Module 1 2017-01-11 2:37:00 AM
• clear fluid that have leaked out of the capillary walls into interstitial
• They travel to the lymph nodes to be filtered, this is where antigen
specific immunity is generated
• Lymph vessels carry lymph to the heart where it renters the blood
• B cells and T cells are mostly found in the lymph
• Small bean shaped
• Filled with lymphocytes that recognized antigens
Primary Lymph Organs- sites where lymph cells originate(T-cells and B-cells)
Thymus- where T-cells mature
Bone Marrow- origin of all progenitor cells, B-cells mature
Secondary Lymph Organs- lymphocytes interact with one another becoming
more antigen specific
Spleen- filters the blood and eliminates antigens
Lymph Nodes- filters the lymph and eliminates antigens
Mucosal Associated Lymphoid Tissue Module 2 2017-01-11 2:37:00 AM
* the immune system can recognize self and non-self, cells express MHC on
their surface as a marker of “self”. The immune system recognize specific
protein on the surface of foreign antigens.
Steps: pathogen enters body, immune system recognizes, activates effector
cells or eliminate infected cell.
Adaptive immunity: eliminates specific pathogens and provide immunological
memory. Takes a few days. Specific.
humoral mediated- antibodies (made by B-cells)
cell mediated- T-cells
Innate: early defense and alerts adaptive of invasion. Present before the
onset of the infection. Non-specific.
• Physical barriers
• Phagocytic leukocytes
• Dendritic cells
• NK cells
• Plasma proteins Module 1 2017-01-11 2:37:00 AM
*immune cells are made from stem cells in the fetal liver then circulated
through the extracellular fluid.
B-cells- mature in bone marrow
T-cells- mature in thymus
Hematopoeitic stem cells- found
in bone marrow, self renewing,
can give rise to all cells types
within the body (pluripotent).
Can differeinated into 2 types of progenitor cells:
• Myeloid progenitor cells- differentiate into most of the innate
o Monocytes/Macrophage: engulf and kill bacteria. In blood
they are monocytes but as they enter damaged tissue they
o Neutrophil: mature in bone marrow and migrate to mature
tissue, lifespan of a few days. Phagocytes containting lytic
enzymes like peroxidase stores in granules which help in
o Basophil: Non-phagocytic granulocytes, release chemical
mediators from their granules. Major role in allergic reactions.
o Eosinphil: Macrophages, secrete contents of their granules to
damage parasites membrane.
• Lymphoid progenitor cells- defferinated into cells of the adaptive
immune system. o B Lymphocytes (humoral): “native” until coming into contact