Pathology: Disease Mechanisms and Processes

Definition and Scope

• General pathology is the study of the underlying mechanisms and processes of diseases, focusing on the cellular and molecular changes that occur in response to injury or disease.
• It encompasses the study of the causes, mechanisms, and consequences of disease, as well as the structural and functional changes that occur in tissues and organs.

Types of Diseases

• Infectious diseases: caused by microorganisms such as bacteria, viruses, fungi, and parasites.
• Non-infectious diseases: caused by genetic mutations, environmental factors, and other non-infectious factors.
• Neoplastic diseases: characterized by abnormal cell growth and tumor formation.
• Degenerative diseases: caused by progressive damage or deterioration of cells and tissues.

Cellular Responses to Injury

• Inflammation: a response to tissue damage, characterized by increased blood flow, swelling, and infiltration of immune cells.
• Repair: the process of restoring tissue structure and function after injury.
• Adaptation: changes in cell structure and function in response to chronic injury or stress.

Cellular Changes in Disease

• Hypertrophy: an increase in the size of cells in response to increased demand or stress.
• Hyperplasia: an increase in the number of cells in response to increased demand or stress.
• Atrophy: a decrease in the size of cells due to decreased demand or stress.
• Metaplasia: a change in cell type in response to chronic injury or stress.

Tissue Responses to Injury

• Fibrosis: the formation of scar tissue in response to chronic injury or inflammation.
• Cirrhosis: a type of fibrosis that occurs in the liver.
• Calcification: the deposition of calcium salts in tissues, often in response to injury or disease.

Systemic Diseases

• Autoimmune diseases: characterized by an immune response against the body's own tissues.
• Immunodeficiency diseases: characterized by a weakened immune system.
• Endocrine diseases: characterized by disorders of hormone production or function.

Laboratory Diagnosis

• Microscopy: the examination of tissues and cells using a microscope.
• Biochemistry: the analysis of biochemical markers and enzymes in bodily fluids.
• Molecular diagnostics: the use of molecular techniques such as PCR and DNA sequencing to diagnose diseases.

General Pathology

• Focuses on cellular and molecular changes in response to injury or disease
• Encompasses the study of causes, mechanisms, and consequences of disease

Types of Diseases

• Infectious diseases: caused by microorganisms (bacteria, viruses, fungi, parasites)
• Non-infectious diseases: caused by genetic mutations, environmental factors, and other non-infectious factors
• Neoplastic diseases: characterized by abnormal cell growth and tumor formation
• Degenerative diseases: caused by progressive damage or deterioration of cells and tissues

Cellular Responses to Injury

• Inflammation: response to tissue damage, characterized by increased blood flow, swelling, and immune cell infiltration
• Repair: process of restoring tissue structure and function after injury
• Adaptation: changes in cell structure and function in response to chronic injury or stress

Cellular Changes in Disease

• Hypertrophy: increase in cell size due to increased demand or stress
• Hyperplasia: increase in cell number due to increased demand or stress
• Atrophy: decrease in cell size due to decreased demand or stress
• Metaplasia: change in cell type in response to chronic injury or stress

Tissue Responses to Injury

• Fibrosis: formation of scar tissue in response to chronic injury or inflammation
• Cirrhosis: type of fibrosis that occurs in the liver
• Calcification: deposition of calcium salts in tissues, often in response to injury or disease

Systemic Diseases

• Autoimmune diseases: characterized by immune response against the body's own tissues
• Immunodeficiency diseases: characterized by a weakened immune system
• Endocrine diseases: characterized by disorders of hormone production or function

Laboratory Diagnosis

• Microscopy: examination of tissues and cells using a microscope
• Biochemistry: analysis of biochemical markers and enzymes in bodily fluids
• Molecular diagnostics: use of molecular techniques (PCR, DNA sequencing) to diagnose diseases