chap 5 ap Disease and Disease-Producing Organisms

Overview of Disease and Disease-Producing Organisms

Definitions of Disease

• Disease: An abnormality of structure or function of part, organ, or system.
  • May be felt or observed by others.
  • Known or unknown cause.
  • Severity of effects may vary.

Categories of Disease

• Infection
• Degenerative diseases
• Nutritional diseases
• Metabolic disorders
• Immune disorders
• Neoplasms
• Psychiatric disorders

Predisposing Causes of Disease

1. Age: Different age groups are more susceptible to certain diseases.
2. Gender: Males and females can be predisposed to different diseases based on biological factors.
3. Heredity: Genetic factors can increase risk.
4. Living conditions and lifestyles: Environmental and lifestyle choices can predispose individuals to diseases.
5. Emotional disturbances: Stress and mental health can influence physical health.
6. Physical and chemical damage: Injuries or exposure to harmful substances can lead to disease.
7. Pre-existing illness: Existing health issues can exacerbate or predispose to new diseases.

Epidemiology

• Epidemiology: The study of the cause of disease in populations. It involves statistics like:
  • Incidence rate: The number of new cases in a specified time.
  • Prevalence rate: The total number of cases over a period.
  • Mortality rate: The number of deaths caused by a disease.
  • Categories: Epidemic, endemic, pandemic.

Disease Diagnosis, Treatment, and Prevention

• Key terms include:
  • Acute: Rapid onset, short duration.
  • Chronic: Long-lasting or recurrent disease.
  • Therapy: Treatments used to manage disease.

Treatment Types

• Medication: Chemical substances for treatment.
• Surgery: Operative procedures.
• Physical therapy: Exercise and rehabilitation methods.
• Occupational therapy: Support for daily living activities.
• Nutritional therapy: Diet management for health.

Disease Prevention Strategies

• Promote a healthy lifestyle:
  • Stop smoking.
  • Limit alcohol use.
  • Eat a healthy diet.
  • Maintain a healthy weight.
  • Regular exercise.

Infectious Disease

• Pathogens: Disease-causing microorganisms, including:
  • Bacteria: Single-celled organisms; treated with antibiotics.
  • Viruses: Require host cells to replicate.
  • Fungi: Simple plantlike organisms, can be pathogenic (e.g., Candida).
  • Protozoa: Animal-like, single-celled organisms (e.g., Giardia).

Modes of Transmission

• Direct: Immediate transfer between hosts.
• Indirect: Spread through vectors or contaminated objects.

Portals of Entry

• Skin (especially if damaged)
• Respiratory tract
• Digestive system
• Urinary and reproductive systems

Microbiology: Study of Microorganisms

• Microorganisms categorized based on type and characteristics:
  1. Bacteria: Lack a true nucleus (e.g., Staphylococcus).
  • Shapes: Cocci, bacilli, spirilla.
  1. Viruses: Consist of nucleic acid and proteins; can only replicate within living cells.
  2. Fungi: Includes yeasts (single-celled) and molds (multicellular).
  3. Protozoa: Includes various classes like amebas, ciliates, flagellates, and apicomplexans.

Microbiome

• Definition: The population of beneficial microorganisms in and on the human body.
• Benefits: Prevents infections, synthesizes nutrients, and promotes immune tolerance.
• Disruptions can lead to disease.

Multicellular Pathogens

• Parasitic Worms: Study of parasitic worms (helminthology).

  • Includes:
  • Roundworms: e.g., Ascaris, hookworms.
  • Flatworms: e.g., tapeworms.

• Parasitic Arthropods: Insects and spiders that can act as vectors for diseases.

Microbial Control Measures

• Sterilization: Complete destruction of all microorganisms.
• Disinfection: Elimination of most microorganisms except spores.
• Public health measures to prevent microbial spread include:
  • Sewage and garbage disposal
  • Water purification
  • Food contamination prevention
  • Pasteurization

Antimicrobial Agents

• Antibiotics: Specifically treat bacterial infections; caution against resistance.
• Antiviral agents: Block viral replication and production.

Laboratory Identification of Pathogens

• Identification methods include:
  • Observing growth characteristics.
  • Utilizing stains (e.g., Gram staining).
  • Performing serologic tests for immune responses.

Word Anatomy for Disease Terms

• Iatro-: physician (iatrogenic disease)
• Idio-: self (idiopathic disease)
• Pan-: all (pandemic)
• Pre-: before (predisposing)
• Psych/o-: mind (psychiatry)
• Chir/o-: hand (chiropractic)

Summary

• Understanding disease involves recognizing its definitions, categories, causes, modes of transmission, and control measures. Awareness of the microbiome’s role in health is vital. Treating and preventing diseases often requires a combination of lifestyle changes, therapies, and public health interventions.