imfe tion set 1

What are the two main types of body defenses?

Physical barriers and cellular defenses

What is a key physical barrier of the body?

Skin (keratin layers)

What structures act as mucous membrane barriers?

Nose and GI tract

What is phagocytosis?

Process where immune cells engulf and destroy pathogens

Which cells perform phagocytosis?

Neutrophils, monocytes/macrophages, NK cells, eosinophils, cytotoxic T cells

What initiates and sustains inflammation?

Inflammatory mediators

What are interferons and interleukins?

Immunogenic proteins (cytokines) secreted by WBCs

What is the function of cytokines?

Propagate immune response

What is the specific immune response characterized by?

Memory B and T cells

What causes fever during infection?

Pyrogen-activated rise in body temperature

Which WBC makes up up to 70% of total WBCs?

Neutrophils

Which WBC arrives first at tissue damage?

Neutrophils

What is the lifespan of neutrophils?

Up to 1 week

What are immature neutrophils called?

Band cells

What are the 3 types of lymphocytes?

NK cells, B cells, T cells

Where are monocytes found?

In blood

What do monocytes become in tissues?

Macrophages

What are Kupffer cells?

Liver macrophages

What are eosinophils primarily involved in?

Allergy response

What do eosinophils secrete?

Cytokines, leukotrienes, platelet activating factor

What are basophils responsible for?

Allergy response

What do basophils release?

Cytokines and histamine

What anticoagulant do basophils secrete?

Heparin

What type of immunity do immunizations create?

Active immunity

What do booster immunizations do?

Strengthen immune memory

What happens when an antigen is recognized by B cells?

B cells clone into plasma cells

What do plasma cells produce?

Antibodies (immunoglobulins)

What is the most common immunoglobulin?

IgG

How fast can antibodies be produced?

About 2000 per second

What is the function of antibodies?

Neutralize or mark pathogens for destruction

What do memory B cells do?

Remember antigen for faster future response

What do T helper cells do?

Activate B cells and secrete cytokines

What do cytotoxic T cells do?

Destroy infected cells

What do T memory cells do?

Recognize antigen quickly upon re-exposure

What causes decreased WBCs?

Autoimmune diseases, drugs, chronic infection, cancer, malnutrition

How do glucocorticoids affect immunity?

Immunosuppress immune function

What is an example of an immunosuppressive drug?

Infliximab

How do chronic infections affect WBCs?

Deplete due to prolonged immune demand

What congenital condition affects immunity?

DiGeorge syndrome

How does cancer affect WBCs?

Interferes with production and maturation

What 3 factors are required for infection?

Host susceptibility, pathogen, transmission

What is pathogenicity?

Ability of organism to overcome defenses

What are the 2 mechanisms of pathogenicity?

Strength in numbers and toxin production

What is virulence?

Power to produce disease

What is an example of a toxin?

Shiga toxin from E. coli

What is a port of exit?

Pathway pathogen leaves host (e.g. respiratory, GI)

What is a port of entry?

Pathway pathogen enters host

What is the most common infection transmission method?

Hands

How long should hands be washed?

15–20 seconds

What is Clostridium botulinum?

Gram positive anaerobic bacteria producing neurotoxin

What does botulinum toxin do?

Blocks acetylcholine

What is the treatment for botulism?

Antitoxin (HBAT)

How is botulism prevented?

Nitrates/nitrites in preserved foods

What is direct contact transmission?

Physical contact with infected host

Give examples of direct contact infections

STIs, chickenpox

What is airborne transmission?

Inhalation of pathogens

Give examples of airborne infections

Cold, meningitis, measles

What is ingestion transmission?

Consumption of contaminated food

Give examples of ingestion infections

Food poisoning, Hepatitis A

What is nosocomial infection?

Hospital-acquired infection

What is community-acquired infection?

Infection acquired outside hospital

What is microflora?

Normal microorganisms in body

What is commensalism?

Host unaffected

What is mutualism?

Both host and bacteria benefit

Example of beneficial bacteria function

E. coli produces vitamin K2

What is parasitism?

Host is harmed

What is an opportunistic infection?

Infection when opportunity arises (e.g. immunocompromised)

What are the 3 types of parasites?

Protozoa, helminths, arthropods

Example of protozoa

Malaria

Example of helminth

Tapeworm

Example of arthropod

Lice, ticks, mites

What are fungi?

Eukaryotic organisms

What environments do fungi prefer?

Dark, moist environments

What are the 2 types of fungi?

Yeast and mold

Example of fungal infection

Candida albicans

What is superficial fungal infection?

Ringworm, thrush

What is systemic fungal infection?

Lung or GI infection

What are viruses made of?

Protein coat and nucleic acid

What do viruses require to survive?

Host cell

What can viruses do to host cells?

Alter or lyse them

Are viruses more or less contagious than bacteria?

More contagious

Examples of viral infections

COVID-19, influenza, cold

How are viral infections treated

Symptom management and antivirals

How are viral infections prevented

Immunizations

What are bacteria?

Prokaryotic organisms

What are plasmids?

Small DNA bodies involved in resistance

What are biofilms?

Bacterial colonies

What do bacteria often produce?

Toxins

What are bacteria classified by?

Gram staining

Examples of gram-negative bacteria

E. coli, Salmonella

Examples of gram-positive bacteria

Staphylococci, Streptococci

What is the suffix for inflammation?

-itis

Example of -itis

Appendicitis

What is the suffix for pathogens in blood?

-emia

Example of -emia

Bacteremia

What is incubation period?

Pathogen present, no symptoms

What is prodromal stage

Early nonspecific symptoms

What is acute stage

Maximum symptoms and pathogen load

What is convalescent stage

Recovery and repair

What is the first step in diagnosing infection

Determine location of illness