Intro to Pathology-Ch1

1. Intro to Pathology-Ch1 Marilyn Rose RT, RDMS

2. Outline • Disease • Inflammation • Edema • Ischemia and infarction • Hemorrhage • Alterations of cell growth • Neoplasia • Hereditary Diseases • Disorders of Immunity • Infectious disease Exposure • AIDS

3. Disease • Pathology • Study of diseases that can cause abnormalities in structure or function. • Disease= pattern/ deviation - body’s response to injury • Disease- manifest in set of characteristics- sign/symptom • hereditary • Traumatic • Infectious • vascular • metabolic

4. Disease • Signs • measurable/ objective • Symptoms • experiences patient feels/ describes- subjective • Neoplastic- alterations in growth • Iatrogenic- Physician cause • Nosocomial- development of infection in acute care facility • Community acquired- develop outside acute care facility • Idiopathic- underlying cause unknown

5. Manifestations of disease • Inflammation • Edema • Ischemia/ infarction • Hemorrhage • Neoplastic • In addition: • Hereditary diseases • Immune reactions- AIDS

6. Inflammation • Acute= initial response to injury • Types- blunt/ penetrating, infectious, irritating chemical • Response – 4 overlapping events • 1. Alteration in blood flow • hyperemia & creation of exudate • Result is pressure/ nerve pain • 2. Migration of leukocytes • 3. Phagocytosis- digest debris • 4. Repair • return normal structure/ function & scar formation • fibrous scar can cause narrowing / adhesions or externally = keloid • Ex. Cirrhosis= irregular lobules and bands of scar tissue • 5 clinical signs • Rubor, calor, tumor, dolor and loss of function • Systemic reaction- fever

7. Edema • Accumulation of abnormal amounts of fluid in intercellular tissue/ space • Localized- elephantiasis • inflammatory rxn or lymphatic obstruction • Generalized- anasarca • CHF, cirrhosis of liver, renal disease • Dependent portions of the body • Ambulatory- fluid accumulates- ankles/ lower legs • Non-ambulatory- sedentary- fluid accumulates in lower back, sacral areas and lungs. Extravascular fluid can accumulate in serous cavities: Pleural Pericardial Peritoneal Can result in minimal or dire consequences.

8. Ischemia/ infarction • Ischemia- interference with blood supply to an organ- deprive O2 and nutrients • Atherosclerosis • Thrombotic/ embolic occlusion • The overall affect depends on: • collateral formation • Rate of development of occlusion • Vulnerability of tissue to hypoxia • O2 capacity of the blood • Infarct- localized area of ischemic necrosis • Myocardial/ pulmonary- most common- thrombotic/ embolic occlusion • Infrequent- volvulus, compression (hernia), adhesion trapping • Result is gangrene • Example???? (Hint Diabetes)

9. Hemorrhage • Hemorrhage- rupture of a blood vessel- artery/ vein • External- volume loss • Internal- hematoma • Body cavity- • hemothorax, hemopericardium, hemoperitoneum, hemarthrosis • Petechiae- minimal skin hemorrhage • Purpura- larger hemorrhages • Ecchymosis- >1-2 cm- bruise • Volume, rate and size and site… • Lg. amount in brain can cause death • External- loss of iron and anemia

10. Alterations of Cell Growth • Atrophy- reduction in size or number of cells in organ or tissue with a decrease in function. • Disuse atrophy- limb in plaster cast • Pathologic- loss of innervation, hormone, decreased blood supply • Ex. Atrophy of kidney- renal artery stenosis • Hypertrophy- increase size of cells for increased function • Not Hyperplasia which is an increase in number of cells • Ex. Myocardial hypertrophy- increase cardiac output due to > peripheral resistance • Hyperplasia= injury repair, increase in bone marrow cells-anemia • Dysplasia- loss of uniformity of cells and orientation • Chronic irritation • premalignant

11. Neoplasia • Neoplasia= • new growth- abnormal proliferation of cells • Cachexia- neo cells act as parasite- pt weak/ emaciated • Benign- closely resemble cells of origin • Can have severe consequences by position or hormone secretion • Ex. Pituitary, islet of Langerhans, brain, spinal cord, esophagus • -oma • Malignant- invade/ destroy adjacent structures- metastasize • Cancer= Latin- crab- fingerlike projections extending to other tissues. Carcinoma- malignant- epithilial, skin, mucous membranes Adenocarcinoma- glandular- breast, liver, pancreas, GI Squamous cell- lung, head and neck Sarcoma- connective tissue- bone, muscle, cartilage, Less common

12. Carcinogens/Spread • Chemical- DNA mutation • DNA/RNA viruses can cause neoplastic transformation • Pain is NOT an early sign of cancer • Cancer patients are immunologically compromised from disease/ irradiation/ chemo • More susceptable to opportunistic infections • Pneumocystis carinii (jirovecii ) • CMV • Screening most common for: breast (mammo) , cx (Pap) Malignant CA spread 1. seeding- invade a natural body cavity 2. lymphatic- lung/ breast 3. hematogenous- neoplastic emboli

13. Grading/ Research • Grading- aggressiveness, degree of malignancy, response to therapeutic agents. • Staging- extensiveness of a tumor, primary site and weather or not metastases to lymph nodes, liver, lungs and bone. • Epidemiology- study of determinants of disease in a population • Morbidity- rate an illness occurs • Mortality- depending on stage- calculate expected death rate

14. Hereditary Disease • Enzyme deficiency- most common • Decrease- albinism- absence of pigmentation • Accumulation- phenylketonuria- toxic levels of amino acid • Defect in globin- sickle cell/ thalassemia • Mutations- alterations in DNA- radiation, chemical, virus Dominant gene- produce the effect- female/male (1/2) Achondroplasia, neurofibromatosis, Marfan’s Recessive- only manifest when homozygous- siblings (1/4) Cystic fibrosis, glycogen storage, Tay-Sachs, sickle cell Codominant- AB blood Sex linked- x chromosome- mainly sons Color blindness, hemophilia, muscular dystrophy

15. Immunity disorders • Antibodies- immunoglobulin lymph nodes, thymus and spleen • An infant has some immunity at birth most acquired naturally by disease exposure or Immunization • Active- form antibodies counteract antigen as vaccine – low dose of dead bacteria/virus- promote antibody production • Toxoid- chemically altered toxin- poison from pathologic organisms • Ex. Smallpox, polio, measles, tetanus, diphtheria- booster • Passive- dose of preformed antibodies from an animal (horse) works immediately, lasts short time- used when person exposed to hepatitis, rabies, tetanus… has no immunity to it 1. Mast cells- release histamine- hay fever, asthma, gi allergies Systemic- analyhlactic- reactions- hypotension, shock, urticaria, laryngeal edema- in hypersensitive to bees, wasps, penicillin and IODINATED CONTRAST MEDIA 2. cytotoxic- antigen attach to cell wall RBC-transfusion, Rh 3. delayed reaction- previously sensitized to antigen- 2nd, 3rd exposure are more severe….principal of organ transplant rejection

16. Infectious Disease/ Exposure • Standard precautions- exposure to HIV, HBV can be minimized with PPE • Transmission based- contact, droplet, airborne • AIDS- RNA- HIV • Recurrent opportunistic infections • Kaposi’s sarcoma • Lungs, GI and CNS most affected • Pulmonary- P. jirovecii pneumonia- fatal • GI- sexually transmitted (rectum/colon), Kaposi’s, mets to small bowel- “bulls eye” lesions • CNS- dementia, mass lesions show focal neurologic symptoms • MRI best for manifestations of AIDS • - brain abscess, meningeal- toxo, cryptococcosis, CMV and herpes and • lymphoma of CNS