Innate Immunity

Question 0

List the internal defenses

Answer 0

Antimicrobial substances, NK cells, phagocytes, inflammation, and fever

Question 1

What are external factors?

Answer 1

Skin and mucous membranes

Question 2

Epidermis

Answer 2

Provides a physical barrier to microbes

Question 3

Mucous membranes

Answer 3

Secretes mucus that moistens cavity surface

Question 4

Hairs

Answer 4

Trap and filter microbes, dust, and pollutants from air

Question 5

Cilia

Answer 5

Located in upper respiratory tract. Moves inhaled dust and microbes to the throat

Question 6

Lacrimal apparatus

Answer 6

Drains away tears in the eye

Question 7

Lysozyme

Answer 7

Contained in tears, saliva, perspiration, nasal secretions, and tissue fluids. Capable of breaking down cell walls of a bacteria

Question 8

Urine

Answer 8

Retards microbial colonization of the urinary system. Vaginal secretions are equivalent in females and are slightly acidic

Question 9

Defecation and vomiting

Answer 9

Expels microbes

Question 10

Sebum

Answer 10

Forms a protective film over the surface of the skin. pH from 3-5

Question 11

Perspiration

Answer 11

Flushes microbes from the skin

Question 12

Gastric juice

Answer 12

Contains HCl, enzymes, and mucus. pH of 1.2 - 3.0

Question 13

4 types of antimicrobial substances

Answer 13

IFNs
Complement system
Iron-binding proteins
Antimicrobial proteins

Question 14

IFNs

Answer 14

Three types. Released by virus-infected cells. Interferes with viral reproduction.

Question 15

Complement system

Answer 15

Caused cytolysis of microbes, promotes phagocytosis, and contributes to inflammation

Question 16

Iron-binding proteins

Answer 16

Reduces amount of iron to limit bacteria growth

Question 17

Types of iron-binding proteins

Answer 17

Transferrin (in blood and tissue fluids)
Lactoferrin (in milk, saliva, and mucus)
Ferritin (in liver, spleen, red bone marrow)
Hemoglobin (in red blood cells)

Question 18

Antimicrobial proteins (AMPs)

Answer 18

Short peptides that can attract dendritic cells and mast cells

Question 19

Types of AMPs

Answer 19

Dermicidin (from sweat glands)
Defensins & cathelicidins (from neutrophils, macrophages, and epithelia)
Thrombocidin (from platelets)

Question 20

NK cells

Answer 20

Present in spleen, lymph nodes, and red bone marrow. No membrane molecules. Able to kill infect cells and tumor cells. Attack any body cells that display abnormal plasma membrane proteins.

Question 21

Cytolysis

Answer 21

Perforin creates channels in membrane and extracellular fluid flows into it causing it to burst

Question 22

Fixed macrophages

Answer 22

Stand guard in specific tissues.

Question 23

Types of fixed macrophages

Answer 23

Histiocytes (connective tissue)
Stellate reticuloendothelial cells/Kupffer cells (liver)
Alveolar (lungs)
Microglia (CNS) 
Tissue macrophages (spleen, nodes)

Question 24

Stages of phagocytosis

Answer 24

``` Chemotaxis Adherence Ingestion Digestion Killing ```

Question 25

Chemotaxis

Answer 25

Chemically stimulated movement of phagocytes to damage sites

Question 26

Adherence

Answer 26

Attachment of phagocyte to microbe. Complement enhances adherence

Question 27

Ingestion

Answer 27

The pseudopods surround and engulf the microbe, forming a phagosome.

Question 28

Digestion

Answer 28

Enzymes in the phagolysosome breaks down cell walls and macromolecules

Question 29

Killing

Answer 29

Microbes get reduced to residual bodies.

Question 30

Inflammation

Answer 30

The nonspecific response of the body to tissue damage

Question 31

Characteristics of inflammation

Answer 31

Redness Pain Heat Swelling

Question 32

Stages of inflammation

Answer 32

Vasodilation and increase blood vessel permeability Emigration of phagocytes from blood to interstitial fluid Tissue repair

Question 33

Vasodilation

Answer 33

Permits defensive proteins and clotting factors to enter injured area. Helps remove microbial toxins and dead cells. Histamine, kinins, prostaglandins, leuktrienes, and complement all contribute.