PATHO EXAM 4: IMMUNOLOGY 2025/2026
QUESTIONS WITH ANSWERS GRADED A+
Immunology - The study of physiologic mechanisms that allow the body to recognize materials
as foreign and to neutralize or eliminate them
Vertebrate Immune System Components - Organs
Tissues
Cells
Proteins
Primary Organs - bone marrow and thymus
Secondary Organs - lymph nodes, spleen, tonsils, adenoids, appendix
Tissues - Peyer's patches
In dermis of intestines
Concentrated area of lymphocytes
1st line of defense in intestines
Cells - Leukocytes, lymphocytes (natural killer cells), other phagocytes
Proteins - Major histocompatibility complex
Cell surface molecules
Bind to peptide fragments derived from pathogens and display on cell surface of various immune
cells to be recognized by various T cells for phagocytosis
Bone Marrow - Where all immune cells are created
Granulocytes (Neutrophils, Eosinophils, Basophils)
Natural Killer T cells
B cells
,RBCs
Platelets
Thymus - Blood marrow sends immature t cells to thymus
Thymus matures the T lymphocytes
Release mature T cells into blood
Where do mature T-cells go? - from Thymus to lymph nodes and spleen
Spleen - filters and destroys old RBCs
Immune role = filters blood antigens
Macrophages bring in antigens through blood
Spleen T-cells destroy Ag
Spleen B cells produce Ab (antibody)
Self-tolerance - The body's immune defenses (phagocytes and antibodies) do not attack tissues
that carry a self marker
Antigen (Ag) - any substance capable of triggering an immune response
Epitopes - a site on the antigen that the Ab identifies with and specifically binds to
Antigenic determinant
displays foreign-ness
Molecule subunits protrude from its surface
Ag's may have 100s
Auto-immune diseases - Epitopes may be misinterpreted and self is identified as non-self
body cannot differentiate
Allergies - a relatively harmless substance (pollen, cat hair) provokes the immune system to set
off an allergic response
, Self Markers - Proteins present on the surface of all body cell membranes
Genetically determined
Unique as a fingerprint
Major Histocompatibility Complex Proteins - Originally discovered on leukocytes in man and
were called Human Leukocytic Ag
Discovered during transplantation studies
Cause strong immune response and rejection of organ
Determines which antigens an individual responds to and how strongly
Triggers T cell activation
Allows the immune system cells to recognize and communicate with one another
Can increase auto-immune diseases
Pluripotent hemopoietic stem cell (PHSC) - In bone marrow
majority of these stem cells become mature blood cells
some cells will remain in the bone marrow
numbers decrease with age
What controls growth and reproduction of stem cells? - Growth inducer proteins
Differentiation inducer proteins
Stem cells can differentiate into ...? (2 main choices) - Lymphocytes
Granulocytes
Granulocytes - a WBC with granules in cytoplasm
Neutrophil
Eosinophil
Basophil
Types of Monocytes - Dendritic cell
QUESTIONS WITH ANSWERS GRADED A+
Immunology - The study of physiologic mechanisms that allow the body to recognize materials
as foreign and to neutralize or eliminate them
Vertebrate Immune System Components - Organs
Tissues
Cells
Proteins
Primary Organs - bone marrow and thymus
Secondary Organs - lymph nodes, spleen, tonsils, adenoids, appendix
Tissues - Peyer's patches
In dermis of intestines
Concentrated area of lymphocytes
1st line of defense in intestines
Cells - Leukocytes, lymphocytes (natural killer cells), other phagocytes
Proteins - Major histocompatibility complex
Cell surface molecules
Bind to peptide fragments derived from pathogens and display on cell surface of various immune
cells to be recognized by various T cells for phagocytosis
Bone Marrow - Where all immune cells are created
Granulocytes (Neutrophils, Eosinophils, Basophils)
Natural Killer T cells
B cells
,RBCs
Platelets
Thymus - Blood marrow sends immature t cells to thymus
Thymus matures the T lymphocytes
Release mature T cells into blood
Where do mature T-cells go? - from Thymus to lymph nodes and spleen
Spleen - filters and destroys old RBCs
Immune role = filters blood antigens
Macrophages bring in antigens through blood
Spleen T-cells destroy Ag
Spleen B cells produce Ab (antibody)
Self-tolerance - The body's immune defenses (phagocytes and antibodies) do not attack tissues
that carry a self marker
Antigen (Ag) - any substance capable of triggering an immune response
Epitopes - a site on the antigen that the Ab identifies with and specifically binds to
Antigenic determinant
displays foreign-ness
Molecule subunits protrude from its surface
Ag's may have 100s
Auto-immune diseases - Epitopes may be misinterpreted and self is identified as non-self
body cannot differentiate
Allergies - a relatively harmless substance (pollen, cat hair) provokes the immune system to set
off an allergic response
, Self Markers - Proteins present on the surface of all body cell membranes
Genetically determined
Unique as a fingerprint
Major Histocompatibility Complex Proteins - Originally discovered on leukocytes in man and
were called Human Leukocytic Ag
Discovered during transplantation studies
Cause strong immune response and rejection of organ
Determines which antigens an individual responds to and how strongly
Triggers T cell activation
Allows the immune system cells to recognize and communicate with one another
Can increase auto-immune diseases
Pluripotent hemopoietic stem cell (PHSC) - In bone marrow
majority of these stem cells become mature blood cells
some cells will remain in the bone marrow
numbers decrease with age
What controls growth and reproduction of stem cells? - Growth inducer proteins
Differentiation inducer proteins
Stem cells can differentiate into ...? (2 main choices) - Lymphocytes
Granulocytes
Granulocytes - a WBC with granules in cytoplasm
Neutrophil
Eosinophil
Basophil
Types of Monocytes - Dendritic cell
