Microbiology Exam 3. Ch 16 Study Guide

Front 1

Innate Immunity

Back 1

1) The immunity that is present at birth. They are always present and available to provide a rapid response.
2) Innate immunity does not involve specific recognition of a microbe
3) It is the first (Skin and Mucous) and second (Natural killer cells, etc) line of defense
4) The early warning system to stop microbes from entering and kill those that do

Front 2

Adaptive Immunity

Back 2

1) Adaptive immunity is based on a specific response to a specific microbe once a microbe has breached the innate immunity defenses.
2) Slower to respond
3) Has a memory component
4) Involves lymphocytes, T and B cells

Front 3

Innate Immunity: First Line of Defense

Back 3

1) Intact skin
2)Mucous membranes and their secretions
3)Normal Microbiota

Front 4

Innate immunity: Second line of Defense

Back 4

1) Phagocytes, such as neutrophils, eosinophils, dendritic cells, and macrophages.
2) Inflammation
3) Fever
4) Antimicrobial substances

Front 5

Adaptive immunity: Third line of Defense

Back 5

1) Specialized Lymphocytes: T cells and B cells
2) Antibodies

Front 6

First Line of Defense: The Dermis

Back 6

The skin's thicker, inner portion is composed of connective tissue.

Front 7

Toll-Like Receptors (TLRs)

Back 7

Protein receptors that activate the response of the Innate immune system. TLRs attach to Pathogen associated Molecular patterns and induce defense cells to release cytokines

Front 8

First Line of Defense: The Epidermis

Back 8

The outer thinner portion of skin that is in direct contact with the external environment. The top layer of epidermal cells is dead and contains a protective protein called Keratin.
Periodic shedding helps remove microbes from the surface.
Dryness of the skin helps inhibit microbial growth
Closely packed cells and continuous layering keep microbes from penetrating skin

Microbes may enter if this layer is broken from burns, cuts, stab wounds etc.

Front 9

First Line of Defense: Mucous Membrane

Back 9

Consists of an epithelial layer and an underlying connective tissue layer. They line the entire gastrointestinal, genitourinary, and respiratory tracts
Secretes a fluid called Mucus, a slightly viscous glycoprotein produced by goblet cells.

Front 10

Mucus

Back 10

a slightly viscous glycoprotein produced by goblet cells.
Traps microorganisms that enter
The nose has Mucus coated hairs
Keeps the tracts from dessication though certain bacteria can thrive in Mucus and penetrate the membrane

Front 11

Lacrimal Apparatus

Back 11

A group of structures that manufacture and drains away tears to protect the eyes
Maintains a continual washing action

Front 12

Saliva

Back 12

Saliva is produced by the salivary glands and helps dilute the numbers of microorganisms and wash them from both the surface of the teeth and the mucus membrane of the mouth.
* Saliva contains an enzyme and other substances that inhibit growth such as Lysozymes, urea, and uric acid

Front 13

Cilia and the Ciliary Elevator

Back 13

The lower respiratory tract is covered in tiny hairs called Cilia.
The Cilia move synchronously to propel trapped dust and microbes upward toward the throat (the elevator)

Front 14

Epiglottis

Back 14

Small lid of cartilage that covers the Larynx (voice box) during swallowing

Front 15

First line of defense: Urine and Vaginal secretions

Back 15

Both help to prevent microbial colonization by moving microorganisms out of the body

Front 16

First Line of Defense: Peristalsis, defecation and vomiting

Back 16

Peristalsis is a series of coordinated contractions that propel food along the gastrointestinal tract
This results in defecation or vomiting

Front 17

First Line of Defense
Chemical Factors: Sebum

Back 17

An oily substance produced by the Sebaceous (oil) glands.
Sebum forms a protective film over the surface of skin
Sebum is partially made of fatty and lactic acids that cause low PH (between 3 and 5) and inhibits bacterial growth

Front 18

First Line of Defense
Chemical Factors: Perspiration

Back 18

Produced by the sweat glands, perspiration helps maintain body temperature, eliminate certain wastes and flush microorganisms from the surface of the skin
**** Sweat contains Lysozyme, an enzyme capable of breaking down cell walls of gram Positive bacteria (some Gram negative)

Front 19

Acne

Back 19

Bacteria that can metabolize sebum create free fatty acid, that cause an inflammatory response associated with acne

Front 20

Body Odor

Back 20

Bacteria live commensally on the skin and decompose sloughed off skin cells. The resultant organic molecules and end-products or their metabolism, Produce Body Odor

Front 21

First Line of Defense:
Chemical Factors: Gastric Juices

Back 21

Produced by glands in the stomach. Very acidic and sufficient to destroy bacteria and most bacterial toxins

Front 22

Vaginal Secretions

Back 22

Chemical: Low PH inhibits microbial growth

Physical: Secretion moves bacteria from body

Front 23

Urine

Back 23

Chemical: Includes lysozymes an acidic PH and lacic acid

Physical: Removes microbes from body, inhibits colonization

Front 24

Gastric Juices: C. botulinum and S.aureus

Back 24

These bacteria are not destroyed by gastric juices

Front 25

Gastric Juices: Heliobacter pylori

Back 25

Can neutralize gastric juices that allows it to grow in stomach.

Initiates an Immune response that results in Gastritis and Ulcers

Front 26

Normal Flora and Innate Immunity: Candida albicans

Back 26

Normal flora in the vagina alters PH and inhibits the growth of Candida albicans

Front 27

Normal Flora and Innate Immunity: E. Coli

Back 27

In the large intestines, E. coli produce bacteriocins that inhibits growth of salmonella and shingella

Front 28

Leukocytes

Back 28

Are white blood cells that fall into two catagories, Granulocytes and agranulocytes.

Front 29

Granulocytes

Back 29

Have large granules that can be seen with a microscope. There are three types
1) Neutrophils
2) Basophils
3) Eosinophils

Front 30

Neutrophils

Back 30

1) Most numerous.
2) They are highly phagocytic and motile.
3) Active in the initial stages of infection
4) Can leave the blood, enter infected tissues, and destroy foreign microbes

Front 31

Basophils

Back 31

Produce Histamine important in inflammation and allergic responses

Front 32

Eosinophils

Back 32

Somewhat phagocytic and have the ability to leave blood.
Major function is to produce toxic proteins against certain parasites

Front 33

Agranulocytes

Back 33

Have granules but they can't be seen under a microscope. Three types:
1) Monocytes
2) Dendritic Cells
3) Lymphocytes

Front 34

Monocytes

Back 34

Monocytes are not actively phagocytic until they leave circulating blood and mature into macrophages.
Macrophages remove microorganisms through phagocytosis
Macrophages also dispose of worn out blood cells

Front 35

Dendritic Cells

Back 35

Derived from monocytes, they are especially abundant in the epidermis of the skin.
Dendritic cells destroy microbes through Phagocytosis and initiate immune response

Front 36

Lymphocytes

Back 36

include 3 types
1) Natural Killer Cells
2) T Cells
3) B Cells

Front 37

Natural Killer Cells (NK)

Back 37

Found in the blood and in the spleen, lymph nodes and red bone marrow.
NK destroy target cells by cytolysis and apoptosis

Front 38

How do Natural Killer Cells work?

Back 38

1) NK cells attack any cell that displays abnormal or unusual surface proteins.
2) The binding to a target cell causes the release of vesicles containing toxin substances such as Perforin, which inserts into the plasma membrane.
3) As a result, extracellular fluid flows into the target cell and the cell bursts (cytolosis)
4) NK cells also release Granzymes, which are protein digesting enzymes that induce the cell to undergo apoptosis (self destruction). This kills the cell but not the microbe. The microbe is released that can be consumed through phagocytosis

Front 39

Leukocytosis

Back 39

An increase in white blood cells are a protective response to fight microbes

Front 40

Leukopenia

Back 40

Impaired white cell production of the effect of increased sensitivity of white blood cell membranes to complement

Front 41

Differential White Blood Cell Count

Back 41

The calculation of the percentage of each type of white cell

Front 42

Lymphatic nodes

Back 42

Lymph nodes are the sites of activation of T cells and B cells, which destroy microbes by immune response.

Front 43

The Lymphatic system: The Spleen

Back 43

Contains lymphocytes and macrophages that monitor the blood for microbes and secreted products.

Front 44

The Lymphatic system: The thymus

Back 44

The site of T cell maturation. It also contains dendritic cells and macrophages

Front 45

The Lymphatic system: The Tonsils and Peyer's Patch

Back 45

Both are large aggregations of Lymphatic tissue designed to protect against microbes that are ingested or inhaled

Front 46

Phagocyte

Back 46

Cells that perform phagocytosis

Front 47

Phagocytosis

Back 47

The means by which the body counter acts infection when certain cells consume microbes and destroy them

Front 48

What are the mechanisms of Phagocytosis? (7 Mechanisms)

Back 48

1) Chemotaxis and adheranceof microbe to phagocyte
2) Ingestion of microbe by phagocyte
3) Formation of phagosome
4) Fusion of the phagosome with a lysosome to form a phagolysosome
5) Digestion of ingested microbe by enzymes
6) Formation of residual body containing indigestible material
7) Discharge of wast materials

Front 49

Fixed macrophages

Back 49

Resident in certain tissues and organs of the body. (liver, lungs, nervous system, spleen, etc)

Front 50

The Mechanism of Phagocytosis: Chemotaxis

Back 50

The chemical attraction of phagocytes to microorganisms

Front 51

The Mechanism of Phagocytosis: Adherence

Back 51

The attachment of the phagocyte's plasma membrane to the surface of the microorganism or other foreign material

Front 52

The Mechanism of Phagocytosis: Opsonization

Back 52

The coating of a microorganism with serum proteins so that it can be more easily phagocytized. These proteins promote attachment of the microorganisms to the phagocyte

Front 53

The Mechanism of Phagocytosis: Ingestion

Back 53

The plasma membrane of the phagocyte extends projections called pseudopods that engulf the organism

Front 54

The Mechanism of Phagocytosis: Phagosome

Back 54

After the organism is engulfed, the sac is called a phagosome

Front 55

The Mechanism of Phagocytosis: Digestion

Back 55

Within the cytoplasm, it comes into contact with lysosomes that contain digestive enzymes and bactericidal substances

Front 56

The Mechanism of Phagocytosis: Phagolysosome

Back 56

On contact with a lysosome, the phagosome and lysosome fuse to become a phagolysosome where the contents are digested

Front 57

The Mechanism of Phagocytosis: Residual Body

Back 57

the indigestible portion

Front 58

The Mechanism of Phagocytosis: Discharge

Back 58

The residual body is discharged as waste

Front 59

List the stages of inflamation

Back 59

After tissue damage

*A) Tissue Damage

1) Chemicals such as histamine, kinins, prostaglandins etc. are released by damaged cells
2) Blood clot forms
3) Abscess starts to form

*B) Vasodilation and increased permeability of blood vessels

4) Marginization- phagocytes stick to the endotheium

*C) Phagocyte Migration and phagocytosis

5) Diapedesis - Phagocytes squeeze between endothelial cells
6) Phagocytosis of invading bacteria

*D) Tissue repair

Front 60

The four signs and symptoms of inflammation

Back 60

1) Redness
2) Pain
3) Heat
4) Swelling

Front 61

Inflammation: Vasodilation

Back 61

Increases blood flow to the damaged area and is responsible for redness and associated heat

Front 62

Inflammation: Increased permeability

Back 62

Permits defensive substances normally retained within the blood to pass through the walls and into the injured area. This is responsible for the edema (increase in fluid)

Front 63

Inflammation: Kinins

Back 63

Help cause vasodilation and increased permeability. Play a role in chemotaxis by attracting granulocytes, chiefly neutrophils

Front 64

Inflammation: Prostoglandins

Back 64

Intensify the effect of histamine and kinins and help phagocytes move through capillary walls.

Front 65

Inflammation: Leukotrienes

Back 65

Produced by mast cells and basophils. Cause increased permeability of blood vessels and help attach phagocytes to pathogens

Front 66

The Cause and effects of Fever

Back 66

Is an abnormally high body temperature.

Cause: The destruction of gram negative bacteria by phagocytosis, the cytokine interleukin 1 is released along with others. IL1 causes the hypothalamus to release prostoglandins that reset the hypothalamic pressure

Effects: The raised temperature causes the body to shiver, raise metabolism, and constrict blood vessels

IL1 also helps to step up T cell production

Front 67

The Complement System: Outcomes of complement activation Fig. 16.9

Back 67

1) Inactivated C3 splits into activated C3a and C3b
2) C3b binds to microbe, resulting in Opsonization
3) C3b splits C5 into C5a and C5b
4) C5b, C6, C7, and C8 bind together sequentially and insert into the microbial plasma membrane. C5b through C8 act as a receptor to attract a C9 fragment, and additional C9 fragments are added to form a channel. Together, C5b through C8 and the multiple C9 fragments form the membrane attack complex, resulting in cytolosis
5) C3a and C5a cause mast cells to release histamine, resulting in inflammation; C5a attracts phagocytes

Front 68

The Complement System: The Classical pathway (16.12)

Back 68

Classic pathway includes antibodies.
1) C1 is activated by binding antigen-antibody complexes
2) Activated C1 splits C2 into C2a and C2b, and C4 into C4a and C4b
3) C2a and C4b combine and activate C3....
3)

Front 69

The Complement System: The Alternative pathway (16.13)

Back 69

No antibodies involved.

1) C3 combines with factors B, D, P on the surface of a microbe
2) This cause C3 to split into fragments C3a and C3b ...

Front 70

The Complement System: The Lectin pathway

Back 70

Cytokines stimulate the liver to release Lectin Proteins
1) Lectin binds to invading cell
2) Bound Lectin splits C2 and C4
3) C2a and C4b combine and activate C3

Front 71

Interferons (IFNs)

Back 71

The infected host counters viral infections with a family of cytokines that interfere with viral replication

Front 72

Interferons (IFNs): Antiviral action of IFNs (16.15)

Back 72

1) Viral RNA from an infecting virus enters the cell
2) The virus replicates
3) The host cell produces Interferon
4) The IFNs bind to the plasma membrane of an uninfected neighboring cell
5) The neighboring cell is induced to produce antiviral proteins (AVPs)
6) Released virus infects neighboring cells
7) AVPs degrade viral mRNA