Topic 1B- Introduction to Pathology- Cause of Disease and General Basis of Pathologic Condition

RT 218 Topic 1B or Topic 2

Pathology

The study of disease processes

Purpose of medical imaging

To demonstrate the presence or absence of disease

Disease

Any abnormal change or disturbance in the function or structure within the body as a result of some type of injury

Pathogenesis

The sequence of events producing cellular changes that ultimately lead to observable changes known as manifestations

Manifestations

Observable changes resulting from pathogenesis

Symptom

The patient’s subjective perception of the disease, such as a headache or abdominal pain

Sign

Objective manifestations detectable with examination, such as a rash, fever, swelling, or a mass

Syndrome

A group of signs and symptoms that characterize a specific abnormal disturbance

Etiology

The study of the cause of a disease

Common agents that cause diseases

Viruses, bacteria, trauma, heat, chemical agents, and poor nutrition

Nosocomial

A hospital-acquired infection or disease

Idiopathic

A disease with no causative factor or without an identifiable cause

Iatrogenic

Adverse responses to medical treatment itself

Acute

Diseases that usually have a quick onset and last for a short period, such as pneumonia

Chronic

Diseases that manifest more slowly and last for a very long time, such as multiple sclerosis

Sequelae

A condition caused by a previous disease, injury, therapy, or other trauma

Diagnosis

The identification of a disease an individual is believed to have

Prognosis

The prediction of the course of a disease and the prospects for the patient's recovery

Morphology

The structure of cells or tissue

Destructive (Lytic/Subtractive) processes

Pathologic processes that reduce body or organ mass, requiring a decrease in kVp exposure factors

Additive (Sclerotic) processes

Pathologic processes that add to body tissue, requiring an increase in kVp exposure factors

Epidemiology

The investigation of disease in large groups

Prevalence

The number of cases found in a given population

Incidence

The number of new cases found in a given time

Endemic

A disease of high prevalence in an area where a causative organism is commonly found

Morbidity rate

The incidence of sickness that interferes with daily routine

Mortality rate

The average number of deaths caused by a particular disease in a population

Genetic causes of cell injury

Developmental defects (morphogenesis errors), cytogenetic (karyotypic) defects like chromosomal abnormalities, single-gene defects, and multifactorial inheritance disorders

Acquired causes of cell injury

Hypoxia and ischemia, physical agents, chemical agents, microbial agents, immunologic agents, nutritional derangements, aging, psychogenic diseases, iatrogenic factors, and idiopathic diseases

Atrophy

A decrease in cell size

Hypertrophy

An increase in cell size

Hyperplasia

An increase in the number of cells in a tissue as a result of excessive proliferation

Anaplasia

The absence of tumor cell differentiation and loss of cellular organization

Dysplasia

Abnormal changes of mature cells, also known as atypical hyperplasia

Metaplasia

The conversion of one cell type into another cell type that is not normal for that tissue

Structural disease

Disease involving an alteration in the structure of an organ or system

Functional disease

Disease involving an alteration in the function of an organ or system

Congenital

Diseases present at birth resulting from genetic or environmental factors, including those acquired in utero like Down Syndrome

Hereditary

Diseases caused by developmental disorders genetically transmitted from parents to children through gene abnormalities, such as Hemophilia

Dominant inheritance

A disease transmitted by a single gene from either parent

Recessive inheritance

A disease transmitted by both parents to an offspring

Inflammatory disease

Disease resulting from the body’s reaction to a localized injurious agent

Infective inflammatory disease

Inflammation resulting from invasion by microorganisms like viruses, bacteria, or fungi

Toxic inflammatory disease

Inflammation caused by poisoning by biologic substances

Allergic diseases

An overreaction of the body’s own defenses

Autoimmune disorders

Diseases in which the body forms autoantibodies that injure the patient’s own tissues, such as Rheumatoid Arthritis or HIV/AIDS

Acute inflammation cardinal signs

Heat (Calor), redness (Rubor), swelling (Tumor), pain (Dolor), and loss of function (Functio Laesa)

Treatments of inflammation

Tissue regeneration, repair by fibrous connective tissue (scarring), debridement, and remodeling

Infection

An inflammatory process caused by a disease-causing organism

Virulence

The ease with which an organism can overcome body defenses

Degenerative disease

Diseases caused by a deterioration of the body, often following trauma or aging

Factors affecting the rate of aging

Heredity, diet, and environmental factors

Diseases associated with aging

Atherosclerosis, osteoporosis, and osteoarthritis

Metabolic disease

Disease caused by the disturbance of the normal physiologic physical and chemical processes of the body

Endocrine disorders

Metabolic disturbances such as Diabetes Mellitus or Hyperparathyroidism

Dehydration

The most common disturbance of fluid balance, caused by insufficient intake or excessive loss of water

Homeostasis

The body’s normal internal resting state

Traumatic diseases

Disorders resulting from mechanical forces, ionizing radiation, or extreme temperatures, such as fractures, burns, and frostbite

Neoplastic disease

Disease resulting in new, abnormal tissue growth

Proliferation

Cell division

Differentiation

The process of cellular specialization from generic embryonic cells into specific types like cardiac or nerve cells

Lesion

Cellular changes in response to disease

Benign Neoplasm

A localized, non-invasive growth composed of well-differentiated cells with uncontrolled growth

Malignant Neoplasm

A growth that exhibits loss of control over cell proliferation and differentiation, tends to spread, and invades other tissues

Metastasis

The spread of malignant cancer cells resulting in a secondary tumor distant from the primary lesion

Hematogenous spread

The spread of cancer cells via blood vessels

Lymphatic spread

The spread of cancer cells via the lymphatic system

Invasion

The spread of cancerous cells into surrounding tissue due to proximity

Seeding

The travel of cancerous cells to a distant site or distant organ system

Cancer

A general term used to denote various types of malignant neoplasm

Carcinoma

A type of cancer derived from epithelial tissue, such as adenocarcinoma

Sarcoma

A type of cancer arising from connective tissue, such as fibrosarcoma

Lymphoma

A type of cancer arising from lymphatic cells

TNM system

A cancer staging system emerged in the 1950s where T stands for Tumor size, N for lymph Node involvement, and M for Metastases

Stage 0 Cancer

Indicates no cancer is present, only abnormal cells with the potential to become cancer

Stage I Cancer

Indicates the cancer is small and localized in one area

Stage II and III Cancer

Indicates the cancer is larger and has grown into nearby tissues or lymph nodes

Stage IV Cancer

Indicates the cancer has spread to other parts of the body