Immunology part 1 Flashcards
3 key properties of a NORMAL immune system
highly diverse group of antigen receptors
immune memory
immunologic tolerance
antigen receptors allow
for recognition of plethora of pathogens
immune memory allows for
rapid recall of immune responses
immunologic tolerance prevents
immune damage to normal self tissue
A pathogen is
any organism that has the potential to cause disease
what are the three roles of the immune system
- defend against invasion
- distinguish between self and invader
- defend against abnormal cells/molecule formation in the body (neutralize anything that does get in)
immunity is
our bodies way of defending against pathogens and foreign substances that cause disease
immune system is
the collection of cells, tissues, and molecules that mediate the resistance efforts.
immune response
coordinated reactions of those cells and molecules against infectious microorganisms
The most important function in our immune system is
defending against infection by preventing infection and/or eliminating established infections
What is innate/natural immunity and what does it include
The 1st line of immune defense. includes skin and epithelial layers which physically separate the body from external environment.
What is adaptive/acquired immunity and what does it include
2nd line of immune defense, found only in vertebrates, adaptive immunity/antigen specific immunity. (dependent on influences from the innate immune system
What is the initial protection in the body that acts immediatly
innate immunity
what is the slower specialized response in the body
adaptive immunity
Describe innate immunity in terms of:
response time
diversity
microbe recognition
principle immune cells involved
memory
response time: immediate (minutes to hours)
diversity: limited number of antigens recognized and limited number of groups of microbes identified.
Microbe Recognition: general patterns on microbes, nonspecific
principle immune cells involved: granulocytes, monocytes/macrophages, natural killer cells and dendritic cells.
memory: no memory, responds the same way to repeat encounters with the same pathogen
Describe innate immunity in terms of:
response time
diversity
microbe recognition
principle immune cells involved
memory
response time: Delayed (takes days to weeks)
diversity: large number of highly selective antigens recognized
microbe recognition: specific to individual microbes and antigens
principle immune cells involved: B lymphocytes, T lymphocytes, dendritic cells, natural killer cells.
memory: yes, responds more effectively after each encounter with the same pathogen.
Where do the cells involved in immunity come from?
bone marrow and lymph tissue
Epithelial barriers:
Where are they found (give examples)
what are the subcategories
what do the subcategories consist of
found in all portals of entry into the body such as skin, respiratory, GI and urogenital tracts
subcategories are mechanical/physical barriers, chemical barriers, and microbiological/cellular barriers.
Mechanical/physical barriers = flow of fluids (persperation, mucus, saliva, urine, tears
chemical = sebum, enzymes, lysozymes in nasal secretions, acidity in vaginal secretions, and lysozymes in tears, antimicrobial peptides.
microbiological/cellular = normal flora of skin, GI tract, respiratory tract, urogenital tract and eyes.
what are the cells of the innate immune system and what do they stem from
all immune cells stem from stem cells and innate cells are divided into a subgroup called “myeloid progenitors”. These are mostly granulocytes (included neutrophils, eosinophils, basophils and mast cells) as well as monocytes (which stem into dendritic cells and macrophages)
Monocytes
granulocyte or agranulocyte
what do they do
facts (6 of them total)
Agranulocytes
- circulate in the blood
-largest WBCs
- precursors of tissue macrophages (turn into macrophages when they leave blood and enter tissues)
- when they enter tissues, they become macrophages and are sometimes given special names depending on their location (ex. cilia are macrophages of the lungs)
- monocytes may also mature into dendritic cells.
Macrophages
Agranulocytes
-monocyte-macrophages are the first phagocyte microbes encounter when entering the host
-essential for clearing bacteria that gets past epithelial barrier in multiple organs.
-perform phagocytosis to get rid of microbes
-produce cytokines that help initiate inflammation and recruitment of other cells to the tissue site.
-present antigens to T lymphocytes
-non-immune function is to act as garbage disposals.
what is the first phagocyte that microbes encounter when entering a host
monocyte/macrophages.
Dendritic cells
-reside in body’s tissues (skin, mucosal membranes)
-serve as cellular messengers that initiate adaptive responses
-present antigens to T lymphocytes
Where did dendritic cells get their names
named due to thin projections on their surface
