Chapter 14 Nonspecific Host Defenses

Front 1

Lysozyme

Back 1

Degrades cell wall of bacteria, in tears, saliva

Front 2

Nonspecific chemical defenses:

Back 2

Skin oils, lysozyme, HCl, digestive juices, bile, semen has antimicrobial chemical, vagina has acidic pH

Front 3

Immunology definition

Back 3

The study of the body’s second and third lines of defense

Front 4

RES fxns (3)

Back 4

Surveillance of the body, recognition of foreign material, destruction of foreign invaders

Front 5

What is RES and what does it include (3)

Back 5

Reticuloendothelial system, extracellular fluid, bloodstream, lymphatic system

Front 6

RES system

Back 6

Reticuloendothelial system: network of connective tissue fibers that interconnects cells and meshes with the connective tissue network surrounding organs. Inhabited by phagocytes, mononuclear phagocyte system

Front 7

Lymphatic sys fxns

Back 7

Provides a way to return ECF to the circulatory system, transports WBCs, fats, infectious agents, filters foreign material and presents it to immune cells

Front 8

Primary lymphoid organs

Back 8

Are the sites of lymphocyte maturation, thymus and bone marrow

Front 9

Secondary lymphoid organs

Back 9

Spleen and lymph nodes. BALT, GALT (gut-associated lymphoid tissue), MALT (Mucosal associated lymphoid tissue)

Front 10

Thymus

Back 10

Huge as fetus and shrinks with age, disappears in adulthood. Site of T cell maturation

Front 11

Lymph nodes: what are they and fxn

Back 11

Small nodules located along lymph nodes their fxn is to filter out pathogens, foreign material

Front 12

Spleen

Back 12

Structurally similar to lymph node, filters blood to remove worn out RBCs and pathogens

Front 13

Actions of the second line of defense: (6)cu

Back 13

Recognition

Inflammation

Phagocytosis

Cytokines

Fever

Complement

Hint 13

RIPCFC

Front 14

How recognition works

Back 14

Macrophages have receptor proteins. Toll-like receptors, detect LPs, peptidoglycans, flagellum, bacterial nucleotide sequences. Pathogens bind to these and in response, macrophage releases chemicals which stimulate inflammation (nonspecific) b & T cells (specific)

Front 15

Cytokines

Back 15

Chemical signals released by cells. Bind to surface receptors and regulate cell fxn.

any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system and have an effect on other cells.

Front 16

Cytokine classes and what the do (4)

Back 16

Chemokines- involved in chemotaxis

Interferons- antiviral, kill cancer cells (sometimes)

Interleukins- produced by leukocytes

Tumor necrosis factor- kills tumor cells, initiates inflammation

Front 17

Inflammatory process (4)

Back 17

Release of chemotactic factors

Dilation of blood vessels

Leakage of fluid from vessels

migration of phagocytes (neutrophils, macrophages) and lyphocytes

Front 18

Fever definition

Back 18

Response to infection, especially bacterial. Internal thermostat maintained by hypothalamus.

Front 19

Fever inducing agents (exo and endo)

Back 19

exogenous pyrogens- products of infectious agents. external

endogenous pyrogens- chemicals secreted by WBCs, IL-1, TNF

Front 20

Benefits of (mild) fever

Back 20

-inhibits multiplication of temp-sensitive microbes, like some cold virus, fungi, TB

-impedes growth of bacteria by reducing available iron

-lactoferrin

-increases metabolism & stimulates immune reactions

Front 21

3 main types of phagocytes

Back 21

Neutrophils, eosinophils, macrophages

Front 22

Neutrophils

Back 22

Most common in body, arrive early at site of infection, react to other foreign materials & to damaged tissue. After death, form NETs (neutrophil extracellular traps) becomes sticky to immobilize pathogens

Front 23

Eosinophils

Back 23

attracted to sites of parasitic infections and antigen-antibody reactions (allergy)

Front 24

macrophages

Back 24

derived from monocytes; engulf and kill foreign cells

Front 25

Fxns of phagocytes (3 main)

Back 25

1. survey tissues and discover microbes, particulate matter, & dead/injured cells

2. ingest and eliminate these materials

3. extract immunogenic info from foreign matter

Front 26

The sequential events in phagocytosis (7)

Back 26

1. phagocyte attracted to bacteria by chemotaxis

2. adhesion to bacteria

3. engulfment into phagocytic vacuole

4. phagosome digestive vacole

5. lysozome fuses w phagosome, forming phagolysozome

6. kill & destroy bacteria

7. release residual debris

Front 27

complement system

Back 27

consists of 9 blood proteins that work in concert to destroy bacteria & viruses. C1-C9 names in order of discovery, not action

Front 28

3 pathways complement system is actived

Back 28

classical, MB-Lectin, Alternative

Front 29

classical pathway

Back 29

complement-fixing antibodies have rapid, specific effects

Front 30

MB-lectin pathway

Back 30

Mannose-binding lectin (MBL) binds mannose on pathogen surfaces. Nonspecific for bacteria and viruses

Front 31

Alternative pathway

Back 31

Molecules on surface of bacteria, viruses, and parasites. Nonspecific

Front 32

activation of complement leads to 3 protective outcomes:

Back 32

inflammation, lysis of foreign cells, opsonization

Front 33

(complement outcome)inflammation:

Back 33

C3a and C5a induce changes that contribute to local vascular permeability & attract phagocytes

Front 34

(complement outcome) lysis of foreign cells:

Back 34

formation of membrane attack complexes creates pores in cell membranes, disrupting integrity of the cell (gram - cells, parasites, viruses)

Front 35

(complement outcome) opsonization

Back 35

C3b binds to foreign microorganisms or cells making them more susceptible to phagocytosis, functioning as an opsonin