Jan. 15th (Exam 1) Flashcards
How should we define immunology?
Immunology is the study of the physiological mechanisms that organisms use to defend themselves against invasion of pathogens.
Can we understand the immune system as a whole by looking at all the various immune cells?
No. Included should also be important tissue, organs, and peptides that are important as a whole.
What are the three categories of defense?
- Barrier
- Innate
- Adaptive
Describe the barrier defense.
Barrier defense is the body’s first line of defense.
This includes physical surfaces like the skin and mucous membranes, as well as chemical components such as enzymes, antimicrobial peptides, and acidic pH that help prevent pathogen entry.
Define Epithelium.
Give a few examples of strong and vulnerable barriers within epithelium.
Epithelium is the tissue consisting of continuous layered cells that are continuous in our body; they line all surfaces internal and external.
Strong barriers are things like skin, hair, and nails.
Vulnerable barriers are mucosal surfaces (mucosae) which protect the epithelial tissue from damage and infection.
What is produced by ALL epithelia in an effort to kill pathogens by means of disrupting their membranes?
Antimicrobial peptides
What are four examples of fluids secreted by or near epithelial surfaces that have antimicrobial peptides?
What is one antimicrobial peptide that all of these epithial surfaces will have?
- Saliva - has lysozyme
- Tears - has lysozyme
- Gastric Juices - acidic
- Grool (vagina) - acidic
*all of these have defensins!
Define Pathogen.
Any organism that has the potential to cause disease.
What does it mean for a pathogen to be habitual or opportunistic?
Essentially, habitual pathogens typically cause disease in normal hosts whereas opportunistic pathogens don’t typically cause disease, but given certain circumstances (compromised immune system or access to sterile areas) allow them to cause disease.
What is immunization?
It is a prophylactic procedure given to prevent severe disease by prior exposure to the infectious agent in a form that cannot cause disease.
Try to explain the brief history of immunization.
Lady Mary Montagu first tried this out by taking small amounts of the smallpox virus via the pus of an infected individual and injecting that into someone else. This innovation brought the mortality rate of the disease from 25% to 2%.
Edward Jenner then improved on this idea by injecting small amounts of cow pox from cows into people who had small pox. This worked even better.
Reasoning for this surrounds around the idea that a small amount of cow pox is less similar to smallpox than a small portion of small pox is to small pox, yet still has the ability to introduce the immune system to peptides found on smallpox.
What are commensal microorganisms?
What do they do?
They are organisms that typically live in or on our body.
They don’t hurt us and they help us by making vitamins, processing of digested food, and protection from disease.
Define Microbiota.
Community of microbial species that occupy a specific niche within the body.
Just how would commensal microorganisms protect us from other pathogens?
They outcompete them for nutrients and even make general antimicrobial substances.
Walk through the general idea of the effects that antibiotics have on commensal organisms.
Antibiotics kill the large colonies that normally exist within the gut microbiome.
Pathogenic bacteria are then able to gain foothold and release toxins that can damage mucosa.
Blood cells can then leak through the damaged epithelial cells.
What is mucosa?
Mucosa is a specialized tissue layer that is broader than epithelium i.e the epithelia is just a section of the mucosal tissue.
What are the four types of pathogenic organisms?
- Viruses
- Bacteria
- Fungi
- Parasites
Why are diseases most acute upon original introduction to a population?
Because relationships between pathogens and hosts can change over time.
The pathogen “evolves” or acquires adaptations that facilitate transmission.
Not advantageous for the host to die right away…
What would be considered a endemic disease that is common among human populations to which humans can gain lifetime immunity from?
Chicken Pox.
Generally define the innate category of defense.
Would innate or adaptive be the most specific in range of response?
Innate Response is what we are born with and is initiated immediately upon breaching of the barriers.
Innate Responses are very general and cast a wide net for pathogens.
Explain the two-part response of the innate immune system.
How the pathogen is recognized:
soluble proteins within the serum and protein-surface receptors bind to either the pathogen itself, its products, or cells that have been altered.
How the “boys” are gathered for a response:
Effector mechanism are used to destroy and remove pathogens. This is essentially the short way of saying there is a sequence that needs to happen before effector cells show up.
What are effector cells?
Cells that have an effect…
That effect might be killing a cell that is infected by a virus, engulfing an entire bacteria, or by attacking a parasite.
Ex. Macrophages, NK cells
What is the complement of the immune system?
Complement is a series of serum proteins that act to mark pathogens so they can kill them or so that effector cells can be recruited to kill them.
You can think of these guys as “little helpers” to the immune cells that often directly combat pathogens in all areas of the immune system.
Define Innate immunity.
Innate Immunity comprises a genetically programmed set of responses that can be mobilized immediately when an infection occurs.
They are the host defense mechanisms that act at the start of an infection
