Introduction To Disease PDF

Created by Turbolearn AI Introduction to Disease Defining Health and Disease ‍ The World Health Organization (WHO) defines health as: The state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity. This means all body systems are functi...

Created by Turbolearn AI Introduction to Disease Defining Health and Disease ‍ The World Health Organization (WHO) defines health as: The state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity. This means all body systems are functioning normally and in balance. Homeostasis is the term for this state of dynamic equilibrium. It's maintained by continuous feedback and regulation in response to internal and external changes. Characteristics of Disease Signs: Objective physical manifestations (e.g., swelling, redness). Symptoms: Subjective manifestations (e.g., pain, weakness). Pathology: The study of disease. Pathologist: A physician specializing in diagnosing diseases by studying cell and tissue morphology. Clinician: The physician or healthcare professional who cares for patients. Disorders and Syndromes A disorder is an abnormal condition of the mind or body, a combination of symptoms, physical findings, or lab results linked by a common factor (genetic, biochemical, physiological, or structural abnormality). Syndromes are examples of disorders; one example is Down syndrome (trisomy 21). Medical Imaging Techniques The following table summarizes various medical imaging techniques: Page 1  Created by Turbolearn AI Technique Description Advantages Disadvantages Uses X-rays to image the chest. Denser tissues (like Relatively Limited soft tissue Chest X-rays ribs) appear white; less inexpensive and detail. dense tissues (like lungs) readily available. appear black. X-ray technology used to Can be screen for breast cancer; Early detection of uncomfortable; Mammography often detects lumps before breast cancer. some radiation they're palpable. exposure. Detailed cross- Uses multiple X-ray sectional images Higher radiation images from different CT Scan for diagnostic and exposure than X- angles, integrated into a therapeutic rays. 3D picture by a computer. purposes. Uses radiofrequency energy emitted by More expensive and Magnetic hydrogen atoms in a Excellent soft time-consuming; Resonance magnetic field to create tissue detail; no can induce Imaging (MRI) images. High water and fat ionizing radiation. claustrophobia. content tissues are well visualized. Uses high-frequency Non-invasive; no Image quality can sound waves to create ionizing radiation; be operator- Ultrasound images based on tissue relatively dependent; limited density differences. inexpensive. penetration depth. Uses a positron-emitting Detects radionuclide attached to a metabolically Uses ionizing PET Scan biologically active active tissues, radiation; expensive. molecule to image such as cancer metabolic activity. cells. Cytology 細胞 Cytology is the study of cells. Examination of cells can distinguish between benign and cancerous (malignant) cells. Cancer cells often display characteristics such as: enlarged, active nucleus; minimal cytoplasm; crowding; and cells appearing stuck together. Page 2  Created by Turbolearn AI Fine Needle Aspiration (FNA) The goal of Fine Needle Aspiration (FNA) is to obtain cells from a suspicious lesion and send them to a lab for microscopic examination to establish a diagnosis. Example: An FNA of a thyroid adenomatous nodule shows homogeneous, small, round, and dark nuclei—indicating a benign nodule. This is in contrast to the active- looking nuclei of cervical cancer cells. The Course of Disease Acute: Short-term illness. Terminal: Illness leading to death. Chronic: Long-term illness. Remission: Period where disease symptoms lessen or disappear. Exacerbation: Increase in severity of a disease. Relapse: Recurrence of a disease after remission. Complication: A new problem arising from an existing disease. Sequela: A condition that is the consequence of a previous disease or injury. Describing the Occurrence of Disease Mortality: Number of deaths. Morbidity: Incidence of disease (how many people are affected). Incidence: Number of newly diagnosed cases. Prevalence: Percentage of a population affected by a disease at a given time. Epidemiology: Study of the occurrence, transmission, distribution, and control of disease. Etiology: Cause of a disease. Pathogenesis: How a disease's cause leads to bodily changes resulting in the disease. Idiopathic: Disease with no recognizable cause; seemingly spontaneous. Page 3  Created by Turbolearn AI Chief Causes of Disease (Etiology) Cause Description Example Category Passed down through genes from parents Hereditary Sickle cell anemia to offspring. Present at birth; birth defects acquired Congenital during fetal development or from parents' Cleft lip/palate genetic makeup. Continuous process of degenerative cell Degenerative changes, leading to tissue or organ Osteoarthritis deterioration over time. Chronic sinusitis, Uncontrolled inflammation causing healthy Inflammatory asthma, contact tissue destruction. dermatitis Systemic Lupus Autoimmune Immune system attacks healthy cells. Erythematosus (SLE) Neoplastic Abnormal growth (malignant or benign). Cancer Genetically determined or acquired; body's Type 1 diabetes mellitus Metabolic process of obtaining/making energy from (T1DM) food. Physical injury or wound from external Chronic traumatic Traumatic force. encephalopathy (CTE) Nutritional Deficiency or excess of nutrients Scurvy, obesity Page 4