NURS 365 NURSING SCIENCE (2025-
2026) IMMUNE SYSTEM STUDY
NOTES (summarized and accurate to
pass) FALL SERIES VIRGINIA
COMMONWEALTH UNIVERSITY
, Introduction to Immunology
What is Immunology?
● Immunology in its most basic form is defined as the study of the body’s defenses
against disease.
General Concepts
*Immune responses aren’t always a good thing*
● Immunity is the ability to resist infection.
● Antigen is any substance capable of causing an immune response.
● Immune system normally responds to run-self antigens, but maintains tolerance
to self-antigens.
● Immune responses are not always beneficial and can cause tissue damage or death
(breakdown in tolerance)
Why Study Immunology?
- We are constantly bombarded with infectious agents but we are seldom sick.
- The immune system is important in a wide variety of non-infectious disease states
as well.
(Interactive defense mechanism, immune system plays a role in non-infectious conditions)
Lymphoid Tissues
● Primary lymphoid organs (yellow) → bone marrow and thymus
● Secondary lymphoid organs (blue) → lymph nodes and spleen
● Lymphatic vessels (lymphatics) —> carry lymph
*Lymphatics work in complementary to the blood vessels*
- Immature lymphocytes migrate through the primary lymphoid tissue (Bone Marrow
S Thymus)
- Bone marrow central lymphoid tissue for B cells
- Thymus central lymphoid tissue for T lymphocytes
- Lymphocytes when they mature they later present in the secondary lymphoid
tissues
Cells of the Immune System
● Have a very specific developmental pattern (all immune cells are identified as CD
markers)
● Have highly specific functions and characteristics
● Can be identified by a specific protein on its cell surface. This is called a Cluster of
Differentiation or CD marker. (serves as identity)
B Cells
● Develop in the Bone Marrow
● Have specific antigen receptor called the B cell receptor (BCR)
2026) IMMUNE SYSTEM STUDY
NOTES (summarized and accurate to
pass) FALL SERIES VIRGINIA
COMMONWEALTH UNIVERSITY
, Introduction to Immunology
What is Immunology?
● Immunology in its most basic form is defined as the study of the body’s defenses
against disease.
General Concepts
*Immune responses aren’t always a good thing*
● Immunity is the ability to resist infection.
● Antigen is any substance capable of causing an immune response.
● Immune system normally responds to run-self antigens, but maintains tolerance
to self-antigens.
● Immune responses are not always beneficial and can cause tissue damage or death
(breakdown in tolerance)
Why Study Immunology?
- We are constantly bombarded with infectious agents but we are seldom sick.
- The immune system is important in a wide variety of non-infectious disease states
as well.
(Interactive defense mechanism, immune system plays a role in non-infectious conditions)
Lymphoid Tissues
● Primary lymphoid organs (yellow) → bone marrow and thymus
● Secondary lymphoid organs (blue) → lymph nodes and spleen
● Lymphatic vessels (lymphatics) —> carry lymph
*Lymphatics work in complementary to the blood vessels*
- Immature lymphocytes migrate through the primary lymphoid tissue (Bone Marrow
S Thymus)
- Bone marrow central lymphoid tissue for B cells
- Thymus central lymphoid tissue for T lymphocytes
- Lymphocytes when they mature they later present in the secondary lymphoid
tissues
Cells of the Immune System
● Have a very specific developmental pattern (all immune cells are identified as CD
markers)
● Have highly specific functions and characteristics
● Can be identified by a specific protein on its cell surface. This is called a Cluster of
Differentiation or CD marker. (serves as identity)
B Cells
● Develop in the Bone Marrow
● Have specific antigen receptor called the B cell receptor (BCR)
