Understanding Infectious Diseases, Chronic Conditions, and Genetic Disorders
Infectious Disease Transmission Routes
- Air: Tuberculosis, diphtheria, cholera.
- Water and Food: Typhoid, salmonellosis, trichinosis.
- Animal Vectors: Malaria, sleeping sickness.
Infection and Infectious Agents
Infection results from the establishment and multiplication of microorganisms within the body. Microbial infection follows these four phases:
- Colonization of the cell surface.
- Penetration of defensive barriers.
- Invasion.
- Propagation and production of abnormalities in tissues and organs.
Bacterial Diseases and Toxins
Bacterial toxins are substances produced by bacteria, either secreted externally or retained within the bacterial cell.
- Tuberculosis: Spread through the air; causes serious pulmonary injury.
- Cholera: Transmitted via contaminated water and food; causes diarrhea, vomiting, and high fever.
- Meningococcal Meningitis: Characterized by neck pain, headaches, and skin spots.
- Pneumonia: Often follows a cold or flu; causes fever and respiratory difficulty.
- Tetanus: Contracted through open wounds; an exotoxin reaches the nervous system, causing violent muscle contractions.
Diseases Caused by Viruses and Prions
Examples include rabies, smallpox, and HIV-induced AIDS, which attacks helper T cells, resulting in immune system suppression. Prions can cause spongiform encephalopathy.
Diseases Caused by Animal Parasites
- Ectoparasites: Reside on the surface of the body.
- Endoparasites: Live in internal body cavities, utilizing temporary hosts.
Cardiovascular Diseases
- Atherosclerosis: Thickening of artery walls due to plaques.
- Thrombus: A blood clot in an artery or vein.
- Aneurysm: Narrowing or weakening of an artery that can rupture, causing hemorrhage.
- Stroke: Interruption of blood flow to the brain.
- Coronary Artery Disease: Narrowing or obstruction of arteries supplying the myocardium, potentially leading to a heart attack.
Oncological Diseases
These involve a loss of control over cell division. A cancerous tumor proliferates, forming a mass with invasive capacity. When cells spread via the bloodstream to form new tumors, it is called metastasis.
Immune and Metabolic Disorders
- Obesity: Weight increase due to fat accumulation.
- Type 2 Diabetes: A chronic illness characterized by hyperglycemia due to a lack of insulin.
- Eating Disorders: Includes anorexia and bulimia.
Hereditary and Congenital Diseases
- Hemophilia: An inherited defect that prevents blood clotting.
- Muscular Dystrophy: Leads to progressive muscle weakness.
- Down Syndrome: A congenital condition often associated with mental disabilities.
Mental Illnesses
Includes schizophrenia, anxiety disorders, bipolar disorder, and attention deficit hyperactivity disorder (ADHD).
Degenerative Diseases Associated with Aging
- Osteoporosis: Loss of bone tissue resulting in discomfort, fatigue, and extreme fragility.
- Alzheimer's: A degenerative process of neurons leading to memory loss and the decline of intellectual faculties.