Pathophysiology Complications of Pregnancy, Lecture Notes

Pathophysiology (1) (MBS 213) week 7: Potential Complications of Pregnancy Textbook; Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 9, P. 167-175 Significant Physiologic Changes During Pregnancy Weight Gain and Nutrition: - Typical weight gain is 11-14 kg (25-3...

Pathophysiology (1) (MBS 213) week 7: Potential Complications of Pregnancy Textbook; Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 9, P. 167-175 Significant Physiologic Changes During Pregnancy Weight Gain and Nutrition: - Typical weight gain is 11-14 kg (25-30 lb), mostly in the last trimester, due to the uterus, placenta, amniotic fluid, fetus, and increased blood volume. - Higher demand for protein, fats, carbohydrates, vitamins, and minerals, with excess calories stored as fat. - The fetus stores iron in the last trimester for post-birth needs, and adequate calcium supports fetal bones and teeth. - Changes in salivary secretions can increase dental caries risk, making oral hygiene and dental checkups essential. Musculoskeletal Changes: - Pelvic joints loosen, causing a waddling gait and reduced stability. Increased abdominal weight shifts the center of gravity, leading to lordosis and backache. Regular moderate exercise helps maintain posture and cardiovascular health. Significant Physiologic Changes During Pregnancy Digestive System Changes During Pregnancy: 1-Nausea and Vomiting: - Common in the first trimester due to hormonal changes. -Managed by frequent small meals, avoiding fatty/spicy foods, and reducing fluid intake during meals. Severe cases (hyperemesis gravidarum) may require hospitalization to restore fluids and electrolytes. 2-Digestive Motility and Discomfort: - Progesterone relaxes smooth muscles, slowing stomach emptying and causing bloating, heartburn, and abdominal discomfort. - Pressure from the growing uterus further affects digestion. 3-Constipation and Hemorrhoids: - Slower gastric motility and iron supplements often cause constipation. - Chronic constipation may lead to painful, bleeding hemorrhoids. - A high-fiber diet helps prevent constipation and straining during bowel movements. Potential Complications Of Pregnancy Ectopic Pregnancy (Tubal Pregnancy) Definition: Fertilized ovum implants outside the uterus, usually in the fallopian tube. Causes: Often linked to pelvic inflammatory disease (PID), which can scar the fallopian tube. Complications: - Spontaneous abortion may occur. - Continued growth may rupture the tube, causing severe hemorrhage or peritonitis. Symptoms: Severe pelvic or abdominal pain due to blood irritating the peritoneal membranes. Treatment: - Medical emergency requiring prompt surgical removal of the embryo and affected tube. - Tubal pregnancy cannot be carried to viability. Gestational Diabetes Mellitus (GDM) - Definition: Increased glucose intolerance during pregnancy, affecting 2-5% of women. - Risk Factors: Family history of diabetes or previous high birth weight infants. - Complications: Elevated blood and urine glucose levels. Higher risk of fetal abnormalities if glucose is high in the first trimester. Increased likelihood of stillbirth. Newborns are typically larger and may have difficulty regulating blood glucose after birth. - Management: Dietary control is essential. Insulin may be needed; oral hypoglycemics are avoided due to teratogenic risks. - Prognosis: Condition may resolve after pregnancy, but affected women have a higher risk of developing diabetes later in life. Placental Problems 1. Placenta Previa: - Placenta implants in the lower uterus or over the cervical os. - Bleeding occurs when the uterus expands and contracts near the end of pregnancy. - Key Sign: Bright red, painless bleeding. - Diagnosed via ultrasound. - Hemorrhage risks both mother and fetus, requiring urgent care. 2. Abruptio Placentae: - Premature separation of the placenta from the uterine wall. - Bleeding may be internal or external, with dark red blood. - Key Sign: Abdominal pain is common. - More frequent in the last trimester. Pathophysiology (1) (MBS 213) week 6: Disorders disease associated with adolescence Textbook; Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 8, P. 157-166 Adolescence: A Period of Major Changes Definition & Duration: Transition from childhood to adulthood (ages 10-18), marked by physical, hormonal, and social changes. Puberty & Hormonal Changes: Hypothalamus and pituitary trigger hormone production— estrogen & progesterone (females), testosterone (males)—leading to reproductive maturity. Growth & Development: Rapid height increase (earlier in females, longer in males).Skeletal changes: broader pelvis (females), wider shoulders & muscle growth (males).Growth occurs in stages, causing temporary awkwardness. Nutritional Needs: High demand for calcium, vitamin D, iron, and protein to support bone & muscle growth; poor diet may increase osteoporosis risk. Cardiovascular & Metabolic Changes: Increased blood volume & cardiac strength; basal metabolic rate declines to adult levels. Health Risks: Poor nutrition, fatigue from growth mismatches, and steroid abuse for muscle enhancement. Adolescent Obesity – Causes & Consequences Causes: -Reduced fat-burning after puberty. -Poor diet (high-fat, high-carb foods) & low physical activity. Health Risks: -Increases risk of Type 2 diabetes, heart disease, high blood pressure, & joint damage. -Psychological issues more common in obese teens. Rising Trends: -Obesity rates tripled since 1980. -More teens now have diabetes & heart conditions. Prevention: -Healthy diet (fewer processed snacks, more nutritious meals). -More exercise, less screen time. Metabolic Syndrome & Long-Term Impact Definition: A cluster of conditions increasing the risk of heart disease & diabetes. Key Signs: Excess belly fat (increased waist size). Insulin resistance (blood sugar & fat metabolism issues). High blood pressure & heart problems. Serious Health Outcomes: 49% of obese youth develop metabolic syndrome. Leads to early-onset heart disease, diabetes, and shorter life expectancy. Prevention: Weight loss significantly reduces risks. Encouraging healthy lifestyle choices is crucial. Eating Disorders: Anorexia & Bulimia - Common in adolescent & young adult females in Western cultures. - Driven by body image concerns & psychological factors. - Can cause severe malnutrition, growth issues, and life-threatening complications. Anorexia Nervosa: - Self-starvation → extreme weight loss & malnutrition. - Symptoms: Amenorrhea, brittle nails, low body temp, cardiac risks (arrhythmias, arrest). - Risks: Electrolyte imbalances, osteoporosis, organ failure. - Treatment: Hospitalization, behavioral therapy, nutrition support. Bulimia Nervosa: - Binge eating (carbs) followed by purging (vomiting, laxatives, excessive exercise). - Maintains normal weight but leads to nutrient deficiencies, menstrual issues. - Complications: Tooth enamel erosion, esophagitis, electrolyte imbalances, cardiac risks. - Treatment: Therapy, nutritional guidance, addressing psychological factors. Skin Disorders: Acne Vulgaris Common in Adolescents: Particularly in males, acne affects the sebaceous glands and hair follicles on the face, neck, and upper trunk. Types of Lesions: -Comedones (whiteheads/blackheads): Non-inflammatory, clog pores with sebum and cells. - Inflammatory Lesions: Infection caused by Propionibacterium acnes, leading to pustules, tissue damage, and scarring. Predisposing Factors: Genetics, hormonal changes, oily cosmetics, heavy clothing, and environmental conditions. Treatment: -Prevention: Regular cleaning, improved nutrition, avoiding oil-based products. -Medications: Benzoyl peroxide, tretinoin, isotretinoin, and antibiotics. -Scar treatment: Dermabrasion. C-Menstrual Abnormalities Delayed menarche, or primary amenorrhea, is defined as the absence of menstruation after the age of 17. It is typically caused by abnormalities in the reproductive organs (either structural or hormonal), the pituitary gland, or the hypothalamus. Additionally, consistent strenuous physical activity, such as training for competitive sports, and certain systemic disorders, such as hypothyroidism or diabetes, may also delay menarche. Dysmenorrhea refers to discomfort of varying severity during the first or second day of menstruation. In some cases, the pain can be incapacitating, accompanied by vomiting or fainting. This cramping pain results from increased uterine prostaglandin secretion, which enhances muscle contractility, irritates nerve endings, and contributes to vascular changes and ischemia in the uterine wall as the endometrium is shed. Treatment for dysmenorrhea includes hormonal therapy or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil). Pathophysiology (1) (MBS 213) week 5: Fluid, Electrolyte, and Acid Base Imbalances Textbook; Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 6, P. 117142 Fluid Balance Water is essential for metabolism, nutrient transport, and waste removal. The body has two main fluid compartments: Intracellular Fluid (ICF) – inside cells. Extracellular Fluid (ECF)– includes blood, interstitial fluid, cerebrospinal fluid, and secretions. -Water moves between compartments by filtration and osmosis, regulated by hydrostatic (push) and osmotic (pull) pressures. -Water is gained from food, drinks, and metabolism and lost through urine, feces, sweat, and breathing. Fluid balance is controlled by: Thirst mechanism (brain detects need for water).  ADH (Antidiuretic Hormone) – reduces urine output. Aldosterone – retains sodium and water.  ANP (Atrial Natriuretic Peptide) – promotes fluid loss to lower blood pressure.  Fluid Imbalance Imbalances can lead to edema (fluid retention) or dehydration (fluid loss). Fluid Excess (Edema) Dehydration Edema is excess fluid in the interstitial Dehydration refers to insufficient body fluid resulting either from space, causing swelling. inadequate intake or excessive It can be localized (e.g., face) or loss of fluids or a combination of generalized (throughout the body). the two. Gravity-dependent areas (e.g., feet, It primarily affects the ankles) are more affected. extracellular compartment and can progress to cellular fluid loss, Prolonged edema disrupts circulation and impairing function. cell function. Causes of Edema Cause example 1- Increased Capillary Hydrostatic Pressure: Causes fluid to Hypertension, heart be pushed out of capillaries into tissues. failure, kidney disease. 2- Decreased Plasma Oncotic Pressure: Reduced plasma Liver disease, proteins (especially albumin) cause fluid to remain in tissues. malnutrition, nephrotic syndrome. 3- Lymphatic Obstruction: Lymph vessels fail to drain excess Tumors, infections fluid, leading to accumulation. (elephantiasis), surgical removal of lymph nodes. 4- Increased Capillary Permeability: Leaky capillaries allow Inflammation, allergic proteins and fluid to escape into tissues. reactions, burns, sepsis. Dehydration Severity Levels (based on body weight loss): o Mild: 2% loss o Moderate: 5% loss o Severe: 8% loss Common causes: o Vomiting, diarrhea, excessive sweating o Diabetic ketoacidosis o Insufficient intake (elderly, unconscious) o Over-concentrated infant formula Dehydration Effects: o Dry mouth, decreased skin elasticity o Low blood pressure, weak pulse, fatigue o Mental confusion due to brain cell dehydration High-risk groups: Infants and elderly due to low fluid reserves. Body Compensation: o Increased thirst & heart rate o Vasoconstriction (pale, cool skin) o Reduced urine output (concentrated urine)  Sodium Imbalance 1. Role of Sodium (Na⁺) o Main extracellular cation, regulated by aldosterone. o Maintains fluid balance, nerve function, and muscle contraction. o Lost through sweat, urine, feces; obtained from food and drinks. 2. Hyponatremia (Low Sodium 145 mEq/L) o Causes: Excess sodium intake, dehydration, diabetes insipidus, loss of thirst mechanism, watery diarrhea, rapid breathing. o Effects: Weakness, agitation, dry skin & mucous membranes, increased thirst, low urine output. Acid Base Balance pH Scale: Measures acidity or alkalinity. Normal blood pH is 7.35-7.45. Buffers: Substances that help maintain pH balance by neutralizing acids or bases. Organs Involved: Lungs (regulate CO2) and kidneys (regulate bicarbonate, HCO3). Acidosis: Excess acid production or reduced acid excretion. Alkalosis: Excess base production or reduced base excretion. Compensation Mechanisms Lungs: Adjust breathing rate to regulate CO2 levels. Kidneys: Adjust bicarbonate reabsorption or excretion to maintain pH balance. Pathophysiology (1) (MBS 213) week 4: Neoplasm Textbook ;Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 5, P. 95-115  Benign And Malignant Tumors A neoplasm or tumor is a cellular growth that is no longer responding to normal body controls. The cells continue to reproduce when there is no need for them. This excessive growth deprives other cells of nutrients. Many neoplasms are unable to function as normal tissue cells because they consist of atypical (abnormal) or immature cells. The characteristics of each tumor depend on the specific type of cell from which the tumor arises, resulting in a unique appearance and growth pattern. The expanding mass creates pressure on surrounding structures.  Warning Signs Of Cancer 1. Unusual bleeding or discharge anywhere in the body. 2. Change in bowel or bladder habits (e.g., prolonged diarrhea or discomfort). 3. A change in a wart or mole (i.e., color, size, or shape). 4. A sore that does not heal (on the skin or in the mouth, anywhere). 5. Unexplained weight loss. 6. Anemia or low hemoglobin, and persistent fatigue. 7. Persistent cough or hoarseness without reason. 8. A solid lump, often painless, in the breast or testes or anywhere on the body.  Spread of Malignant Tumors There are three basic mechanisms for the spread of cancer: 1. Invasion refers to local spread, in which the tumor cells grow into adjacent tissue and destroy normal cells. 2. Metastasis means spread to distant sites by blood or lymphatic channels. In this case the tumor cells erode into a vein or lymphatic vessel, travel through the body, and eventually lodge in a hospitable environment to reproduce and create one or more secondary tumors. 3. Seeding refers to the spread of cancer cells in body fluids or along membranes, usually in body cavities, the tumor cells break away and travel easily with the movement of fluid and tissue. An example is ovarian cancer, in which the large peritoneal membrane encourages dispersion of the tumor cells throughout the peritoneal cavity  Treatment Basic treatment measures may involve any (or all) of depending on specific cancer; Surgery (solid tumors) Chemotherapy (hematopoietic cancers such as leukemia because the cancer cells are dispersed in the blood) Radiation Immunotherapy stimulates the patient's immune system to attack the cancer Combination Treatment may be; Curative if the tumor is small and localized, or Palliative if the cancer is advanced, to reduce the manifestations and complications  Examples Of Malignant Tumors - Skin Cancer Skin Cancer is usually visible and treatable, mostly with surgery, and has a slow progression. Most types, except malignant melanoma, have an excellent prognosis. They often recur, mainly on sun-exposed areas like the head, neck, and back. It's more common in fair-skinned individuals over 40 in southern climates. Reducing sun exposure can help prevent skin cancer. Basal Cell Carcinoma: -Most common form. -Appears as a pearly papule with a central ulcer ("rodent ulcer"). -Lacks pain or itching and grows slowly. -Invades subcutaneous tissues.  Examples Of Malignant Tumors - Ovarian Cancer Ovarian Cancer has a high mortality rate and poor prognosis because it is often hidden and asymptomatic until advanced stages. Location: Tumor hidden in the peritoneal cavity, making early detection difficult. Risk Factors: Hormonal and genetic factors. Symptoms: Vague symptoms appear when the tumor is large and causes pressure on adjacent structures (e.g., bladder, intestine). Tumor Markers: CA125 can help in early diagnosis and treatment monitoring but has limitations. Spread: Tumor spreads easily through lymphatic vessels and seeding in the peritoneal cavity, affecting the liver, uterus, and pelvis.  Malnutrition in Advanced Cancer Patients Management Strategies: Comfort Measures: Ice and mouth rinses to alleviate mouth ulcers and inflammation. Diet Adjustments: Frequent small meals with favorite, non-irritating foods. Medications: Pain control and antiemetic drugs to stimulate appetite. Nutritional Support: Total parenteral nutrition (TPN) for direct nutrient administration. Addressing these issues can significantly improve the patient's nutritional status and overall well-being. Pathophysiology (1) (MBS 213) lecture 3: immunity and abnormal responses Textbook ;Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 3, P.39-67  Purpose of the immune system: The Immune System's Role: Protects the body from infections and diseases. Recognizes and attacks foreign invaders (like bacteria and viruses). Can also help identify and destroy abnormal cells, such as cancer cells. Key Features: Distinguishes "self" from "non-self": Identifies and attacks foreign substances while leaving healthy body cells alone. Memory: Remembers past encounters with invaders for faster responses in the future Regulation: Has built-in controls to prevent excessive or harmful reactions. Cancer and the Immune System: A strong immune system can help prevent cancer by recognizing and destroying abnormal cells. A weakened immune system can increase the risk of cancer development. However, some cancer cells can evade the immune system's detection.  Hypersensitivity Reactions Hypersensitivity or allergic reactions are unusual and perhaps damaging immune responses to normally harmless substances. These reactions stimulate an inflammatory response. There are four basic types of hypersensitivities, which differ in the mechanism causing tissue injury: Type I Hypersensitivity: Allergic Reactions Type II : Cytotoxic Hypersensitivity Type III: Immune Complex Hypersensitivity Type IV: Cell-mediated Or Delayed Hypersensitivity  Type I Hypersensitivity: Allergic Reactions This is an allergic reaction mediated by IgE antibodies. When first exposed to an allergen, the body produces IgE antibodies that attach to mast cells. Upon re-exposure, it binds to the IgE antibodies on mast cells, triggering the release of chemicals like histamine, leading to symptoms like: Redness, swelling, vesicles or blisters, Intense itching (pruritus) examples: Hay Fever (Allergic Rhinitis): Sneezing, runny nose, itchy eyes, and congestion. Often seasonal but can occur year-round due to various allergens. Food Allergies: Nausea, vomiting, diarrhea, and skin rashes (hives).Severe cases can cause airway obstruction. Atopic Dermatitis (Eczema):Chronic skin condition common in children. Itchy rashes on the face, trunk, and extremities. Often associated with food allergies, irritants, and dry skin. Asthma: Allergic reactions in the airways can trigger asthma, causing difficulty breathing. Often occurs in families with a history of hay fever and eczema.  Infection What is Infection? Infection occurs when the body is invaded and colonized by pathogenic microorganisms (bacteria, viruses, fungi, parasites). These microorganisms can disrupt normal bodily functions and cause a range of symptoms and diseases. Transmission: Direct Contact: Touching infected lesions, sexual intercourse. Indirect Contact: Contaminated objects (fomites), food, water. Droplet Transmission: Inhaling respiratory secretions. Aerosol Transmission: Inhaling airborne particles containing microorganisms. Vector-borne Transmission: Transmission through insects or animals. Reservoirs of Infection: Infected individuals (symptomatic or asymptomatic). Animals. Contaminated environments (water, soil, food). Nosocomial Infections: Infections acquired in healthcare settings (hospitals, clinics). Common causes: *Poor hand hygiene. *Contaminated equipment. *Weakened immune systems in patients. *Antibiotic-resistant bacteria (e.g., MRSA, C. difficile). Host Resistance: This refers to how well your body can fight off infections. Factors that weaken resistance: Age (very young or old), genetic factors, weakened immune system (like in HIV/AIDS), poor nutrition, chronic diseases, stress, injuries to the skin, and long-term use of certain medications like steroids. Pathophysiology (1) (MBS 213) Lecture 2 : inflammation and healing Textbook ;Pathophysiology for the Health Professions, 4th edition, 2011 Chapter 2, P.15- 37 Review of normal defenses in the body i. First Line of Defense - Mechanical Barriers: 1. Skin and Mucous Membranes: These act as physical barriers to prevent harmful agents from entering the body. 2. Body Secretions: Saliva and tears contain enzymes that help inactivate or destroy potential threats. ii. Second Line of Defense - Nonspecific Responses: 1. Phagocytosis: Neutrophils and macrophages engulf and destroy bacteria, cell debris, and foreign substances. 2. Inflammation: A process that aims to limit the effects of injury or harmful agents through a series of events involving increased blood flow and immune cell activation. 3. Interferons: Proteins that protect uninfected cells from viral infections. iii. Third Line of Defense - Specific Responses: 1. Immune System: Activated upon exposure to specific substances, leading to the creation of antibodies or sensitized lymphocytes tailored to each unique threat. Inflammation Inflammation is a key concept in pathophysiology, acting as a normal defense mechanism to localize and remove injurious agents. The signs and symptoms of inflammation serve as warnings of underlying problems. Definition Inflammation is the body’s nonspecific response to tissue injury, resulting in redness, swelling, warmth, and pain, and perhaps loss of function. Disorders are named using the ending -itis for inflammation. The root word is usually a body part or tissue; for example, pancreatitis, appendicitis, laryngitis, or ileitis. Causes of inflammation: 1-Physical agents (heat, cold, radiation, mechanical injury as splinters ,glass) 2-Chemical agents( acids, alkalis, poisons) 3-Ischemia or infarction(necrosis) 4-Immunological agents (allergic reactions) 5-Infective agents (bacteria, viruses , fungi, parasites) Types of inflammation Acute inflammation is a short-term, beneficial response to injury or infection, while chronic inflammation is a persistent and potentially harmful condition. Feature Acute Inflammation Chronic Inflammation Onset Rapid Slow Duration Short-lived (days to weeks) Long-lasting (months to years) Cause Sudden injury, infection, or irritant Unresolved acute inflammation, autoimmune diseases, chronic irritants Key Cells Neutrophils Macrophages, lymphocytes Tissue Minimal tissue damage, usually Tissue destruction, fibrosis, potential Changes resolves completely for systemic effects local effects of inflammation: Redness (rubor or erythema): Caused by increased blood flow into the damaged area. Heat: Also due to increased blood flow. Swelling (edema): Caused by the shift of protein and fluid into the interstitial space. Pain: Results from increased pressure of fluid on nerves and local irritation by chemical mediators like bradykinins. Loss of function: May develop if cells lack nutrients or if swelling interferes with function, such as restricted joint movement. Example of inflammation and healing : Burns Causes of burns: Thermal-caused by flames or hot fluids Chemical Radiation Electricity Light Friction Classifications of Burns : Burns are classified based on - the depth of skin damage - the percentage of body surface area involved Classifications of Burns based on the depth of skin damage First degree burns (Superficial Partial-Thickness Burns): Involve the epidermis and possibly the upper dermis. Appear red and painful but heal without scarring (e.g., mild sunburn or scald). Second degree burns (Deep partial-thickness Burns): Damage the epidermis and part of the dermis. Characteristics include redness, edema, blisters, and hypersensitivity. Healing may be difficult and may require grafts, with increased infection risk and potential scarring. Third degree burns (Full-Thickness Burns): Destroy all skin layers and underlying tissues, leading to a hard, dry, charred area. The damaged tissue may shrink, causing pressure and requiring escharotomy to improve circulation. They initially numb due to nerve destruction but become extremely painful as inflammation occurs. They necessitate skin grafts for healing. Assessment of burn area using the rule of nines.  Pathophysiology (1) (MBS 213) Lecture 1 Introduction to Pathophysiology and Laboratory medicine Language of pathophysiology Pathophysiology = the study of functional or physiologic changes in the body that result from disease or injury Health:(World health organization, WHO), state of complete physical ,mental and social well-being Disease : may be defined as : a deviation from the normal state of health (physical , mental and social wellbeing ) Disease is loss of homeostasis of the body Homeostasis: Ability of the body to maintain nearly constant conditions in the internal environment (Set point of B.P. , Temperature, electrolyte and hormone levels) As frequent minor changes occur in the body, the compensation mechanisms respond, and homeostasis is quickly restored. What are the categories of etiology(Causes of diseases) Genetic disease(inherited) Genes are responsible for a structural or functional defect Congenital disease(anomalies/malformations): disease occurring at birth Acquired disease :disease caused by factors after birth Terms used in describing the characteristics of a particular disease -Pathogenesis; development of disease or the sequence of events involved in the tissue changes related to the specific disease process. Stages and clinical course: 1- An acute disease ; a-sudden onset/develop quickly b-short term illness c-severe or marked manifestations ex: acute appendicitis 2- A chronic disease ; a-slow onset/develop gradually b-long term illness c-mild nonspecific manifestation ex: rheumatoid arthritis Stages and clinical course Convalescence (rehabilitation): The period of recovery and return to the normal health state; it may last for several days or months. Complications : New secondary or additional problems develops from an existing illness, arise after the original disease begins. For example, following a heart attack, a person may develop congestive heart failure, a complication. Terms used in describing the characteristics of a particular disease Prognosis :- the probability of the patient for recovery. Or the probable outcome of a disease Morbidity indicates disease rate within a group Mortality: the relative number of death resulting from a particular disease. Epidemiology : The science of tracking the pattern or occurrence of disease Endemic disease = disease native to local area Epidemic disease = higher than expected number of cases of an infectious disease within a given area (spread quickly) Pandemic disease = higher NO. of cases in many region of the globe Give an example of disease may occur sporadically as well as in epidemic or pandemic outbreaks. Notifiable or reportable diseases must be reported by the physician to certain designated authorities. Ex: SARS, AIDS Epidemiology The frequency of a disease is tracked by recording two factors, the incidence and the prevalence Incidence = NO. of new cases in specific population within specific time Prevalence = total No. of new and old cases in specific population within specific time. Prevalence is always a larger figure than incidence Cellular Adaptations Cells can adapt to stress to prevent injury through; 1-Changes in size of individual cell; Atrophy/hypertrophy 2-Changes in actual number of cells -hyperplasia 3-Change in Type of Cells -metaplasia/neoplasia