Term
| What is the most important tissue in the immune system? Located? |
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Definition
Lymphoid tissue found in 2 general locations:
1. digestive, urinary, respiratory, and reproductive tracts
2. Lymphoid organs |
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Term
| Lymphoid tissue found in digestive, urinary, respiratory, and reproductive tracts |
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Definition
Mucosa- associtated lymphoid tissues (MALT)
-GALT, gut associated
-BALT, bronchus associated |
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Term
| Lympoid tissue found in organs includes: |
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Definition
lymph nodes, tonisils, spleen, appendix
They are designed to gather and destroy infectious microorganisms |
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Term
| What type of tissue is Lymphoid tissue? |
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Definition
loose CT
-reticular fibers (from fibroblasts) support cells:
Lymphocytes, both effector and memory cells
dendritic cells
macrophages
Immune cells found in most loose CT in body, large amounts in lymphoid tissue |
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Term
| What are lymphoid nodules? |
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Definition
after activation, B cells from distinctive sperical structures in lymphoid tissue- nodules
Center of nodules= germinal centers, rapidly proliferating B cells |
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Term
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Definition
| no distinctive morphology |
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Term
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Definition
immature lymphocytes develop into T lymphocytes, part of mediastinum, superior to heart
Secretes thymic hormons
Most active in childhood, functional tissue atrophies with age
Many lubule (cauliflower florets)
Composed of cortex and medulla
immature T cells enter tru arteries and exit from capillaries and ener lymphoid tissue
mature T cells re-enter capillaries and leave via viens |
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Term
| How doe T cells travel to from thymus |
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Definition
immature T cells enter tru arteries and exit from capillaries and ener lymphoid tissue
mature T cells re-enter capillaries and leave via viens |
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Term
| In the thymus, what is positive selection in cortex? |
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Definition
| survival of T cells that can recognize own bodies infected cells, must eventually be able to recognize and destroy |
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Term
| What is negative selection in medulla? |
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Definition
T cells that bind too strongly to own cells are eliminated
Minimizes autoimmune disease |
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Term
| What are Lymph nodes, what are thee functions? |
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Definition
Dense CT capsule
-most antigenic challenges occur here
-antigens destroyed- and activate B and T lymphocytes
-Lymph percolates through lymph sinuses (afferent/effent vessels)
-Cortex and medulla
-Sinuses throughout and between lmph nodules containing lympoid nodules (follicles) of B cells; T cells scattered |
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Term
| What is the largest lymphoid orgam? |
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Definition
| Spleen, dense CT capsule that has partitions of CT= trabeculae |
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Term
| What is the function of spleen? |
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Definition
blood cleanser
two main functions:
1. removal of blood bourne anigens
2. removal and destruction of old/defective blood cells
Sit of hematopoiesis in fetus
Splenic artery sends branches into trabeculae and becomes central arteries (surrounded by lymphoid tissue) |
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Term
| What is white pulp in the spleen? |
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Definition
| thick sleeve of lymphoid tissue surrounds central arteries |
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Term
| What is red pulp in spleen? |
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Definition
surrounds white pulp
composed of:
1. sinusoids
2. splenic cords- surronds sinusoids
-reticular CT, Blood cells of all types including Red, many macrophages |
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Term
| What is the simplest lymphoid organ? |
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Definition
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Term
| Describe the 4 groups of tonsils: |
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Definition
1. Palatine: posterior-lateral oral cavity
2. Lingual: Base of tongue
3. Pharyngeal: posterior/superior nasopharynx (aka adenoids)
4. Tubal tonsils: lateral nasopharynx |
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Term
Tonsils are arranged -- to remove--
In -- consist of -- |
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Definition
ring to gather and remove pathogens
CT under epithelium, consist of MALT (lympoid nodules) |
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Term
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Definition
in walls of intestines GALT- larege lymphoid nodules to fight invading bacteria in gut
Generate a wide variety of lyphocytes
-aggregated lymphoid nodules (peyer's patches) distal part of small intestine
Appendix-tubular offshoot of the cecum |
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Term
| What are the disorders of the immune system? |
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Definition
1. mononucleosis- viral disease caused by epstein-barr virus (attacks B lymphocytes)
2. Hodgkins disease0 malignancy of lymph nodes
3. Non-hodgkin's lymphoma- uncontrolled multiplication and metastasis of undifferentiated lymphocytes |
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