1. Immune Response

2. Vocabulary Immunology- the study of host defense mechanisms
Immunity- ability of the host to protect itself against foreign organisms. Resistance to disease.
Antigen (Ag)- is a foreign substance that can elicit specific immune response (IR) when is immunogenic
Antibody (Ab)- protein produced by the body’s immune system when it detects harmful substances called antigens
White blood cells (leukocytes)- chief function is to protect the body against microorganisms causing disease and fight infection when it occurs. They are bigger than red blood cells.
Antigen are molecules found on the surface of cells, viruses, fungi, or bacteria. Antibodies are also produced when immune system mistakenly considers healthy tissue a harmful substance (autoimmune disorders). Leukocytes are present in peripheral blood as well as in the lymphatic system

3. Leukocytes (White Blood Cells (WBC))
Protect the body against microorganisms, toxins, & tumor cells.
remove dead cells & debris from body
Complete cells with all organelles
Stained & further identified by
size
shape of the nucleus
presence/absence of granules
colors taken up by their granules

4. Normal Blood Smear
WBCs account for less than 1% of blood’s volume

5. White Blood Cells (WBC)
5 Major types of WBC
Neutrophils
Eosonophils
Basophils
Lymphocytes (T and B Cells)
Monocytes
Divided into two categories
Granuolocytes and Agranuolocytes
Peripheral blood is the flowing, circulating blood of the body. It carries nutrients to all organs and systems of the body. Also carry cellular waste from cells to excretory system.

6. Granuolocytes Neutrophils are the most common WBC in peripheral blood.
Circulate in blood 7-10 hrs before migrating into tissue
Live only a few days (1-2 in tissue)
“front line of innate defense”
1st WBCs to show up at an infection site
Increase in # used as an indicator of infection
Extravasate in inflammation rxn
Active phagocytes
Fungi

7. Granuolocytes Eosonophils Defend the body in parasitic infections
Tapeworms, hookworms, pinworms
Function in phagocytosis
Account for less than 5% of WBC
Involved in allergies
Reduce or control inflammatory response by destroying histamine
Red bi-lobed nucleus with red granules

8. Granuolocytes Basophils Least common WBC in blood Non phagocytic
Function as “sirens” for inflammation and allergy
Produce histamine (a vasodilator) and heparin
Large, histamine containing granules that stain dark purple to blue