Question | Answer |
What are the two components of the lymphatic system? | 1) lymphatic vessels and 2) lymphoid tissues and organs |
What are the main functions of the lymphatic system? | Transports fluids back to the blood, plays an essential role in body defense & resistance to disease, and absorbs digested fat at the intestinal villi |
What materials from the lymph is returned to the blood? | water, proteins and blood cells |
What are the defense cells within the lymph nodes? | macrophages and lymphocytes |
What are the functions of the spleen? | Filters blood, Destroys worn out blood cells, Forms blood cells in the fetus, Acts as a blood reservoir |
What are peyers patches? | Small accumulations of lymphoid tissues in the wall of the intestines |
What are some key features of the adaptive immunity? | Antigen specific, Systemic (not restricted to initial infection site), and has memory |
What is the main reason our body rejects donor transplants? | It does not recognize the antigens on the cells as self antigens and attacks the tissue |
Where do the B cells become immunocompetent? the T cells? | B cells - bone marrow, T cells - thymus |
What do lymphocytes originate from? | hemocytoblasts in the red bone marrow |
What is the main way cytotoxic T cells kill their target? | Insert a toxic chemical to poke hole in the cell membrane (perforin) |
What do regulatory T cells do? | Release chemicals to suppress the activity of T and B cells and stop the immune response to prevent uncontrolled activity |
What is the main receptor that helps immune cells to "see" inside a cell and recognize antigens? | Major Histocompatibility Complex (MHC) |
What is another term for Major Histocompatibility Complex (MHC)? | HLA (human leukocyte antigen) |
What cells have MHC class I? | All cells |
What does the MHC bind to in a general sense? | TCR (T cell receptor) |
What is the TCR similar to? | similar to the Fab portion of antibodies since it has constant and variable regions and VDJ recombination |
What are the two main subunits on the TCR? | alpha and beta subunits |
What other co-receptors are associated with the TCR? | CD3, CD4 and CD8 |
When a MHC class binds to a TCR, what specificities must be met for successful activation of a T cell? | Must have correct co-receptor (CD4 or CD8, depending on MHC class 1 or 2), and must be specific for the antigen that is presented on the MHC |
What happens if a TCR binds to the wrong MHC class? What happens if it binds to the right MHC class, but it is not specific for that antigen? | 1) T cell dies, 2) T cell lives but is not activated |
MHC class I binds to what cell? | cytotoxic T cell (CD8 co-receptor) |
MHC class II binds to what cell? | helper T cell (CD4 co-receptor) |
What cells have MHC class II? | antigen presenting cells |
What is a autograft? | tissue transplanted from one site to another on the same person |
What is a isograft? | tissue grafts from an identical person (identical twin) |
What is a allograft? | tissue taken from an unrelated person |
What is a xenograft? | tissue taken from a different animal species |
What are the ideal donors? What graft will never be successful? | autografts and isografts are ideal, and xenografts are never successful |
What happens to your immune system from HIV? | HIV attaches to CD4 receptors of T helper cells, eventually causing them to die. Thus, as the T helper cells get too low in numbers to signal the adaptive immune system for efficient killing, the person will eventually die of a secondary infection |
What is phase I of AIDS progression? How long is it? | few weeks to a few years; flu like symptoms, swollen lymph nodes, chills, fever, fatigue, body aches. Virus is multiplying, antibodies are made but ineffective for complete virus removal |
What is phase II of AIDs progression? How long is it? | within six months to 10 years; opportunistic infections present, Helper T cells affected, 5% may not progress to next phase |
What is phase III of AIDs progression? | Helper T cells fall below 200 per cubic millimeter of blood AND the person has an opportunistic infection or type of cancer. May include pneumonia, meningitis, tuberculosis, encephalitis, Kaposi’s sarcoma, and non-Hodgkin’s lymphoma... |
What happens in autoimmune diseases? | The immune system does not distinguish between self and nonself; the body produces antibodies and sensitized T lymphocytes that attack its own tissues |