Exam 3 | Immune & Lymphatic Flashcards
What does the immune system do?
The immune system is responsible for protecting the body from foreign agents (pathogens) by launching an internal immune response when foreign entities are detected. A similar response is also initiated after physical (internal or external) injury, and contributes to the symptoms of allergies and autoimmune diseases.
What does the lymphatic system do?
The lymphatic system supports the immune system by circulating lymph fluid through specialized vessels and lymph nodes, where several immune cells are formed
What structures are a part of the lymphatic system?
The thymus, spleen, and tonsils are all specialized structures that are considered to be part of the lymphatic system, as well as (red) bone marrow, skin, and internal mucous membranes such as those in the nasopharynx.
What are pathogens?
Foreign invaders that can cause infection and/ or disease once they enter the body are collectively known as pathogens.
What are the 6 different types of pathogens?
There are 4 that are considered living/cellular (organic):
Parasites
Protozoa
Fungi
Prokaryotes
There are 2 that are considered nonliving/acellular (inorganic):
Virus
Prion
What are parasites?
Parasites are the largest of all pathogens shown here; can cause serious problems like tapeworm. Live inside host and consume nutrients from host. Rare in developed parts of the world, from contaminated food/water
What are protozoa?
Malaria is from a mosquito that’s infected by a protozoa. Protozoa infects mosquito and lives inside it so when the mosquito bites a person, we get infected.
What are fungi?
Fungi can be drug resistant which has been causing a lot of problems. Athlete’s food is a common problem due to the dark, wet environment
What are prokaryotes?
Bacteria; common example is leprosy
What’s a virus?
Viruses are a problem considering they can effect humans from animals; common example is AIDS
What’s a prion?
Prions are misfolded proteins that when coming into contact with other proteins in the body, it causes them to misfold as well. We have no way to fight against prion based diseases. CJD (mad cow disease) causes very serious cognitive decline and neurological problems
What are other exogenous triggers that can cause an immune response?
Physical injuries (internally or externally) & allergens
How do injuries trigger an immune response?
Injuries typically trigger the first line of defense in the immune response, resulting in what is known as an inflammatory response
(sometimes also referred to as an “inflammatory soup”, due to the plethora of signaling molecules released as part of this inflammatory response).
How do allergens trigger an immune response?
Allergens, which are not considered to be pathogens as they do not typically cause infection or disease upon entering the body, but are nevertheless interpreted as “foreign” by immune cells and targeted with an immune response that is typically associated with an increased release of the chemical histamine.
As with the inflammatory response, release of histamine results in increased local inflammation.
How do autoimmune diseases impact our immune response?
An endogenous trigger of the immune response is observed in autoimmune disorders, an example of which we discussed in the first quarter of the course (rheumatoid arthritis).
A hallmark of autoimmune disorders is a triggering of the immune response due to normal, endogenous cellular activity, which can often lead to inflammation and a cascade of other physiological effects. Body often attacks its own cells as if they were foreign
What are the two classes of immune cells and what progenitor cell do they derive from?
Lymphocytes originate from lymphoid stem cell. They are closely associated with (produced in) structures of the lymphatic system.
Granulocytes originate from myeloid progenitor. They’re hite blood cells that contain a specialized organelle known as a granule in their cytoplasm. These granules typically carry enzymes that allow these cells to destroy and digest foreign invaders.
What are the three levels, or “lines” of defense in the mature human immune system?
The first level of defense is the most general in its targeting behavior, and relies primarily on the skin and other epithelial tissue to provide a physical barrier protecting the internal organs and cells from injury or pathogenic invasion. In most cases, physical injuries only require this level of defense in order to protect the body from further harm.
The second level of defense is known as the innate immune system, and relies primarily on granulocyte activity (with some lymphocyte activity, specifically from Natural Killer Cells). This form of immunity is also relatively nonspecific, in terms of targeting behavior, but is more robust than the inflammatory response associated with the first level of immunity.
The third level of defense is known as the adaptive immune system, and relies primarily on lymphocyte activity, with granulocytes still playing an essential role. This immune response is the most specific in its targeting of pathogens, and the cornerstone of this response are the antibodies produced to bind specific antigens.
What is the innate immune system?
It is the second line of defense in the body, and relies on pre-existing granulocytes and nonspecific antibodies to target foreign invaders that escape the first line of defense (the skin).
In particular, neutrophils, macrophages, dendritic cells and natural killer cells are the first to respond to, detect and destroy pathogens, with the assistance of natural (nonspecific) antibodies capable of binding multiple different types of antigens.
This immune response is typically rapid and immediate, taking place over the course of several hours.
What is the adaptive immune system?
It is the third line of defense in the body, and relies on pre-existing (and newly-formed) lymphocytes (B & T cells) and specific antibodies to target foreign invaders that escape the second line of defense.
As a result, this immune response is much more prolonged, taking place over the course of several days.
What is the essential protein that aids both innate and adaptive immune system?
antibodies
What are antibodies?
Antibodies are unique proteins that typically bind to a specific molecule, or antigen and recruit other immune cells (often lymphocytes) to attack the antigen or pathogen from which the antigen originated
Why are antibodies important?
Endogenously, antibodies are essential for an immune response to occur, and are often the “initial detectors” of foreign invaders.
Exogenously, the specific binding behavior that is a hallmark of antibodies makes them excellent tools for molecular visualization through techniques such as immunocyto- and immunohistochemistry.
What are antibodies referred to and what makes their structure unique?
Antibodies are also referred to as immunoglobulins.
Most antibodies actually have a characteristic “Y-shape” to them, with the internal secondary and tertiary structures creating the heavy chains of the antibody, while the external secondary and tertiary structures comprise the light chains.
What are the 5 classes of antibodies?
IgG, IgM, IgA, IgD, IgE
