Intro Flashcards
What is pathology
the study of signs of diseases and mechanisms that underlie disease. It includes the study of the functional and morphological changes in the tissue and fluids of the body during disease.
What is disease?
a condition of the living animal or plant body or of one of its parts that impairs normal functioning and is typically manifested by distinguishing signs and symptoms
Functional and morphological changes
Functional changes are changes in the function of an organ. The structure of the organ might remain normal.
Morphological changes are changes in the actual structure of an organ.
What is a lesion?
A lesion is an abnormal change in structure of an organ or part due to injury or disease
Clinical symptoms
The discomfort or pain due to a disease or injury that is felt by the patient.
Clinical signs
a medical condition that can be observed by the clinician/pathologist.
Aetiology
the cause of the condition/disease – bacteria, virus, protozoa, unusual food,
toxins, sudden change of diet etc.
Pathogenesis
the sequence of events from the point at which the lesion began through
its entire development. A step by step progression from the normal stage through to the abnormal structural or functional state.
Pathognomonic
A sign/symptom/lesion that is so characteristic of a disease that it can be used to make a diagnosis. E.g. Negri bodies for rabies
Diagnosis
this is the process of identifying a disease by its signs, symptoms and results of various diagnostic procedures.
Types of Diagnosis
Morphological
Aetiological
Tentative
Differential
Definitive
Morphological diagnosis
this is a type of diagnosis that involves naming the lesions.
Aetiological diagnosis
this is the type of diagnosis that involves naming the cause of the disease.
Tentative diagnosis
this is the type of diagnosis that involves naming your suspected cause of the disease, or a temporal diagnosis based on all the clinical signs, symptoms and lesions.
Differential diagnosis
this is a list of diseases that have similar signs to what the animal is exhibiting.
Definitive diagnosis
this is the naming the specific disease entity. This is normally done after conducting several tests to rule out or confirm what you had put as tentative and differential diagnosis.
Necrosis
refers to the “morphological changes caused by the progressive degradative action of enzymes on the lethally injured cell within the living body”.
After a cell dies, lysosomes rupture and their hydrolytic enzymes are released.
The release and activation of these lysosomal enzymes are responsible for cell necrosis. Simply, necrosis is defined as “localised cell death in a living individual”.
Postmortem changes
refer to cell death which accompanies or occurs after death of the
entire body (somatic death).
Antemortem changes
refer to those alterations that occur in cells, tissues, organs, etc. before somatic death or in the living individual.
Post-mortem autolysis
refers to self-digestion by enzymes that are present within or released into the cytoplasm of cells after death. It is due to total diffuse anoxia.
Post-mortem putrefaction
refers to the decomposition of tissues by bacterial enzymes after death of the entire body
Rigor mortis
refers to stiffening of all muscles after death. It is related to a progressive decrease in oxygen, ATP, creatinine phosphate, and pH of muscles. Thus, muscle fibres shorten as they pass into rigor. Classically, rigor mortis begins in one to six hours after death and disappears 24 to 48 hours later.
Livor mortis
refers to the discolouration of dependent parts of the body after death as a result of red blood cell destruction. It is seen as the “gravitational settling of blood” in the lower (dependent) parts of the body after death.
Algor mortis
refers to the cooling of the body after death.
