Chapter 12: Host Defenses Innate Immunity- Part 1 Flashcards
Two types of host defenses
Innate (nonspecific)
Acquired (specific)
Antigen
Anything that solicits an immune response
A healthy, functioning immune system is responsible for..
Surveillance of the body
Recognition of foreign material
Destruction of entities deemed to be foreign
Innate immunity
Things that are always present, nonspecific
How does innate immunity behave?
Behaves the same way no matter what is encountered
What is the innate immunity made up of?
Multiple components that all help to recognize antigen
The ability to recognize antigen is based on the capability to what?
Differentiate self from nonself
First line of defense
Inborn, nonspecific defenses
3 types of First Line of Defense
Physical
Chemical
Genetic
What do first line defenses do?
Impede the entry of microbes and other foreign agents, living or non-living
Physical barriers: skin
- Stratum corneum
- Shedding
Physical barriers: mucous membranes
- Shedding of cells
- Mucous
- Cilia in some areas (lungs)
Physical barriers: normal flora
- Essential to function of many organs
- Can help protect against pathogens
- Microbial warfare
Chemical barriers
examples
Sebum Sweat Tears Saliva Stomach acid Intestinal enzymes Other bodily fluids
Chemical barriers: sweat
pH
Flushing
Chemical barriers: tears
Flushing action Contains lysozyme (attacks cell wall of bacteria, also in vaginal secretions)
Chemical barriers: saliva
Lysozyme
Second line of defense
Generalized and nonspecific defenses that support and interact with specific immune responses
4 types of second-line defenses
Phagocytosis (cells)
Inflammation
Fever
Antimicrobial proteins
Hematopoiesis
Production of blood cells
Where does hematopoiesis take place?
In the red bone marrow
White blood cells (leukocytes) are programmed to develop into…
Several secondary cell lines
Leukocytes are primarily responsible for _______ ________
Immune function
Two lineages in hematopoiesis
Myeloid
Lymphoid
The lymphoid stem cell can differentiate into what cells?
Lymphoblasts then lymphocytes
OR
Natural killer cells
Lymphocytes
Primary cells involved in specific immune reactions to foreign matter
Types of lymphocytes
T cells
B cells
T cells
Perform a number of specific cellular immune responses such as assisting B cells and killing foreign cells (cell-mediated immunity)
B cells
Differentiate into plasma cells and form antibodies (humoral immunity)
Natural killer cells
Related to T cells but display no antigen specificity, active against cancerous and virally infected cells
What tells cells to go down the myeloid vs lymphoid lineage?
Cytokines
Types of cells in the myeloid lineage
RBCs Platelets (from megakaryocytes) Neutrophils Basophils Eosinophils Monocytes Macrophages Dendritic cells Mast cells
Granulocytes
Neutrophils
Basophils
Eosinophils
Agranulocytes
Monocytes
T cells
B cells
Professional phagocytes
Neutrophils
Monocytes
Macrophages
~Dendritic cells~(usually not one of first to respond)
General activities of phagocytes are..
- Survey the tissue compartments and discover microbes, particulate matter and injured or dead cells
- Ingest and eliminate materials
