Introduction to Pathology PDF

# Introduction to Pathology ## URS Vision The leading University in human resource development, knowledge and technology generation and environmental stewardship. ## URS Mission The University of Rizal System is committed to nurture and produce upright and competent graduates and empowered communi...

# Introduction to Pathology ## URS Vision The leading University in human resource development, knowledge and technology generation and environmental stewardship. ## URS Mission The University of Rizal System is committed to nurture and produce upright and competent graduates and empowered community through relevant and sustainable higher professional and technical instruction, research, extension and production services. ## URS Core Values - Responsiveness - Integrity - Service - Excellence - Social Responsibility ## URS Quality Policy The University of Rizal System commits to deliver excellent products and services to ensure total stakeholders' satisfaction in instruction, research, extension, production and dynamic administrative support and to continuously improve its Quality Management System processes to satisfy all applicable requirements. ## Grading System ### Lecture - 60% - class standing - 30% - quizzes - 20% - recitation - 10% - project ### Major Examinations - 40% **TOTAL: 100%** ## House Rules - 30 minutes grace period - Attendance is a must - Put your phones on silent mode - Wear your daily uniform ## Requirements - 1 ¼ index card white - name: (LAST NAME, GIVEN NAME, MIDDLE NAME) - Year and Program - Complete address - Birthday - Contact number - 1x1 clear picture (upper right) ## Learning Outcome At the end of this lecture course, the students should be able to: 1. Understand and define the concept and nature of pathology. 2. Identify and outline the mechanism and nature of diseases. 3. Relate and discuss the causes and effects of diseases. 4. Understand and outline the nature between the relationship of cell cycle and carcinogenesis. 5. Understand and apply disease prevention and promotion of good health. ## What is Pathology? Greek Origin: The word "pathology" comes from two Greek words: pathos (meaning suffering or disease) and logos (meaning study or discourse). - Pathology is the branch of medicine that focuses on the study of disease, its causes, mechanisms, and effects on the body. It involves examining tissue, blood, and other bodily fluids to understand disease processes. - The study of diseases, their causes, mechanisms, effects, and processes. It aims to understand the nature of diseases and how they affect the body. - looks at the structural and functional changes that diseases cause at the cellular, tissue, and organ levels. ## Importance of Pathology It provides critical insights into: ### Diagnosis Pathologists analyze biological samples (tissues, blood, fluids) to identify the presence of disease. They play a critical role in diagnosing conditions such as infections, cancer, and autoimmune diseases. ### Prognosis Pathology provides prognostic information by assessing the severity of the disease and predicting its future course. For instance, cancer staging and grading guide the management of cancer patients. ### Treatment Decisions The information derived from pathology studies helps doctors choose the appropriate treatments, such as surgery, chemotherapy, or targeted therapies. ### Prevention and Screening Pathologists are involved in developing screening techniques (e.g., detect diseases early, thus improving patient outcomes. ## Divisions of Pathology ### Anatomical Pathology - Involves the study of tissue samples to examine structural changes due to disease (e.g., biopsy, autopsy). #### Sub-specialities - Histopathology - Cytopathology - Forensic Pathology ### Clinical pathology - Focuses on laboratory medicine and diagnostic tests related to blood, urine, and other bodily fluids. #### Sub-specialties - Hematology - Microbiology - Biochemistry - Molecular Diagnostics ### Other Branches - Forensic Pathology: The study of causes of death, often in legal contexts. - Veterinary Pathology: Pathology related to animal diseases. - Research Pathology: Investigating new disease mechanisms, therapies, and biomarkers. ## Understanding Disease Mechanisms ### Pathogenesis Refers to the process by which a disease develops and progresses in the body. It encompasses the chain of events from the initial causative agent (e.g., pathogen, mutation) to the manifestation of symptoms. ### Key Factors - Genetic Factors: Mutations in DNA or inherited genetic conditions. - Environmental Factors: Exposure to toxins, pathogens, or trauma. - Immunological Factors: Immune system dysfunction or response to infection. - Cellular Injury: Disruptions in cell function, leading to disease. ## Key Processes in Pathology 1. Inflammation: - A protective response to injury or infection that can become chronic and contribute to disease. 2. Cell Death: - Apoptosis (programmed cell death) and necrosis (uncontrolled cell death) are both key processes in various diseases. 3. Neoplasia: - Formation of new abnormal cells. - Abnormal growth of cells, leading to benign or malignant tumors (e.g., cancer). 4. Infection: - Pathogens (bacteria, viruses, fungi, parasites) invade the body, causing diseases. 5. Immunopathology: - Diseases caused by the immune system attacking the body's own tissues, such as autoimmune diseases. ## The Pathologist's Role in Medicine ### Clinical Pathologists - They focus on laboratory tests and the interpretation of results to assist in diagnosing diseases. They often work with patient samples (blood, urine, etc.) in hospitals or diagnostic laboratories. ### Anatomical Pathologists - These pathologists examine tissues and organs, often through biopsies or autopsies, to identify diseases, particularly cancers. ### Forensic Pathologists - Forensic pathologists perform autopsies to determine the cause of death in cases where foul play or unusual circumstances are suspected. ### Research Pathologists - These professionals focus on the molecular and cellular mechanisms underlying diseases, contributing to new treatments and diagnostic techniques. ## How Pathology Contributes to Medical Practice ### Diagnosis Pathologists help identify the causes of symptoms through examination of tissues and fluids, such as detecting infections, cancers, and genetic conditions. ### Prognosis By studying the severity and progression of diseases, pathologists help predict outcomes, such as determining the stage of cancer or the severity of infection. ### Therapeutic Decisions Pathology informs the choice of treatment, especially in oncology (e.g., choosing chemotherapy regimens based on cancer type and stage). ### Prevention and Early Detection Pathologists contribute to screening programs, allowing early detection of diseases like cancer, which leads to better treatment success rates. ## Cellular Adaptations and Subcellular Alterations ### Cellular Adaptations Are reversible changes in the structure or function of cells in response to various environmental stimuli or stressors. These adaptations help cells survive under adverse conditions. ### Subcellular Alterations Involve changes at the organelle or molecular level, usually occurring as a result of pathological stimuli. These alterations can be either reversible or irreversible and affect cellular function. ## Types of Cellular Adaptations 1. Hypertrophy: - Increase in cell size due to increased functional demand (e.g., muscle cells in athletes). 2. Atrophy: - Decrease in cell size due to reduced functional demand or loss of stimuli (e.g., muscle wasting in immobility or neurodegenerative diseases). 3. Hyperplasia: - Increase in cell number due to increased cellular proliferation, usually in response to stimuli (e.g., benign prostatic hyperplasia). 4. Metaplasia: - Reversible change where one differentiated cell type is replaced by another type, often in response to chronic irritation (e.g., squamous metaplasia in the respiratory epithelium due to smoking). 5. Dysplasia: - Abnormal development of cells, often pre-cancerous, characterized by changes in size, shape, and organization. - Presence of abnormal cells within the tissue; not a cancer but may become cancer. ## Subcellular Alterations Involve changes in organelles or intracellular structures that can affect cell function. These changes can be reversible or irreversible depending on the severity of the insult. ### Key Types of Subcellular Alterations 1. Mitochondrial Alterations: - Mitochondrial swelling, dysfunction, and release of pro-apoptotic factors (e.g., cytochrome c). - **Clinical Significance:** Mitochondrial dysfunction is implicated in many diseases, including neurodegenerative diseases, cardiovascular diseases, and aging. 2. Endoplasmic Reticulum Stress: - Activation of the unfolded protein response (UPR) in response to the accumulation of misfolded proteins. - **Clinical Significance:** ER stress is implicated in a variety of diseases, including diabetes (due to insulin resistance) and neurodegenerative diseases (due to protein aggregation). 3. Lysosomal Changes: - Lysosomal enlargement and altered enzymatic activity in response to cellular damage (e.g., in neurodegenerative diseases). - **Clinical Significance:** Lysosomal storage diseases (e.g., Tay-Sachs disease, Gaucher disease) are caused by defects in lysosomal enzymes, leading to the accumulation of undigested materials in the cell. ## Next Week - QUIZ