Jan. 22nd (Exam 1) Flashcards
What is differentiation?
Differentiation is the process of cells becoming more and more specialized until they become what we call terminally differentiated cells.
What are the large granular lymphocytes?
Give an example.
What will these specific cells do?
They are the effector cells of innate immunity, containing a granular cytoplasm (histamine, maybe heparin)
NK cells.
They enter the infected tissue to kill infected cells, releasing cytokines.
What are the small lymphocytes?
Give two examples.
How do they typically exist within the body?
They are cells that are involved in the adaptive immune system and contain almost no cytoplasm.
B-cells and T-cells
They circulate within the blood in what is called a quiescent form.
What are the cell-surface receptors present on B lymphocytes/cells?
Immunoglobulins
What are plasma cells?
These are the effector (mature form) of B cells that act to secrete antibodies.
What are antibodies?
These are the soluble form of immunoglobulins.
What do T lymphocytes have that is similar to immunoglobulins?
They have T-cell receptors.
These are NEVER secreted.
Is there any variation present within the “arm” part of the immunoglobulin/antibody?
No there isn’t much variation in the constant part, because the gang sign part can have unbelievable variation.
What are the different “regions” of the immunoglobulins, antibodies, and T-cell receptors?
- Transmembrane region (not antibodies)
- The constant region (within one class of antibodies)
- The variable region
What are the three (effector) functions of B-cells that we talked about?
- Differentiating into plasma cells to make antibodies
- Humoral Immunity
- Opsonization
What is humoral immunity?
This is the broad immunity due to antibodies and ALL their actions.
Example that was shown was bacterial toxins being neutralized by specific antibodies.
What is opsonization?
This is the coating of a bacterium with antibodies to enhance phagocytosis.
What are the two broad types of effector T-cell?
- Cytotoxic T-cells
- Helper T-cells
What is a regulatory T-cell?
What does this essentially prevent?
This is a type of helper T-cell that controls the activity of other T-cells to prevent tissue damage and stop immune response.
The immune system attacking itself when it labels cells as damaged.
What do cytotoxic T-cells do?
They will kill cells that are infected with certain viruses or bacteria.
What do Helper T-cells do?
What determines which types of cells will be activated?
They will secrete cytokines to help other cells become effector cells (example could be activation of macrophages).
They type of cytokines that are produced.
Where are most lymphocytes found?
In lymphoid tissues or organs.
Where were the 8 different locations that we listed as lymphoid tissues or organs?
- Bone marrow
- Thymus
- Spleen
- Adenoids
- Tonsils
- Appendix
- Lymph nodes
- Peyer’s patches (small intestine)
What constitutes the primary/central lymphoid tissues?
What are the two central lymphoid tissues we talked about?
Where lymphocytes develop and mature.
Bone Marrow - origination site of B and T cells (where B cells will mature)
Thymus - maturation site of T-cells
What constitutes the secondary/peripheral lymphoid tissues?
What are the secondary/peripheral lymphoid tissue?
Location where mature lymphocytes are stimulated.
Everything else from the list of 8!
What are lymphatics?
Where do lymphatic vessels originate?
What do they do?
They are the networks of lymphatic vessels.
They originate in the connective tissues.
They collect the plasma that leaks out of blood vessels.
Where do lymph nodes lie?
They lie at the junctions of lymphatics.
Are lymph nodes primary or secondary lymphoid tissue?
Secondary or peripheral.
What does the lymphatic system generate?
What is it?
Where does it eventually go?
It generates lymph.
Lymph is a extracellular fluid
It is eventually returned to the blood.
What do T and B cells use to travel through the body?
They use the blood and lymph.
What happens to a lymphocyte if it is activated by a pathogen?
How does a lymphocyte get into the lymph node from the blood vessel?
It will stay in the lymph node.
Through the afferent lymphatic vessel.
What if a lymphocyte is not activated by a pathogen?
Where does the cell go and how does it get there?
It will eventually leave via the efferent lymph and will return to the blood
What is lymphocyte recirculation?
This is the movement of lymphocytes between the blood and the lymph.
Why is lymphocyte recirculation so advantageous?
Because it allows the lymphocyte population to continually survey the secondary lymphoid organs for infection.
Following an infection, what is the most commonly infected tissue?
What would be contained in the infected area regarding the pathogen and possible immune cells?
What happens to this stuff?
Connective tissue.
- Intact pathogens
- Pathogen fragments
- Pathogen-infected Dendritic Cells
This will all be carried to the nearest lymph node by the lymphatics.
What is the draining lymph node?
This is the particular lymph node that is receiving the fluid that is collected at the infection site.
What causes swollen glands?
When pathogen specific B cells proliferate in masse at what is called the germinal center of lymph nodes.
Why are lymph nodes considered to be secondary lymphoid tissue when B-cell proliferation happens here?
Because the development and maturation of B-cells happens in the primary lymphoid tissue (the Bone marrow), but the stimulation and subsequent proliferation happens in the secondary tissues.
What is the spleen?
Is it a primary or peripheral/secondary lymphoid tissue?
The spleen is a lymphoid organ that serves as a filter for the blood.
It is peripheral, or secondary.
What are the two functions of the spleen?
- Remove the damaged or senescent red cells.
- Defends against blood-borne pathogens.
What type of tissues exists within the spleen?
- Red Pulp - where the red blood cells are monitored and removed.
- White Pulp - where the WBCs gather to provide adaptive immunity.
Why are humans able to survive without a spleen?
Other organs like the liver and the bone marrow can be utilized to filter the blood and the immune system can compensate.
Where are most microorganisms found in humans?
- Respiratory tract
- GI tract
What does GALT stand for?
What are the four tissues?
Gut-Associated Lymphoid Tissues
- Tonsils
- Adenoids
- Appendix
- Peyer’s Patches
What does BALT stand for?
What does this tissue line?
Bronchial-Associated Lymphoid Tissue
It lines the respiratory epithelium.
What does MALT stand for?
What does “more diffuse mucosal lymphoid tissue” mean?
Mucosa-Associated Lymphoid Tissue
This type of tissue exists as follicles or scattered lymphoid cells. Essentially, they are spread out.
What are M cells?
What do they do?
They are the specialized cells of the mucosal epithelium.
They assist in getting the pathogens to the MALT
How do the lymphocytes get to the MALT?
How do they leave?
What determines if they will stay?
They enter the MALT through the blood.
They leave through the efferent lymph.
If they are activated.
