Introductory Veterinary Pathology Flashcards
Describe cellular dysplasia.
Alteration in the size, shape or organization of a tissue
What is aplasia?
Organ does not develop at all and only rudimentary tissue is present
What is agenesis?
Failure of any development due to lack of embryonic primordial tissue
Describe hydropic degeneration.
- Cellular injury
- Reversible
- Often results from hypoxia as reduced ATP levels cause cell to switch to anaerobic metabolism causing depletion of glycogen and accumulation of lactate and inorganic phosophates which inhibits membrane sodium/potassium pump and water moves into the cell
- Characterized by cytoplasmic swelling and extensive vaculolation which does not histopathologically stain for fat (Oil Red O) or glycogen (Periodic Acid-Schiff Stain)
- Can progress to ‘Ballooning Degeneration’
What is oncotic necrosis?
Swelling of cell due to excessive water entry (hydropic degeneration) and subsequent cellular death
Describe coagulative necrosis.
- Cell death typically caused by ischemia or infarction.
- The architecture of dead cells is preserved for at least a couple of days.
Describe caseous necrosis.
- Form of cell death in which the tissue maintains a cheese-like appearance. The dead tissue appears as a soft and white proteinaceous dead cell mass.
- Evidence of chronic lesion
- May develop dystrophic calcification
- On microscopic examination with H&E staining, it is characterized by acellular pink areas of necrosis surrounded by a granulomatous inflammatory process.
Decribe gangrenous necrosis.
- Type of necrosis caused by a critically insufficient blood supply
- Grossly, tissues appear black in colour
What is dystrophic calcification?
- Calcification occurring in degenerated or necrotic tissue
- It occurs in areas of cell necrosis in which activated phosphatases bind calcium ions to phospholipids in the membrane.
What is Karyorrhexis?
The breaking of nuclei into pieces.
What is pyknosis?
The apparent shrinking of the cellular nucleus upon microscopic investigation
Describe lipidosis.
- Intracellular (intracytoplasmic) accumulations of fat. The liver is susceptible because of its central role in lipid metabolism
- Mechanisms
- Excessive free fatty acids from diet or adipose tissue breakdown
- Toxic damage affecting metabolism of fatty acids and triglycerides
What is fatty infiltration?
- Replacement of cells by adipocytes
- Can occurs because of old age or obesity
What is hameosiderin?
Iron storage complex found in red blood cells
What is an empyema?
- the collection of suppurative/ purlent inflammatiory fluid (pus) in a cavity in the body
- Dominated by neutrophils, both dead and alive
- Contains dead host cells
- Often caused by bacteria
- May become walled off by granulation or fibrous tissue causing an abcess
How does fibrinous inflammation occur?
- Forms as a result of increased vascular permeability and fibrinogen escape from the vascular system which polymerizes to fibrin by thrombin
- Acute phenomenon
Describe mucus/catarrhal inflammation.
- Caused by mucus hypersecretion which accompanies inflammation
- Often found in respiratory and gastrointestinal tracts where mucus-secreting cells are prominent
Describe this gross pathology.
Caseous necrosis in the pleura
What cell is this?
Eosinophil of a horse
Describe the prominent process occuring
Erythrophagocytosis
Describe the process occuring
Fatty infiltration of the muscle fascicle
Describe the gross pathology
- Fibrinous inflammation
- Acute phenomenon which occurs as a result of increased vascular permeability and fibrinogen escape from the vascular system which polymerizes to fibrin by thrombin
What cell type is pictured here?
Fibroblasts
Describe this process
Fibrosis of the liver
Describe this process
- Gangrenous necrosis of a pig’s ear
- Occurs with infarct
- Follows on some cases of coagulative necrosis
What cell is pictured here?
Giant cell
What cellular process is pictured here? What stain was used?
- Glycogen accumulation in the cells of the proximal tubule
- Periodic acid-Schiff (PAS) was used to detect the glycogen polysaccharide
What stain is being used in this slide and what is being depicted?
- Gram stain to visualize bacteria
- Gram negative bateria stain pink
- Gram positive bateria stain purple
What stain is being used in this slide and what is it depicting?
- Jones stain which visualizes basement membranes
- This is a slide of the kidney
What process is being depicted here?
Karryohexis
What process is being depicted here?
Karyolysis
What process is being depicted here/
Lipidosis of the liver
What cell is being depicted here?
Lymphocyte
What cells are being depicted here?
Macrophages
What histological stain is being used and what is it depicting?
- Mason’s trichrome stain of the liver
- Stains connective tisse in green
What cell is being depicted here? Describe some of its characteristics.
- Mast cell
- derived from the myeloid stem cell. It is a part of the immune and neuroimmune systems and contains many granules rich in histamine and heparin
What cells are being depicted here?
- Neutrophils
What stain is being used in this histological slide and what is it depicting?
Oil red O stain highlighting lipid in red
What stain is being used in the following histological slide and what is it depticting?
Periodic acid-Schiff (PAS) stain of the kidney for visualizing glycogen
Describe the appearance of karyolysis histologically. What causes this?
Karyolysis appears histologically as a nucleus which fades into the background. This is caused by the complete dissolution of the chromatin of a dying cell due to the enzymatic degradation by endonucleases.
What stain is being used here and what does this stain highlight?
- Perl’s Prussian Blue reaction stains is being used which stains haemosiderin (blood breakddown product) blue
- This particular slide is depicting hepatocytes
What pathology is being shown here?
Purulent and suppurative exudate of the thorax
What process is depicted here?
Pyknosis: the shriking of the cell nucleus
How can this group of cells be described?
- Pyogranulomaous inflammation: inflammatory process in which there is infiltration of polymorphonuclear cells into a more chronic area of inflammation characterized by mononuclear cells, macrophages, lymphocytes and possibly plasma cells
- This particular side is of an infected lymph node
What stain is being used here and what structure is/are being highlighted?
- Toluidine blue stain is used to visualize acidic structures
- Immune cell graunlocyte granules will appear blue histologically upon staining
What stain is being used in this histological slide and what is it hightlighting?
- Ziel-Neilson stain for mycobacteria mast cell granules
- This particular slide is of a sputum sample
Describe the following lesions
Depressed
Describe the following lesion
Diffuse