Immune System Flashcards
1
Q
- transport oxygen (to tissues) and CO2 (away from tissues)
- help buffer pH
- most abundant
A
erythrocytes
2
Q
- pinched-off cytoplasmic fragments of specialized bone marrow cells involved in blood clotting
- adhere to collagen fibers exposed by damage to endothelial cells of blood vessels
- release factors that make its cells more “sticky” and convert the plasmid protein prothrombin to thrombin, which (eventually) helps convert the plasmid factor fibrinogen to fibrin
A
platelets
3
Q
neutrophils, basophils, eosinophils
A
granulocytes (aka polymorphonuclear leukocytes)
4
Q
- numerous lysosomes and secretory vesicles
- phagocytic
- attracted to and enter infected tissues
- especially effective against bacteria and fungi
- release neutrophil extracellular traps (NETs)
- one of the two main “professional phagocytes”
A
neutrophils
5
Q
- synthesize and secrete histamine
- arterioles dilate and capillary permeability increases
- leads to edema, redness, and heat
- secrete heparin, which modulates clotting
- similar to Mast cells found in connective tissue
A
basophils
6
Q
- low phagocytic activity but critical to defense against multicellular parasites
- secretes toxic proteins
A
eosinophils
7
Q
monocytes and macrophages
A
agranulocytes (aka mononuclear leukocytes)
8
Q
- only circulate for a few hours and then migrate into tissues and transform into macrophages
A
monocytes
9
Q
- large, long-lived cells
- phagocytic via pseudopodia and phagosomes
- some migrate throughout body while others reside in various organs and tissues (i.e. spleen and lymph nodes)
- one of two main “professional phagocytes”
- use nitric oxide and enzymes like lysozyme
- important antigen-presenting cell, esp. during secondary immune responses
A
macrophages
10
Q
a major antigen-presenting cell type, esp. during primary immune response; ex: Langerhans cells in skin
A
dendritic cells
11
Q
NK cells, B cells, T cells, CD8+ cells, CD4+ cells
A
lymphocytes
12
Q
- activated by alpha (secreted by virus-infected leukocytes) and beta (secreted by virus-infected fibroblasts or epithelial cells) interferons
- produce gamma interferon (as do activated T-cells), which helps activate macrophages
- kill by apoptosis (cytotoxic, but not by phagocytosis)
- part of innate immune system
- especially effective against viral-infected cells and cancer cells
A
natural killer cells
13
Q
- develop in the bone marrow
- epitope-specific Y-shaped receptors (known as B-cell receptors)
- recognize intact, native state epitopes
- secrete antibodies
- after clonal selection, they form short-lived effector cells (aka plasma cells) and long-lived memory B-cells
- antibodies include IgM, IgG, IgA, IgE, and IgD
A
B cells
14
Q
- develop in the thymus
- epitope-specific I-shaped receptors (known as T-cell receptors)
- recognize small fragments of antigens that are bound to normal cell-surface proteins called major histocompatibility complex (MHC) proteins
- known for antigen-presentation
- after clonal selection, T cells form short-lived effector cells (activated helper T cells and active cytotoxic T cells) and long-lived memory helper T-cells and memory cytotoxic cells
A
T cells
15
Q
- cytotoxic T-cells
- recognize Class I MHC, which display antigen fragments that were synthesized within the cell due to infection or a cancerous state (Class I MHC molecules are found on almost all nucleated cells)
- releases perforin molecules, which form pores, and proteolytic enzymes (granzymes) taken up by endocytosis; this leads to apoptosis
A
CD8+ cells (binds MHC 1)
