Week 1: Causes of Disease Flashcards
Pathology
Study of disease. Study of the structural and functional changes in cells, tissues, and organs that are caused by disease.
Clinical pathology
The study of the cause, mechanisms, and effects of the disease.
Experimental pathology
Experimental studies on tissues, cell cultures, or animal models.
Cytopathology
Examination of isolated cells.
Histopathology
Examination of tissues.
Surgical pathology
Histologically examining surgical tissue specimens from biopsies to determine the nature of the disease.
Gross pathology
Taking samples from tissue and examining them with light microscopy and electron microscopy at cellular and molecular levels.
Special stains
Special stains identify elastic tissues, veins, and abnormalities.
Immunohistochemistry
Uses primary antibodies that recognize antigen of interest (i.e. CDX2). A secondary antibody has a linker system that recognizes the primary antibody.
Brown = positive
Molecular testing
Identifies the genetic characteristics of a disease (i.e. genes involved in tumours)
What is a disease, and when does it occur?
It is any deviation from the normal function/structure of tissues, organs, or systems. Disease occurs when cells fail to adapt to injury, or when the adaptation is harmful.
Injury
Due to disturbances from physical/chemical agents.
Reversible: cell/tissue survives or adapts
Irreversible: leads to death or degeneration of the cell
Inflammation
Common response to disease following injury or infection. Some diseases are primarily inflammatory (e.g. tonsilitis).
Chronic inflammatory response occurs in allergic reactions or viral/parasitic ones.
Infection
One of the most common forms of disease. Usually produces mild to moderate symptoms. Infectious organisms (i.e. viruses, bacteria, parasites) can produce more serious illness in immunocompromised individuals.
The extent of cellular pathology and disease depends on factors of both the attacking organism and host’s responses.
Immunological Reaction
Immune response is normally protective, but in some circumstances the reaction may become
- Excessive (e.g. hypersensitive to allergens - anaphylactic shock)
- May act against the body’s own cells (e.g. autoimmune disease - thyroiditis, myasthenia gravis),
- May be absent or depressed (e.g. severe combined immunodeficiency disease, immunosuppressive therapy).
Neoplasia
Autonomous proliferation of cells, usually causing tumours or masses. Can be benign or malignant.
Metabolic or Endocrine disease
Disorders of enzymes, hormones, or secretory products (e.g. DM2). Some metabolic diseases are genetic (e.g. congenital adrenal hyperplasia)
Nutritional disease
- Deficiencies in proteins or calories due to insufficient supply; decreased transport, absorption, or utilization, or specific vitamin; or mineral deficiencies.
- Excess calories/obesity increases risk of a number of conditions.
Vascular disease
One of the most common causes death in developed countries. Abnormalities in blood vessels.
Narrowing of important blood vessels (atherosclerosis) underlies common causes of morbidity and mortality (heart attacks, strokes).
Psychological factors of disease
Psychological stress may cause and affect disease processes and can lead to mental illness or worsen the existing somatic disease.
Also an important factor in disease caused by addiction
Physical signs of disease
Objective evidence
EX Blood in stool
Symptoms of disease
Subjective evidence of disease (what the patient tells you)
EX “I have stomach pain”
Genetic insults and causes of disease
Includes single mutations to large alterations to chromosomes. May be congenital or acquired.
Inherited genetic causes are rare; it is more common to have sporadic mutations to DNA throughout life
Not all inherited genetic diseases manifest at birth; Huntington’s Chorea is not seen until adulthood
Not all congenital diseases are genetic; infections can result in heart defects, cataracts, microcephaly, etc)
Environmental insults/causes of disease
Physical or chemical agents (i.e. drugs)
Iatrogenic (i.e. adverse event as a result of treatment)
Allergens
Personal/lifestyle habits (i.e diet, exercise, weight control, smoking)
Iatrogenic disease
Diseases that are caused by medical therapy. Unintended injuries or complications resulting in death, disability, or prolonged hospital stays from health care management
Etiology
Cause of a disease process.
Allow us to understand causes of disease to avoid/be educated about (i.e. hepatic cirrhosis can be caused by viruses, alcohol, storage disorders)
This may also include cause of death in autopsy context (i.e. head trauma caused by MVC)
Idiopathic disease = unknown etiology
Complications and sequelae
Secondary consequences of disease or procedure (i.e. post-op infection)
Morbidity
Illness that impairs well-being and normal function of patient (living with disease)
Mortality
Death; differs within age groups (death from disease)
Pathogenesis
Development of a given disease; the sequence of cellular events that take place from time of initial contact with the etiologic agent to the expression of the disease.
Mechanism/how the disease evolves
Pathological and morphological manifestations
Pathological: Changes in structure and function of tissues, organs, and systems.
Morphologic: Changes are anatomic and microscopic; characteristic of disease
Epidemiology
Study of disease in populations (i.e. causes, distributions, control). Considers health indicators, life expectancy, infant mortality.
Incidence vs. prevalence
Incidence: number of new cases in the population over a time period
Prevalence: total number of cases (new and existing) in the population
PDL1 Testing
PDL1 on cell membranes blocks tumour’s immune reaction.
Inhibitors can block PDL1, which stimulates immune system to attack
Cancers have a lot of PDL1 (so the tumor survives)
