Immunology
the study of the physiological mechanisms that humans and other animals use to defend their bodies
from invasion by other organisms
Immune System
cells that collectively are responsible for defense against infection
Vaccination/Immunization
prevention of disease by prior exposure to the infectious agent or a part of an infectious agent in a
form that cannot cause disease
Commensal Organisms
microorganisms that live in a healthy human and do not cause disease
Example of a Commensal Organism
Gut Flora
- aid in digestion
- help prevent disease by out competing pathogenic microorganisms
- antibiotic treatment kills much of the normal gut flora sometimes allowing opportunistic pathogens
to establish infection
Pathogen
any organism with the potential to cause disease
Opportunistic Pathogen
organisms that cause disease only if the bodies defenses are weakened or if they get in the wrong
place
4 Types of Pathogens
1. Bacteria
2. Viruses
3. Fungi
4. Parasites: including single celled protozoans and multicellular organisms (mainly worms)
What two surfaces form barriers against infection?
Skin and Mucosal Surfaces
Epithelium
composed of keratinized cells that forms an impermeable barrier
Mucosa (mucosal surfaces)
internal surfaces specialized for communication with the environment
Where are chemical barriers to infection present?
, on Skin and Mucosa
What are the 3 types of Chemical Barriers to infection?
1. Acids
2. Mucus
3. Defensins
Chemical Barrier- Acid
protect the skin, stomach and vagina
Chemical Barrier- Mucus
- thick fluid layer containing molecules to protect the body's cells from damage
- also contain enzymes to kill pathogens
Chemical Barrier- Defensin
antimicrobial peptides secreted by epithelial cells
Innate Immune Response
1st Line of Defense a pathogen encounters that can clear an infection.
Two Parts of Innate Immune Response
1st: Recognition
2nd: Destruction/ Effector Mechanisms
Effector Cells
engulf pathogens, virus infected cells and complement coated pathogens
Cytokines
molecules secreted by innate immune cells and are responsible for initiating immune response
3 Activities of Cytokines
1. Cause Vasodilation
2. Immune Cell Recruitment
3. Immune Cell Activation
Inflammation
overall effect of the innate immune response
- heat, pain, redness and swelling
Adaptive Immune Response
A branch of the immune system that becomes activated if a pathogen is not cleared by an innate
immune response.
Immunological/Long Term Memory