Objectives for Exam 1 Flashcards
define pathology
study of disease
Define disease
abnormal body process with or without characteristic sign. It begins at the molecular & cellular level. It can be said that it is any deviation from the normal structure or function of the body.
Define Etiology
- cause of a disease.
- Two major causes: genetic (intrinsic) & acquired (extrinsic)
Define Pathogenesis
- refers to the mechanisms of disease development
- sequence of events from INITIAL stimulus to the ULTIMATE expression of the disease
Define morphologic diagnosis (MDx)
- biochemical & structural alterations induced in the cells and organs of the body.
- based on the predominant lesion(s) in the tissue(s)
How does one make a Morphologic diagnosis (MDx)?
Via Macroscopic & Microscopic evidence found, using the following descriptions:
1) location (organ tissue)
2) Distribution (focal, multifocal, locally extensive, diffuse)
3) Severity (mild, moderate, severe)
4) Duration/time (acute or chronic)
5) Nature of lesion (degenerative, inflammatory, neoplastic)
If inflammatory remember to classify the type of exudate
Define Pathognomonic
characteristic or indicative of a specific disease
Define Prognosis
refers to the course of the disease= possible outcome
Define clinical diagnosis
- based on case history (Hx), clinical signs, physical exam.
- may provide differential Dx
Define etiologic diagnosis (Edx)
it is a more definitive Dx and names the specific cause(s) of the disease
Define differential diagnosis
list of diseases that could account for the evidence or lesions of the case
Define homestasis
ability to maintain equilibrium by adjusting its physiological processes
What is somatic death?
- it is due to total diffuse hypoxia
- cells degenerate as described for hypoxic cell injury
What is putrefaction/decomp?
- process by which post mortem bacteria break down tissues
- gives color, texture changes, gas production, & odors
In general, what kind of organs undergo autolysis faster than others? Give examples
- organs that normally contain enzymatic activity or have high bacteria content
- pancreas, GI tract, & gallbladder
What is the difference between autolysis & decomposition?
- autolysis: self digestion of cells & tissues by OWN hydrolytic enzymes normally found in tissues
- decomp: post mortem bacteria break down tissues
Herbivore vs. Carnivore. Which will decompose faster?
herbivore
When is the onset of Rigor Mortis?
begins @ 1-6hrs post death, persistent 1-2 days
How would you test if an animal has anthrax before performing a necropsy?
take notch off ear or tail, stain the tissue, see if you have bacillus in blood, if so = anthrax. Normally a freshly dead animal shouldn’t have bacillus in the blood yet.
What are some factors that could make quicken the onset of rigor mortis?
high stress, high heat, & high activity before death
What is Algor Mortis?
cooling of body post mortem, depends on T of body @ time of death
What are some big indicators that a carcass may be infected with anthrax?
absence of rigor mortis, Bleeding from every orifice, bloated
What is Livor Mortis? What is another name for it?
- hypostatic congestion
- gravity pulls blood post mortem, some areas the tissues will be more red and in other areas pale due to lack of blood. ONLY A POST MORTEM CHANGE!
Describe Post Mortem clotting.
- occurs several hrs post death in heart & vessels.
- usually clots are unattached to vessel walls and are shiny, wet, and are a perfect cast of vessel lumina (like jello!)
Describe Pre Mortem clots.
usually attached to vessel walls and are dry & duller in color, “laminated”.
How is clotting affected when it comes to autolysis.
- in moderate–> severe : you will NOT see clotting
- in light –> moderate : you WILL see clotting
- usually will see clotting in heart regardless of autolysis.
What is hemoglobin imbibition?
red staining of tissue, especially in the heart, arteries & veins. Color may spread to adjacent tissues.
What is bile imbibition?
bile in gallbladder starts to penetrate the wall & stain the adjacent tissues yellowish to greenish brown.
What tissues are usually stained with bile imbibition?
those in contact with bladder: liver & intestines & feces.
Describe Bloat.
results from post mortem bacterial gas formationin the lumen of the GI tract
How does one differentiate bloating from ruminal tympany?
if animal died from tympany then the animal would have a bloat line on the esophagus & trachea. This occurs b/c blood gets cut off by the stomach pushing on it and blood starts backing up in that area. You wont see this is bloat was post mortem.
How can you differentiate clouding of the lens due to temperature vs. cataracts?
once the carcass goes back to room temp the lens will no longer be clouded if it is just due to being chilled.
What is Pseudomelanosis?
- refers to greenish-black discoloration of tissues post mortem.
- caused by decomp of bloody by bacterial action forming hydrogen sulfide w/ iron
- occurs soon after death, closer to the gut the faster it will change color
What is the mnemonic for differential diagnosis?
DAMNIT D = degenerative A = Autoimmune M = Metabolic N = Nutritional, neoplastic I = inflammatory, idiopathic, iatrogenic T = trauma
Define hypoxia
inadequate oxygenation of tissues
Define Ischemia
decrease of blood supply in tissues
Define anoxia
absence of oxygen in tissues
Define Anemia
decrease in number of RBCs, or RBCs are deficient in Hb, or decrease in BV.
What are the general causes of cell injury? (6)
1) Oxygen deprivation
2) Physical injury (direct mechanical trauma, Temp extremes)
3) Chemical injury (poisons or toxins)
4) Infectious agents (bacteria, viruses, fungi, parasites)
5) Nutritional imbalances (deficiency (vitamin E/selenium), excess)
6) Genetic (mutations)
Describe irreversible cell injury.
“the point of no return” occurs when the injury reaches a certain limit, whereby the cell cannot recover.
What are the 6 intracellular systems vulnerable to injury?
1) cell membrane
2) aerobic respiration
3) protein synthesis
4) cytoskeleton
5) genetic apparatus (DNA)
What are the 6 general mechanisms of cell injury?
1) ATP depletion
2) Mitochondrial damage
3) Influx of Ca
4) Accumulation of Oxygen-derived free radicals (Oxidative stress)
5) Defects in membrane permebility
6) DNA damage
What is the difference between atrophy & hypertrophy?
atrophy is a decrease in size from lack of use & hypertrophy is the cells increase in size in order to increase its function.
What is the difference between hyperplasia, dysplasia, & metaplasia?
- hyperplasia: is the increase of number in cells
- dysplasia: abnormal development of cells
- metaplasia: cells changing its phenotype in response to chronic irritation (ex. Smokers lung)
List some stages of cell response to stress or injury.
atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia.
List conditions resulting from physiological cell adaptation
weightlifting
List some conditions resulting from pathological cell adaptiation
thickening of skin, smokers lungs
Describe reversible cell injury
- alteration of homeostasis
- return & recovery to normal when the stress or injurious stimuli are removed
Define Atrophy
decrease in size and/or number of cells & their metabolic activity after a normal growth has been reached (note: cells still viable & functional)
Give some examples of physiologic atrophy.
muscle disuse in a limb that is in a cast
Give some examples of pathologic atrophy.
atrophy in tissues adjacent to a tumor due to pressure & compromised blood supply or serous atrophy of fat
What are some causes of atrophy?
decrease workload, blood supply, or oxygen, denervation, inadequate nutrition, loss of endocrine stimulation, aging.
What causes atrophy of the left cricoarytenoideus dorsalis m. in horses & dogs?
- Horses: due to damage to LEFT recurrent laryngeal n. from guttural pouch infection, trauma, tumors, but mostly idiopathic. COMMON secondary to nerve damage.
- Dogs: inherited in Siberian Husky & Bouvier de Flandres
When does serous atrophy of fat happen?
When an animal has a negative energy of fat, in order to compensate body uses stored fat.
