Intro to pathology Flashcards
What is general pathology?
What is systemic pathology?
pathology of organ systems
What is aetiology?
cause of disease
What is pathogenesis?
mechanisms of disease development
What are the major processes of pathology?
inflammation
healing
thrombosis
neoplasia
metabolic dysfunction
necrosis
Define anatomic pathology
Define clinical pathology
Define pathology
The study of the structural, biochemical, and functional changes in cells, tissues and organs that underlie disease
What is clinical manifestation?
Functional consequences of molecular and morphologic changes
Give examples of internal aetiology?
age
immunological defects
genetic defects
Give examples of external aetiology
Agents:
- physical
- chemical
- biological
Deficiencies:
- nutritional
- environmental
What are molecular and morphological changes?
Molecular changes: Biochemical alterations in cells or tissues – alter function
Morphological changes: Structural alterations in cells or tissues
Define inflammation
Vascular and interstitial tissue changes that develop in response to tissue injury and that are designed to sequester, dilute, and destroy the causal agent
What are the signs of inflammation?
heat
redness
swelling
pain
loss of function
Describe the process of wound healing
It involves angiogenesis (formation of new blood vessels), fibrosis (formation of fibrous connective tissue by fibroblasts), and regeneration.
Epithelisation is the regenerative process that covers defects in injured skin and other epithelial surfaces
Describe thrombosis
Interaction of the blood coagulation system and platelets to form, within a vascular lumen, an aggregate of fibrin and platelets
What is the difference between thrombosis and a blood clot?
Thrombosis = before death
Blood clot = after death
Describe metabolic dysfunction as pathological
Abnormalities or imbalances of carbohydrate, fat, and protein metabolism in the cell lead to accumulation of glycogen, lipid, or protein as well as complexes of abnormally folded and branched proteins, pigments, lipoproteins, and amyloid.
Define biopsy
Removal and examination of a tissue sample from a living animal body for diagnostic purposes
Define necropsy
Methodical examination of the dead animal
Define diagnosis
Conclusion concerning the nature, cause, or name of a disease
Define lesions
Abnormal structural and functional changes that occur in the body
What are the different types of diagnoses?
Clinical diagnosis
Clinical pathologic diagnosis
Morphologic diagnosis (‘lesion’ diagnosis)
Aetiologic diagnosis
Disease diagnosis
Describe clinical diagnosis
Based on data obtained from the case history, clinical signs, and physical examination
Describe clinical pathologic diagnosis
Based on changes observed in the chemistry of fluids and the haematology, structure, and function of cells collected from the living patient
Describe morphologic diagnosis
Based on the predominant lesion(s) in the tissue(s)
- macroscopic lesions (gross)
- microscopic lesions (histologic)
What is aetiologic and disease diagnosis?
Aetiologic: Names the specific cause of the disease e.g., PCR
Disease: states the common name of the disease
What are the 2 methods for detecting morphologic changes?
macroscopic examination
Microscopic examination
What is macroscopic examination?
observations made by the unaided eye
Observing deviations in size, colour, texture and location of normal organs and tissues
What are methods of microscopic examinations?
Light or Electron microscopy
Give examples of molecular techniques used in diagnosis
Polymerase chain reaction (PCR)
In situ hybridization (ISH)
Genomics (DNA sequencing, DNA microarrays)
Transcriptomics (RNA sequencing)
Proteomics
Metabolomics
Immunological approaches - immunostaining/immunohistochemistry
What is the function of PCR?
to detect (or detect alterations from normal in) nucleic acid (DNA/RNA) and protein
Give examples of normal post-mortem changes
Rigor mortis
Algor mortis
Livor mortis (hypostatic congestion)
Post-mortem clotting
Haemoglobin imbibition, bile imbibition
Pseudomelanosis
Bloating
Softening
Lens opacity
Give examples of normal (non-lesion) post-mortem changes
Post-mortem autolysis
Putrefaction
What is putrefaction?
Colour and texture changes, gas production, and odours that are caused by post-mortem bacterial metabolism and dissolution of host tissues (post-mortem decomposition)
What is rigor mortis?
Contraction of muscles after death due to depletion of ATP and glycogen
What is algor mortis?
Gradual cooling of the cadaver
What is livor mortis (hypostatic congestion)
Gravitational pooling of blood to the lowest side of the animal
What is haemoglobin imbibition?
Integrity of blood vessel walls is lost => haemoglobin released by lysed erythrocytes penetrates the vessel wall => red staining of tissue
What is bile imbibition?
Bile in the gallbladder penetrates its wall and stains adjacent tissue yellowish/greenish/brown
What is pseudomelanosis?
Blue-green discoloration of tissue by iron sulphide (FeS)
Hydrogen sulphide (from putrefactive bacteria) reacts with haemoglobin from lysed erythrocytes
What is the cause of post-mortem bloating
post-mortem bacterial gas formation in the lumen of the GI tract
What is the cause of post-mortem softening?
results from autolysis of cells and connective tissue often aided by putrefactive bacteria
When does post-mortem lens opacity occur?
Occurs when the carcass is very cold or frozen
the change will reverse to normal transparency on warming
