Understanding Health, Disease, and Medical Interventions

Key Concepts in Health and Medicine

Fundamental Definitions

• Medicine: The social institution responsible for treating disease and restoring or improving the health of a population.
• Health: A state of complete physical, mental, and social well-being.
• Disease: Usually defined as a structural or physiological dysfunction.
• Illness: The social and cultural response to a disease.

Vital Signs: Indicators of Health

Physiological parameters that inform us of our state of health or the evolution of a disease:

• Body Temperature: The balance between the heat produced by our body from metabolism and the heat it loses.
• Heart Rate: The number of heartbeats in one minute.
• Breathing Rate: The number of breathing cycles (inhale-exhale) in one minute.
• Blood Pressure: The pressure that the blood exerts on the artery walls.

Types of Diseases

• By Origin:
  • Infectious (e.g., measles)
  • Non-infectious (e.g., anemia)
• By Appearance and Duration:
  • Acute (e.g., flu)
  • Chronic (e.g., arthritis)
• By Incidence in the Population:
  • Sporadic (e.g., heart attack)
  • Epidemic (e.g., cholera)
  • Pandemic (e.g., AIDS)
  • Endemic (e.g., malaria)

Pathogens Causing Diseases

Diseases can be caused by various microorganisms and agents, including:

• Bacteria
• Protozoa
• Fungi
• Viruses

Disease Transmission

Transmission occurs when a pathogen, such as a virus, enters a healthy body. Common ways of transmission include:

• Direct Contact: Pathogens pass directly from one individual to another without an intermediary.
• Touching Inert Objects: Objects act as vehicles for transmitting microorganisms.
• Drinking Water: Water can be contaminated by pathogens.
• Food: Food can also be infected with pathogens.
• Air: Microorganisms travel on dust particles or freely in the air.
• Animals: Animals can carry pathogenic microorganisms without necessarily having the disease themselves.

Body Defenses Against Pathogens

External Defenses

These defenses prevent pathogens from entering our bloodstream:

• Structural: Skin and mucous membranes act as physical barriers.
• Biochemical: Saliva, tears, and gastric juices help eliminate pathogens.
• Mechanical: Cilia prevent pathogens from settling.
• Ecological: Beneficial bacteria in the digestive and respiratory systems help eliminate harmful microorganisms.

Internal Defenses (Leukocytes)

White blood cells, known as leukocytes, eliminate pathogens once they are inside the blood:

• Non-Specific Defenses: Attack any foreign substance.
  • Phagocytes: Eliminate pathogens by digesting them.
  • Inflammatory Response: More blood flows to the affected area (causing swelling) to eliminate foreign substances and the waste products of digestion, which can form pus.
• Specific Defenses: Involve lymphocytes that produce antibodies, which are specific for each type of pathogen. This process also produces immunological memory.

Medical Interventions

Vaccination

A weaker form of the illness is injected into the body. Your body then produces antibodies. When the real virus enters your body, you are already prepared to fight against it effectively.

Serum

Used in cases where a person has a weakened defensive system. Antibodies, known as serum, are directly injected into the body to provide immediate protection.

Medication

For viral infections, there are generally no medicines that directly fight viruses (medications primarily reduce symptoms). For bacterial infections, antibiotics are used.

Transplant

The process of transferring an organ, tissue, or cells from one person to another. Stem cells are increasingly being used to produce tissue because of their ability to differentiate into any type of cell.

Potential problems associated with transplants include:

• Organ Conservation: There is a limited time frame for preserving the organ.
• Surgical Complications: Transplants are complex operations with inherent risks.
• Rejection: The recipient's body may not accept the transplanted organ, leading to rejection.