Introduction to Pathology Flashcards
What is disease
Any harmful devation from or interruption of any part or system of the body which is manifested by a characteristc set of symptoms (what the patient feels) and signs (what the clinician sees)
What is Pathology
‘Study of disease’
The structural, biochemical and functional changes in cells, tissues and organs that occur in disease
Importance of pathology
Fundamental to understanding how a disease occurs and how disease can be diagnosed, treated and prevented
General Pathology
Basic responses of cells and tissues to insults and injuries, irrespective of the organs, systems, or species of animal involved
Systemic Pathology
Pathology of organ systems
Alterations in specialized organs and tissues
Anatomic Pathology
Examination is tissues taken during life (biopsy) or after death (autopsy, necropsy)
Can be gross or histopathology
-> examines nature and extent of disease process
Clinical Pathology
Examination of blood and other body fluids, as well as (cytology) during life, laboratory diagnostics and technology
What is aetiology
Cause of the disease
What is pathogenesis
How the disease develops
4 aspects of disease
Aetiology, pathogenesis, molecular and morphological changes, and clinical manifestation
What is 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
‘-itis’
What is healing
Repair of injured tissue, occurs after or during inflammation
Angiogenesis
Formation of new blood vessels
Fibrosis
Formation of fibrous connective tissue by fibroblasts
Which organs will undergo regeneration
Some organs such as intestines will generate, stable organs such as the heart will not
Epithelisation
The regenerative process that covers defects in injured skin and other epithelial surfaces
Thrombosis
Interaction of the blood coagulation system and platelets to form, within a vascular lumen, an aggregate of fibrin and platelets (=thrombus)
What is neoplasia
Cancer- can be benign or malignant
Intrinsic genetic mutation in somatic cells that underlie abnormal mechanisms for growth and control of mitosis, differentiation and cell-to-cell interactions, all of which lead to unrestrained mitosis
Disruption of normal cell boundaries -> abnormal cell growth
leads to disruption of normal tissues through replacement or compression
Metabolic dysfunction
Metabolism is the chemical process that takes place in an organism in order to maintain homeostasis
Dysfunctions can be genetic, due to a chemical imbalance, or an organ malfunction (e.g. pancreas in diabetes)
Necrosis
Death of cells or tissues in the living animal, can be diffuse or just part of an organ affected
What is a biopsy
Removal and examination of a tissue sample from a living animal body for diagnostic purposes
Post mortem exam
Methodical examination of the dead animal
What is the Pathological Description
How to describe lesions observed during the biopsy or autopsy
What is included in the pathological description (8)
Location
Number/ extent
Demarcation- can you tell the lesion apart from normal tissue
Distribution
Colour
Size
Shape
Consistency and texture
* smells or sounds should also be recorded
What does varrucose mean
wart like shape
How to describe distribution of pathology
Focal, multifocal, focally extensive, multifocal to coalescing, diffuse (entire organ), random, segmental etc.
What is a clinical diagnosis
Based on data obtained from the case history, clinical signs and physical examination
what is a clinical pathological diagnosis
Based on changes observed in the chemistry of fluids and the haematology, structure, and function of cells collected from the living patient
e.g. azotaemia, hypernatremia etc
What is a morphological diagnosis
Based on what is seen- the predominant lesions in the tissues
Can be microscopic/histological or macroscopic/gross
What does the morphological diagnosis describe (5)
Location (organ)
Distribution- Focal, multifocal, diffuse, segmental
Severity- mild, moderate, severe
Duration- peracture, acute, subacute, chronic
Nature/ Process - degenerative, inflammatory, neoplastic (indicated by -itis, -osis …..)
What is morphology
Study of what can be seen through microscopis and/or macroscopic examination
Macroscopic examination of morphology
Observe deviation in size, colour, texture and location
What is autolysis, when does it occur
changes due to “self-digestion”, intracellular enzymes leak through cell membranes
Post mortem
What is putrefaction, when does it occur
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 and why does it occur
Contraction of muscles occurring after death
Due to depletion of ATP and glycogen, commences 1 to 6 hours after death and persists for 1 to 2 days
What is livor mortis
Gravitational pooling of blood to the down side of the animal, can be seen on skin or in organs
What is haemoglobin imbibition
Red staining of tissues
Once the integrity of blood vessel walls is lost, haemoglobin released by lysed erythrocytes penetrates the vessel wall
What is bile imbibition
Bile in the gal bladder stains adjacent tissue yellow/green/brown
What is pseudomelanosis
Blue-green discolouration of the tissue by iron sulphide (FeS)
formed by the reaction of hydrogen sulphide (H2S) generated by putrefactive bacteria and the iron from haemoglobin released from lysed erythrocytes
What to include in morphological diagnosis of neoplasia and malformations
Organ + Name of neoplasia/malformation
What does per acute mean
v. quick-> quicker than acute
What is agonal
Abnormal pattern of breathing characterised by laboured, gasping breaths that occur because of insufficient oxygen.
