Cells and Organs of the Immune System Flashcards
What are the 3 lines of defense?
- Skin, MM, chemicals (innate)
- Phagocytosis, complement, interferon, inflammation, fever (innate)
- Lymphocytes, antibodies (adaptive)
Characteristics of granulocytes
WBC with cytoplasmic granules
produced in bone marrow
classified based on H&E stain
Types of granulocytes
Basophils (granules stain dark blue)
Eosinophils (granules stain red)
Neutrophils (granules stain neutral pink)
Characteristics of basophils
Defend against parasites
Allergic/inflammatory reactions
Toxic granules
Express adhesion molecules (LFA-1, Mac-1, CD44)
Characteristics of eosinophils
Defend against parasites - kill Ab coated parasites
Allergic reactions
Respond to chemokines secreted by neutrophils/lymphocytes
Toxic granules
Characteristics of neutrophils
Most numerous innate immune cell Band-shaped nucleus when immature Segmented nucleus when mature Circulate in blood Phagocytosis and degradation
What can a high ANC (absolute neutrophil count) indicate?
*Neutrophilia
Kidney failure or bacterial infection
What can a low ANC indicate?
*Neutropenia
Leukemia or bone marrow damage
Similar to basophilic leukocytes, _____ are generated in the bone marrow and have CD34+ precursor cells.
Mast cells
Two types of mast cells
CT mast cell - local allergic reactions
Mucosal - In areas of body exposed to external env (Lungs, digestive tract, mouth, nose)
Activated function of mast cells
Release granules containing histamine - mediate allergic reactions
Defend against parasites
Monocytes vs macrophages location
Monocytes - in blood
Macrophages - in tissue
Function of macrophages/monocytes
Phagocytosis and Ag presentation
Examples of tissue-specific macrophages
Bone - osteoclasts
Nervous - microglial cells
Liver - Kupffer cells
Histiocytes
Do macrophages always create an immune response while functional?
No, they also perform housekeeping functions such as recycling dead RBCs
Which cells recognize and kill virus-infected or tumor cells, and have features of both innate and adaptive immunity?
Natural Killer cells
What do the granules of the natural killer cells do?
Proteins form holes in the target cell and cause apoptosis
How do natural killer cells regulate the immune response?
Activate dendritic cells, T-cells, and macrophages
______ are specialized sentinel cells that move around and respond to their environment, presenting Ag to T cells.
Dendritic cells
Which immune cells promote self-tolerance?
Dendritic cells
What is special about plasmacytoid dendritic cells (pDCs)?
Have the ability to secrete large amounts of type 1 interferons upon activation through TLR7 and TLR9
Which lymphocytes are part of the humoral immune response, mature in the bone marrow, bind Ag and generate Ab?
B lymphocytes