deck_4797640 Flashcards
What is miasma theory?
One of the first theories re: pathology, prevalent in medieval Europe, India and China. “Bad air” causes diseases such as cholera, chlamydia and black death.
What is the significance of Koch’s postulates?
Identifies the specific causative agents of tuberculosis, cholera and anthrax. Gave experimental support for the concept of infectious disease.
Definition of etiology
- the study or theory of the factors that cause disease and the method of their introduction to the host2. the causes or origin of a disease or disorder
What are the 2 major classes of factors causing disease?
- Genetic- inherited mutations and disease-associated gene variants or polymorphisms. More and more idiopathic diseases are being discovered to be genetic. 2. Acquired- infectious, nutritional, chemical, physical
What does an asymmetrical brain lesion indicate?
It is not systemic, didn’t come through the blood stream
Leuko- vs. polio-
White matter vs Grey matter
Encephalo- vs. myelo-
head vs spinal cord
Pathognomic lesion definition
A lesion that is typical for a certain agent
How many words does an etiological diagnosis have?
Two words. e.g. Cryptococcal encephalitis, traumatic fractures, etc.
What is a classical infectious disease and some examples
Infectious disease with one etiological agent and one disease (e.g. anthrax caused by bacillus anthracis, rabies caused by rabies virus)
Classical genetic disease definition and examples
Single gene disorder –> one inherited diseasePKD 1 gene –> polycystic kidney disease, osteogenesis imperfecta, spider lamb chondrodysplasia)
What is the difference between primary and secondary vitamin deficiency?
Primary vitamin deficiency- animal isn’t ingesting itSecondary vitamin deficiency- Anything else that prevents the vitamin from getting to the tissues and having effect, e.g. animal is ingesting it but there is some factor antagonizing its actions or there is malabsorption of the vitamin or the disease isn’t being processed correctly.
What is an example of One etiological agent –> Multiple diseases
Vitamin E deficiency (and excess intakes of polyunsaturated fatty acids, because these antagonize Vitamin E) can cause tons of different diseases any many different species.
EDx and MDx of this lesion? How would this happen?
EDx: Traumatic fractureMDx: Ventral fracturesFractured skull of a horse and fractured scapula of a horse.This can happen if they fall back and hit their head on a wall. Bleeding within the cranial cavity results in more severe and quicker changes because of space available
Description of lesionEtiology and method of diagnosisEDx
Description: Cavitational lesions, bilateral asymmetrical (pathognomonic lesion for EDx). Thalamus, cerebellum and mesencephalon of a cat shown intransverse sections.Etiology and method of diagnosis: Cryptococcus neoformans found by histopathEDx: Cryptococcal encephalitis
What is malasia?
Necrotic brain tissue
Lesion description:Dx:Etiology:
Lesion description: Spine of suffolk lamb, longitudinal section. Multiple disorganized ossification centered resulting in variation of the size, shape and orientation of the vertebrae.Dx: Spider lamb chondrodysplasiaEtiology: Single base change in the tyrosine kinase II domain of FGFR3
Lesion description:MDx:Dx:Etiology:
Description: Grossly diffuse, non-homogeneous- pink, red, black and greyish color. Histopath- central and mid-zonal areas are hemorrhagic and the hepatocytes that are being replaced are necrosing. The border cells are the functioning ones. Not a true hepatitis bc there is not an excessive amount of inflammatory cells on histopath.MDx: Diffuse hepatocellular necrosis and hemorrhageDx: Hepatosis dietetica (nutritional hepatic necrosis)Etiology: Deficiency of Vitamin E and/or Selenium
Description of lesion:Dx:Causes:
Description of lesion: Focal gastric ulcer with some hemorrhage in the stratified squamous epithelium is surrounding the cardia (pars esophagea) of the stomach of a pig.Dx: Gastric ulcer (pars esophagea), aka ulcerative/necrotizing gastritisCauses: Ingestion of finely ground grain or pelleted feed (possibly deficient in vitamin E). Fermentation of sugars in the feed (increases acidity). Stress of confinement rearing (common bc pigs lower in hierarchy are stressed). Helicobacter pylori overgrowth. Common in growing pigs.
Definition of ulcer
An ulcer is a deep necrotizing lesion in a tubular organ. When more superficial, it is called erosion.
What causes of death lead to fulminating pulmonary edema in animals? Why?
Sepsis, Toxemia, Aspiration of gastric contents, PancreatitisAll –> hyperreactive macrophages –> directly or idirectly generate overwhelming amounts of cytokines –> some cytokines prime neutrophils stationed in the lung capillaries –> release of enzymes and free radicals –> diffuse endothelial and alveolar damage –> pulmonary edemaSyndrome analogous to ARDS/ shock lung (acute/adult respiratory distress syndrome) in humans
What are some examples of autoimmune diseases that are caused bymultifactorial diseases?
Systemic lupus erythematosusType III hypersensitivity
What is the difference between having multiple etiologies and multiple factors? Give anexamples of each.
Multiple etiologies: Bovine respiratory disease complex. Can be caused by pneumonic mannheirniosis (Mannheimia haemolytica), respiratory histophilosis (Histophilus somni), etc.Can also have multiple steps (first stage primary agents and second stage opportunistic bacteria)Multiple factors: Pneumonias of pigs. Factors include host, infectious agents, environmental determinants, mgmt practices, etc.
What are the 5 main types of pathological processes?
What are the 8 main types of etiologies?
Description of lesion:Dx:
Description of lesion: Squamous metaplasia of the esophagus of a parrot. The raised white plaques are keratin.Dx: Avitaminosis A (a type of disease of adaptation, degeneration and cell death)
Dx if inflammatory cells are found on histology:Etiology:
Dx: Embolic nephritis (kidney of horse) (a type of disease of inflammation and repair)(Embolic means a descending type of infection coming from the blood stream. Initially goes in the cortex)Etiology: Caused by Actinobacillus equuli
MDx:Etiology:
MDx: Congenital porphyria of cow bone (a type of tissue deposit/pigmentation)Etiology: Defect in heme synthesis caused by a deficiency in uroporphyrinogen III cosynthetase
Dx:Causes:
Dx: Chronic passive congestion (nutmeg liver) of liver of a cow (a type of circulatory disorder)Causes: right sided heart failure, ingestion of hepatotoxin (i.e. Wedelia glauca, etc.)
Dx:Etiology:
Dx: Globoid cell leukodystrophy of a dog (a type of Lysosomal storage disease, type of genetic disorder)Etiology: Defect in an enzyme (galactosylceraminidase)
MDx:Etiology:
MDx: Acute allergic rhinitis with secondary plant foreign body (disease of immunity, lupus is also an example of this)Etiology: Type I hypersensitivity reaction- plant allergen
Dx:Etiology:
Dx: Bovine abomasal lymphoma (type of neoplasia)Etiology: Bovine leukemia virus
Dx:Etiology:
Dx: Epithelial plaques, papular stomatitis of the hard palate mucosa of a calf (type of microbial infection)Etiology: Parapoxvirus
What is the DAMNIT-V scheme?
What are idiopathic diseases? Name some examples.
Diseases of unknown cause or spontaneous originEpilepsy, hypertrophic cardiomyopathy, renal amyloidosis, canine polyarteritis, pulmonary fibrosis, laryngeal hemiplasia
Define cell adaptation and give examples.
Occurs when the cell homeostasis is distorted by stresses or pathologic stimuli. The cell is not dead, just morphologically different from the normal cell. Can return to normal morphology and homeostasis when the stress is removed.Cells preserve viability and function.Reversible change!Principles responses of adaptation are: atrophy, hypertrophy, hyperplasia, metaplasia
Define homeostasis
Tendency to stabilize the normal body states of the organism;it is the ability to maintain internal equilibrium by adjusting its physiological processes
Define and give causes and examples of atrophy
Decrease in size and/or number of the cells and their metabolic activity after normal growth has been reached. Remember, cells are not dead. They are still functioning, just smaller.Decreases protein synthesis and increases protein degradationCauses: decreased workload, denervation (e.g. recurrent laryngeal nerve denervation –>laryngeal atrophy), decreased blood supply or oxygen, inadequate nutrition, loss of endocrine stimulation, agingExamples: muscle disuse of limb in cast, sedentary atrophy, adrenal cortex atrophy by reduction of ACTH stimulation (steroid therapy), atrophy in tissues adjacent to a tumor due to pressure and compromised blood supply, physiologic atrophy (e.g. non-lactating mammary gland atrophy), serous atrophy of heart or bone marrow(lack of fat, dilated lymphatics)