Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medical Microbiology I > Elements of Host Protective Response (Part 2) > Flashcards

Elements of Host Protective Response (Part 2) Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards USMLE® Step 1 flashcards
1
Q

Phagocytic cells

A
  • Neutrophils
  • Monocytes
  • Macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Phagocyte types/characteristics

A
  • Myeloid progenitor lineage
  • Granulocyte (monocyte CFU)
  • Polymorphonuclear leukocytes
  • Mononuclear
  • Dendritic Cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Phagocytosis definition

A
  • Process by which certain cells of the innate immune system (neutrophils & macrophages) engulf large particles, such as intact microbe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Process of phagocytosis

A
  • Cell surrounds the particles with extensions of its plasma membrane
  • Leads to formation of a intracellular vesicle called a phagosome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chemotaxis

A
  • Movement of a cell directed by a chemical concentration gradient
  • Movement of leukocytes into various tissues directed by gradients of chemokines
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cyotkines

A
  • Secreted proteins that function as mediators of immune and inflammatory reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In innate immune responses, cytokines are produced by

A
  • Macrophages

- Natural killer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In adaptive immune responses, cytokines are produced by

A
  • Mainly T lymphocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Chemokines

A
  • A large family of structurally homologous, low-molecular-weight cytokines
  • Stimulate leukocyte movement
  • Regulate migration of leukocytes from the blood to tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Polymorphonuclear leukocytes (neutrophils) important features

A
  • Short-lived
  • Comprise 50% to 70% of circulating WBCs
  • Primary phagocytic defense against bacterial infection
  • Major component of the inflammatory response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Polymorphonuclear leukocytes (neutrophils) physical characteristics

A
  • 9 to 14 μm in diameter
  • Lack mitochondria
  • Granulated cytoplasm in which granules stain with both acidic and basic stains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Polymorphonuclear leukocytes (neutrophils) nucleus

A
  • Multilobed nucleus

- “Segmented” at terminal differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Polymorphonuclear leukocytes (neutrophils) response to infection

A
  • Leave the bloodstream
  • Concentrate at the site of infection in response to chemotactic factors
  • Increase in number in the peripheral blood and include precursor forms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Bone marrow in response to infection

A
  • Production of polymorphonuclear leukocytes (neutrophils) from the bone marrow increases rapidly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Polymorphonuclear leukocyte (neutrophil) production is stimulated by

A
  • Cytokines that are secreted by many cell types in response to infection
  • Act on bone marrow stem cells to stimulate proliferation & maturation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Band forms

A
  • Precursors of polymorphonuclear leukocytes (neutrophils)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Left shift with an increase in bands versus segs

A
  • Increase in band forms in blood count of polymorphonuclear leukocytes (rather than differentiated forms)
  • Major indicator of infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Polymorphonuclear leukocytes (neutrophils) ingest

A
  • Microbes in the circulation

- Enter extravascular tissue at sites of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Polymorphonuclear leukocytes (neutrophils) ingest bacteria by

A
  • Phagocytosis
  • Expose the bacteria to antibacterial substances and enzymes contained in primary (azurophilic) and secondary (specific) granules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Azurophilic granules are enzymes such as

A
  • Myeloperoxidase
  • β-glucuronidase
  • Elastase
  • Cathepsin G
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Specific granules (polymorphonuclear leukocytes)

A
  • Lysozyme

- Lactoferrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Lifespan of polymorphonuclear leukocytes (neutrophils)

A
  • Cells die after a few hours

- Dead neutrophils are the major component of pus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Eosinophils

A
  • Granulocyte of myeloid lineage
  • Heavily granulated (11 to 15)
  • Phagocytic, motile, and granulated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Eosinophil nucleus

A
  • Bilobed nucleus

- Stains with the acid dye eosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Eosinophil granules contain

A
  • Acid phosphatase
  • Peroxidase
  • Eosinophilic basic proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Role of eosinophils

A
  • Defense against parasitic infections

- Eosinophilic basic proteins are toxic to many parasites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Features/functions of basophils

A
  • NOT phagocytic
  • Release the contents of their granules during allergic responses
  • Similar chemical mediators as mast cells
  • Contribute to immediate hypersensitivity reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Myeloid cells

A
  • Differentiate from myeloid progenitor

- Part of the mononuclear phagocyte system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mononuclear phagocyte system consists of

A
  • Monocytes in the blood

- Cells derived from monocytes in tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Different cytokines or tissue environments promote myeloid stem cells and monocytes to

A
  • Differentiate into the various macrophages and dendritic cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

In the lungs, myeloid stem cells and monocytes differentiate into

A
  • Macrophages

- Alveolar macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In the liver, myeloid stem cells and monocytes differentiate into

A
  • Kupffer cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

In the kidneys, myeloid stem cells and monocytes differentiate into

A
  • Intraglomerular mesangial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In connective tissues, myeloid stem cells and monocytes differentiate into

A
  • Histiocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

In bone and joints, myeloid stem cells and monocytes differentiate into

A
  • Osteoclasts

- Synovial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In the brain, myeloid stem cells and monocytes differentiate into

A
  • Microglial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Characteristics of monocytes

A
  • 10 to 18 μm in diameter
  • Single-lobed, kidney bean-shaped nucleus
  • Represent 3% to 8% of peripheral blood leukocytes
  • Less abundant than neutrophils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Monocyte functions

A
  • Follow neutrophils as an early cellular component of inflammation
  • Ingest microbes in the blood and tissues
  • Unlike neutrophils, when entering extravascular tissues they survive for a longer time & further differentiate into macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Characteristics of macrophages

A
  • Long-lived cells that are phagocytic
  • Contain lysosomes
  • Unlike neutrophils, have mitochondria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Main functions of macrophages

A
  • Phagocytosis
  • Antigen presentation to T cells to initiate specific immune responses
  • Secretion of cytokines to activate & promote innate immune responses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Macrophages express cell surface receptors for

A
  • Fc portion of immunoglobulin (Ig) G

- C3b product of the complement cascade (CR1, CR3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Macrophage receptors facilitate

A
  • Phagocytosis of antigen, bacteria, or viruses coated with their respective proteins (IgG, CR1, CR3)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Pattern-recognition receptors of macrophages

A
  • Recognize pathogen-associated molecular patterns

- Activate protective responses

44
Q

Macrophages expresses the class II MHC antigen

A
  • Allows these cells to present antigen to CD4 helper T cells to expand the immune response
45
Q

Macrophages secrete

A
  • Interleukin-1
  • Interleukin-6
  • Tumor necrosis factor
  • Interleukin-12, etc.
  • Stimulates immune & inflammatory responses (such as that seen in fever)
46
Q

Macrophages respond to interferon-γ

A
  • T-cell derived cytokine that activates macrophages
47
Q

Activated macrophages

A
  • Enhanced phagocytic, killing, and antigen-presenting capabilities
48
Q

Macrophages function as receptors for

A
  • Bacterial components, antibodies, complement
49
Q

Macrophages promote

A
  • Activation & hagocytosis of antigen
50
Q

Macrophage receptors promote

A
  • Antigen presentation

- Activation of T-cells

51
Q

Mononuclear phagocytes arise from

A
  • Precursors in the bone marrow
  • Circulating blood stage is the monocyte
  • Phagocytic vacuoles and lysosomes
52
Q

In the tissues, mononuclear phagocytes become

A
  • Macrophages
  • May be activated by microbes
  • May differentiate into specialized forms that are resident in different tissues
53
Q

The electron micrograph of a portion of an activated macrophage shows

A
  • Numerous phagocytic vacuoles

- Cytoplasmic organelles

54
Q

Dendritic cells

A
  • Myeloid and lymphoid origins
  • Octopus-like tendrils
  • Professional Antigen Presenting Cells (APCs) that can also produce cytokines
  • Important bridge between innate and adaptive immunity
55
Q

Types of dendritic cells and where they are found

A
  • Langerhans cells in the skin
  • Dermal interstitial cells
  • Splenic marginal dendritic cells
  • Dendritic cells in the liver, thymus and germinal centers of the lymph nodes
56
Q

Plasmacytoid dendritic cells

A
  • Present in blood

- Produce large amounts of interferon alpha & cytokines in response to viral & other infections

57
Q

Follicular dendritic cells

A
  • Present in lymph nodes & spleen
  • Not hematopoietic in origin
  • Have tendrils and a “sticky” surface to concentrate & present antigens to B cells
58
Q

Immature dendritic cells

A
  • Capture and phagocytose antigen efficiently
59
Q

Main functions of immature dendritic cells

A
  • Release cytokines to activate and steer the subsequent immune response, and then mature into dendritic cells
  • Move to lymph node regions rich in T cells to present antigen on class I and class II MHC antigens
60
Q

Dendritic cells are the only antigen-presenting cell that can

A
  • Initiate an immune response with a naïve T lymphocyte and also determine the type of response
61
Q

Lymphocytes differentiate from

A
  • Lymphoid progenitor cells
62
Q

Physical characteristics of lymphocytes

A
  • 6 to 10 μm in diameter
  • Smaller than leukocytes
  • Large nucleus and smaller, agranular cytoplasm
63
Q

2 major classes of lymphocytes

A
  • B cells

- T cells

64
Q

B and T cells are indistinguishable by

A
  • Morphologic features

- Basis of function and surface markers

65
Q

Natural killer (NK) cells

A
  • Lymphoid cells that are not B or T cells (non-B/non-T cells, or null cells)
  • Large, granular lymphocytes (LGLs)
66
Q

Primary function of B cells

A
  • Make antibodies
67
Q

General functions of B cells

A
  • Internalize antigen
  • Process the antigen
  • Present the antigen to T cells to expand the immune response
68
Q

B cells can be identified by the presence of

A
  • Immunoglobulins
  • Class II MHC molecules
  • Receptors for the C3b and C3d products of the complement cascade (CR1, CR2) on their cell surfaces
69
Q

The B-cell name is derived from

A
  • Site of differentiation in birds

- The bursa of Fabricius and the bone marrow of mammals

70
Q

B-cell differentiation also takes place in fetal

A
  • Liver & spleen
71
Q

Activated B cells either develop into

A

M-emory cells (express the CD45RO cell surface marker)

- Circulate until activated by specific antigen, or terminally differentiate into plasma cells

72
Q

Plasma cells

A
  • Small nuclei
  • Large cytoplasm
  • Producers of antibody
73
Q

T cells acquired their name because

A
  • They develop in the thymus
74
Q

Two major functions of T cells in response to foreign antigen

A
  • Control, suppress (when necessary), and activate immune & inflammatory responses by cell-cell interactions & by releasing cytokines
  • Directly kill virally infected cells, foreign cells (tissue grafts), and tumors
75
Q

T cell content

A
  • Make up 60% to 80% of peripheral blood lymphocytes
76
Q

T cells were initially distinguished from B cells on the basis of

A
  • Their ability to bind and surround themselves with sheep erythrocytes through the CD2 molecule (forming rosettes)
77
Q

All T cells express

A
  • Antigen-binding T-cell receptor (TCR) that resembles but differs from antibody
  • CD2- and CD3-associated proteins on their cell surface
78
Q

T cells are divided into 3 major groups on the basis of

A
  • Type of TCR
  • Cell surface expression of two proteins (CD4 and CD8)
  • Most lymphocytes express the αβ TCR
79
Q

CD4-expressing T cells are primarily

A
  • Cytokine-producing cells
80
Q

Functions of CD-4expressing T cells

A
  • Help initiate and mature immune responses
  • Activate macrophages to induce delayed-type hypersensitivity responses (DTH)
  • A subset of these cells suppress responses
81
Q

CD4 T cells can be further divided into

A
  • TH0, TH1, TH2, TH17 & Treg subgroups

- According to the spectrum of cytokines they secrete and the type of immune response that they promote

82
Q

TH1 cells

A
  • Promote local, antibody and cellular inflammatory, and DTH responses
83
Q

TH2 cells

A
  • Promote antibody production
84
Q

TH17 cells

A
  • Activate neutrophil responses
85
Q

Treg cells

A
  • Promote T-cell tolerance
86
Q

CD8 T cells also release cytokines, but are better known for

A
  • Ability to recognize & kill virally infected cells, foreign tissue transplants (non-self-grafts), and tumor cells as cytotoxic killer T cells
  • Also suppress immune responses
87
Q

T cells also produce memory cells that express

A
  • CD45RO
88
Q

Terminally differentiated effector CD4 and CD8 T cells express

A
  • Class II MHC antigen
89
Q

A variable number of T cells express the γδ TCR but do not express

A
  • CD4 or CD8
90
Q

T cell lymphocytes generally reside in

A
  • Skin & mucosa and are important for innate immunity
91
Q

NKT cells

A
  • T cells which share characteristics with NK cells
92
Q

Large, granular lymphocyte NK cells resemble

A
  • CD8 T cells in cytolytic function toward virally infected and tumor cells
  • Differ in mechanism for identifying target cells
93
Q

NK cells also have Fc receptors, which are used in

A
  • Antibody-dependent killing

- Also called antibody-dependent cellular cytotoxicity (ADCC or K) cells

94
Q

Cytoplasmic granules of T cells contain

A
  • Cytolytic proteins to mediate the killing
95
Q

Innate immunity

A
  • Mediates the initial protection against infections
  • Relies on mechanisms that exist before infection
  • Capable of rapid responses to microbes, and react in essentially the same way to repeat infections
96
Q

Adaptive immunity

A
  • Develops more slowly

- Mediated by lymphocytes and is stimulated by exposure to infectious agents

97
Q

Neutrophil nickname

A
  • Trash collector and disinfector

- Very effective at phagocytosis and killing bacteria

98
Q

Dendritic cell nickname

A
  • Billboard display

- Phagocytoses antigen & brings it to the lymph node to display to CD4 & CD8 T cells

99
Q

Macrophage nickname

A
  • Pac man
  • Phagocyte which is activated by interferon-γ & then becomes efficient at killing phagocytized microbes and producing cytokines
100
Q

Lymph node nickname

A
  • Police department
  • Repository for B and T cells
  • Evidence of infection is brought by the lymphatics or dendritic cells & other antigen presenting cells to the lymph node to activate the T cells to communicate with other cells through cytokines (like a radio) to be dispatched to take care of the problem
101
Q

CD4 T cell nickname

A
  • Desk sergeant/dispatch officer
  • Presented with the microbial problem by antigen presenting cells, it tells other cells to take care of the problems by producing cytokines
102
Q

CD8 T cell nickname

A
  • “Cop on the beat”/patrol officer
  • Activated in the lymph node & then moves to the periphery to patrol for virus infected or tumor cells
  • Then grabs the perpetrator and inactivates it
103
Q

B cell nickname

A
  • Product design and building company

- Pre-B cells and B cells alter the DNA of their immunoglobulin genes to produce the plans for a specific immunoglobulin

104
Q

Plasma cell nickname

A
  • Factory

- Immunoglobulin-producing factory with a small office (nucleus) and many assembly lines (ribosomes) for making antibody

105
Q

Mast cell nickname

A
  • Activatable chemical warfare unit

- Fc receptors for IgE that will trigger the release of histamines and other agents upon binding to an allergen signal

Medical Microbiology I (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions