Unit 2 : The Innate Immune System Flashcards
Granulocytes
- Neutrophils
- Eosinophils
- Basophils
Agranulocytes
- Monocytes 3-8% 7.5 um
- Lymphocytes 20-25% 7.5um
Neutrophils
Engulf microorganisms, abnormal cells, and foreign particles by phagocytosis
Eosinophil
Secrete enzymes that kill parasites; contribute to tissue damage in allergic reactions
Basophils / Mast Cell
Secrete chemical mediators of inflammation and allergic reactions
Monocyte / Macrophage
Secretes cytokines; engulf microorganisms by phagocytosis
Lymphocytes
- Plasma cells (mature form of B cells) secrete antibodies
- helper T cells secrete cytokines that activate multiple cell types: cytotoxic
- T cells secrete factors that lead to death of tumor cells
- null cells called KILLER CELLS secrete factors that lead to the death of infected cells and tumor cells
B Cells
Associated w/ antibodies
T Cells
2 types
1) helper t cell = produce chemicals that help all other immune cells
2) cytotoxic T cell= directly damages foreign cells
Central Lymphoid Tissue
Bone marrow & thymus
Peripheral Lymphoid Tissue
Spleen, lymph nodes, tonsils, adenoids, appendix, and peyers patches
Functions:
- trap microorganisms & foreign particles
- expose them to leukocytes in high concentrations
Type of lymphocyte matures in the Thymus
T- Lymphocytes
(migrate from bone marrow to thymus and develop maturity )
Skin
1) barrier
2) secretions
- anti microbial peptides (aka defensins)
-lysozyme (destroy cell walls)
Muco- ciliary Escalator
-covers most of bronchi, bronchioles & nose
- cilia continually beating, pushing mucus up and out into throat
Lacrimal Apparatus
Group of structures that produce & drain tears
Steps of Phagocytosis
1) chemotaxis
2) adherence
3) ingestion
4) killing
5) elimination
Chemotaxis
- phagocyte moves toward pathogen
Adherence
Phagocyte sticks to the pathogen
Ingestion
Phagocytes internalizes the pathogen
- pathogen is brought into a vacuole called a phagosome
Killing
- Phagocyte kills pathogen
-phagosome fuses w/ lysosome to form a phagolysosome - enzyme destroy the pathogen
Elimination
- phagocyte gets rid of pathogen remnants
*phagolysome containing destroyed microorganisms deposits the contents to the outside of cell via exocytosis *
Types of cells that can carry out phagocytosis
1) neutrophils
2) macrophages
3) dendritic cells
eosinophils are also capable of phagocytosis but not their primary activity
Main job of eosinophils?
Defend us from worms
Natural killer cells
Eosinophils
What do interferons do?
Induce virus resistance in neighboring cells
What cells make infernos alpha, beta and gamma
Viral nucleic acid
What is complement?
Group of serum proteins that activate one another to destroy invading microorganisms
What 3 ways is complement activated?
Classical, alternative, and lectin
Complement C3 activation can lead to what?
-cell lysis
-inflammation
-opsonization
What does lysozyme do?
Breaks bonds between NAG and NAM subunits of peptidoglycan in the cell wall
(Destroy cell wall)
Where can a lysozyme be found?
In secretions
What are the 4 cardinal signs of inflammation?
1) redness
2) heat
3) edema
4) pain
