
Types of Agents Causing Disease
- Infectious organisms
- Physical
- Trauma
- Pressure
- Heat
- Cold
- Radiation
- Chemical
- Toxic organic and inorganic substances
- Toxins produced by infectious organisms
- Nutritional
- Deficiencies of vitamins and trace elements
- Excess vitamins and trace elements
- Genetic defects
- There is a very wide range of potential defects.
- Some are incompatible with life
- Others affect specific systems within the body
- There is a very wide range of potential defects.
Aspects of Disease
- There are many aspects of a disease that must be considered in order to understand it in full.
- Incidence
- How much of the disease is present?
- Where is the disease found?
- In what species is the disease seen?
- Aetiology
- Causal agent(s)
- Predisposing factors
- Transmission
- How is the disease spread between individuals?
- Is the disease zoonotic?
- Pathogenesis
- How the causal agent(s) exert their effect within the body.
- Diagnosis
- History
- Clinical findings
- Clinical examination
- Clinical pathology
- Biopsy or post-mortem examination
- Prognosis and Treatment
- Control and Prevention
- The ideal situation
- Incidence
Post-Mortem Examination
- Post-mortem examination (PME) investigates the observable structural changes in the animal.
- Information relating to the disease withing the body or specific tissue is gained from PME.
- This includes information on the disease's
- Aetiology (cause).
- Pathogenesis (development).
- This includes information on the disease's
- Several types of changes are encountered at post-mortem examination.
- Those due to the disease
- Lesions
- Those occuring immediately prior to death
- Those occuring after death
- Post-mortem
- Those due to the disease
Techniques Involved in Pathological Examination
- Fluid examination
- E.g. blood, urine, discharges from orifices and so on.
- Cytology
- Examination of cells in smears, aspirates and fluids.
- Necropsy
- Visual examination of the gross changes in the dead body.
- Histopathology
- Microscopic examination of:
- Tissues selected from the dead body after necropsy.
- Biopsy/excision materials from lesions in the living animal.
- Microscopic examination of:
- Histochemistry
- Microscopic visualisation of enzymatic activity in tissues.
- Immunological methods
- Specific antibody activity can be detected in tissues and fluids.
- Examination of serum can show prior exposure to a particular infectious agent (i.e. specifice antibodies).
- Specific antigens can be detected in tissues.
- When linked to a marking agent (e.g. a fluorescent dye), an antibody can localise its antigen in the tissue.
- Specific antibody activity can be detected in tissues and fluids.
- Electronmicroscopy
- Electronmicrosopcy shows fine detail of the surfaces or internal structures of cells.
- Bacteriology/ Virology/ Parasitology
- These techniques allow the isolation and identification of pathogenic bacteria, viruses and parasites.
- Toxicology
- Analysis of tissues for particular poisons and toxins.