ALH 120 Unit 1: Objectives

ALH 120 Human Diseases

Define disease and give an example.

An altered function/physiology of a body organ or system; a structural/functional change that is abnormal and harmful

Define etiology and give an example.

The study of the causes of disease (e.g. a virus causing the flu)

Define pathology and give an example.

The study of disease, including its structural/functional changes and causes

Define manifestations and give an example.

The clinical evidence of disease — signs, symptoms, and laboratory findings

Define a sign and give an example.

A physical observation or measurement (e.g. temperature, pulse, blood pressure)

Define a symptom and give an example.

What the patient says or feels (e.g. pain, dizziness, dyspnea)

Define diagnosis.

Evaluating manifestations (signs, symptoms, lab findings) and patient history to determine the disease process present

Define prognosis and give an example.

The prediction of the disease outcome (recovery, permanent loss of function, or probability of survival)

What categories of tests/procedures are used to make a diagnosis?

Clinical/lab procedures, radiologic procedures (X-ray, CT, MRI, ultrasound, nuclear medicine), EKG, EEG, scopes, and PFTs

What are 3 ways inflammation may be triggered?

Infection (pathogenic organisms — bacteria, viruses, fungi; the most common trigger), Trauma/physical injury (e.g., stepping on a nail; also radiation, temperature extremes), and Foreign substances/allergens (antigens, chemical agents, drug reactions)

What are the 4 phases of the inflammatory process?

Histamine release, neutrophil exudation, monocyte exudation, regeneration & repair

What are 2 ways the inflammatory process may end?

Regeneration (same cell type replaces tissue) or repair (scar tissue via collagen)

What types of WBCs are involved in inflammation, and which perform phagocytosis?

Neutrophils, eosinophils, basophils, monocytes, and lymphocytes are involved; neutrophils and monocytes perform phagocytosis

List signs, symptoms, and test findings for inflammation.

Local: redness, swelling, heat, pain. General: fever and leukocytosis (elevated WBC count)

What are appropriate treatments for inflammation?

NSAIDs, steroids, antihistamines, antimicrobials, rest/gradual exercise, abscess drainage

How does acute inflammation differ from chronic inflammation?

Chronic results from a persistent causative agent, involves monocytes/macrophages, lymphocytes, and plasma cells (no neutrophils), has less severe manifestations, and can cause fibrosis

Give an example of Active immunity.

Receiving a vaccine, triggering the body to produce its own antibodies (long duration, but slow to act)

Give an example of Passive immunity.

Receiving doses of preformed antibodies after exposure to a serious disease (immediate but short-lived)

Type I Hypersensitivity (Immediate/Allergy) — give examples.

Asthma, dermatitis, angioedema, anaphylaxis

Type II Hypersensitivity (Cytotoxic) — give examples.

Blood transfusion reactions, Rh incompatibility (Erythroblastosis Fetalis)

Type III Hypersensitivity (Immune Complex) — give examples.

Glomerulonephritis, Farmer's lung, Rheumatic Fever

Type IV Hypersensitivity (Cell-Mediated/Delayed) — give examples.

Contact dermatitis, transplant rejection, tuberculin-type (PPD) reaction

Define autoimmunity.

An intolerance to self, where individuals develop antibodies to their own tissues or self-antigens

List examples of autoimmune diseases.

Lupus (SLE), Rheumatoid Arthritis, Multiple Sclerosis, Myasthenia Gravis, Scleroderma

AIDS — What is the etiology?

HIV, a retrovirus, spread via contaminated body fluids (blood, semen, vaginal secretions, breast milk)

AIDS — Describe the pathology.

HIV attaches to CD4 receptors on T-helper lymphocytes, replicates, kills the cell, and spreads, destroying immune function

AIDS — What are the manifestations?

ARC (enlarged lymph nodes, fever, fatigue, weight loss, night sweats) progressing to full-blown AIDS (opportunistic infections, malignancies, CNS damage)

AIDS — What are the treatments?

No cure; ARVs (often via HAART) combining drugs from different classes to control, not destroy, the virus

AIDS — What are the complications?

Opportunistic infections (viral, fungal, protozoan, mycobacterial) and malignancies (Kaposi Sarcoma, lymphoma, leukemia, etc.)

What is Non-Specific (Innate) Immunity? Give examples.

Present at birth, provides immediate general protection against ANY foreign agent. Examples: physical/chemical barriers, phagocytosis, natural killer cells, fever, interferon, inflammation

What is Specific (Acquired) Immunity? Give examples.

Effective against a SPECIFIC antigen, developing after contact with it. Includes Humoral Immunity (B cells/antibodies) and Cell-Mediated Immunity (T cells)

Describe the cell-mediated immune process and the cells involved.

T lymphocytes (activated lymphocytes) work directly to fight the foreign invader (antigen), without relying on antibodies

Describe the humoral immune process and the cells involved.

B lymphocytes produce antibodies (Ig) that bind antigens and tag them for destruction, leading to neutralization, precipitation, agglutination, opsonization, or complement fixation

Define the 4 abnormalities of cell growth.

Hyperplasia (increase in number of cells), Hypertrophy (increase in size of cells), Metaplasia (replacement of one tissue type by another), Neoplasia (increased cell proliferation independent of normal growth signals)

Compare/contrast benign and malignant tumors.

Benign: well-defined, encapsulated, resembles origin cell, confined, slow growth, not usually fatal. Malignant: invasive, vague borders, cellular atypia, metastasizes via blood/lymph, rapid growth, high fatality

Name a benign tumor found in cartilage. Name a malignant tumor found in bone.

Chondroma (benign, cartilage) and Osteosarcoma (malignant, bone)

How are benign vs. malignant neoplasms named?

Benign = tissue + "oma" (Adenoma, Osteoma, Lipoma). Malignant = tissue + "carcinoma" for epithelial origin (Adenocarcinoma) or + "sarcoma" for bone/muscle/cartilage/connective tissue (Osteosarcoma). Exceptions: Melanoma, Lymphoma, Glioma

Give examples of etiologies of malignant neoplasia.

Tobacco/Smoking and Diet/Obesity (largest contributors, 31% each), Sedentary Lifestyle, Occupational Exposure, Family History, Viruses, Alcohol, UV Radiation, Pollution; chemical carcinogen example: benzopyrene in tar

What are the limitations/drawbacks to surgical treatment of malignancies?

Not viable when a mass is inoperable, impractical, or would be harmful to the patient — radiation becomes the alternative in these cases

What two types of treatment for malignancies are often combined?

Chemotherapy and radiation

List treatments for malignant neoplasia.

Surgical (basic modality), Radiation Therapy (best for rapidly dividing tumors), Chemotherapy (often combined with radiation), Hormone Therapy (breast/prostate cancers), Immunotherapy (blocks tumor cells from deactivating T-cells)

Describe the chromosome aberrations in Down, Klinefelter, and Turner syndromes.

Down = Trisomy 21 (3 copies of chr. 21). Klinefelter's = Trisomy 23/XXY (males). Turner's = Monosomy 23/single X (females)

How do autosomal recessive diseases usually occur?

When two heterozygous carriers (each carrying one normal, one defective allele) mate

Give three examples of autosomal recessive disease.

Cystic Fibrosis, Sickle Cell Anemia, Phenylketonuria (PKU)

Describe how sex-linked inherited disease usually occurs and give an example.

The defective allele is transmitted from mother to son on the X chromosome. Examples: Hemophilia, Duchenne's Muscular Dystrophy, Color Blindness

What is the usual etiology for congenital defects?

Poor blood supply/oxygen delivery, maternal viral/intrauterine infections, environmental teratogens (medicines, chemicals, toxic substances, maternal health, physical factors)

Do offspring of parents with a congenital defect have a greater than usual chance of having the same congenital defect?

No — congenital defects are not passed on to future generations