Microbiology Chapter 16

Front 1

Resistance

Back 1

ability of host to ward off disease.

Front 2

Susceptibility

Back 2

lack of resistance to a pathogen

Front 3

Non-specific reisistance

Back 3

host mechanishms that protect the body against all pathogens regardless or species

Front 4

Nonspecific

Back 4

First Line Defense
Second Line of Defense

Front 5

Specific

Back 5

Third Line of Defense

Front 6

1st line of defense (non specific)

Back 6

skin, mucous membrane & their secretions, normal microbiota

Front 7

Barriers

Back 7

Skin-dermis, epidermis and immunologic cells

Front 8

Dermis

Back 8

inner thicker layer of connective tissue

Front 9

Epidermis

Back 9

outer thinner layer of epithelial cells with top layers of dead cells containing keratin (water proofing protein)

Front 10

Immunologic cells

Back 10

monitor for pathogens

Front 11

Mucous membranes

Back 11

Line the respiratory, gastrointestinal and genitourinary tracts
Epithelial layer which secretes mucus plus ciliary escalator
Not as resisitant as skin
some pathogesn can grow in mucus

Front 12

Other Defenses

Back 12

Lacrimal apparatus (tears)
Saliva
Urine Flow
Coughing
Sneezing

Front 13

Chemical Defenses

Back 13

Sebum
Sweat
Grastric juice

Front 14

Sebum

Back 14

Fatty acids produced by oil glands in skin
pH 3 - 5 inhibits microbial growth

Front 15

Sweat

Back 15

contains lysozyme (also present in tears, saliva, nasal fluids, tissue fluids.)

Front 16

Gastric Juice

Back 16

HCl (pH 1.2 - 3). mucus. digestive enzymes

Front 17

2nd Line of Defense

Back 17

Phagocytosis
Inflammation
Antimicrobial substances

Front 18

Phagocytosis

Back 18

ingestion & digestion of microorganisms by certain white blood cells

Front 19

Phagocytosis

Back 19

1. Chemotaxis and adherence of microbe to phagocyte.
2. Ingestion of microbe by phagocyte
3. Formation of a phagosome
4. Fusion of the phagoseome with a lysosome to form a phagolysome
5. Digestion of ingested microbe by enzymes
6. Formation of residual body containing indigestible material
7. Discharge of waste material

Front 20

Inflammation

Back 20

body's response to tissue damage due to infection, electrical charges, sharp objects, and chemical agents; resulting in redness, pain, heat and swelling

Front 21

Leukocytes

Back 21

White Blood Cells

Front 22

Leukocytosis

Back 22

increase in number of white blood cells in response to certain infections
(appendicits, pneumonia, mononucleosis)

Front 23

Leukopenia

Back 23

Decrease in number of white blood cells in response to other infections. (salmonellosis, brucellosis, viral infection)

Front 24

Differentail White Blood Cell Count

Back 24

diagnostic test to determine changes in WBC count

Front 25

Lymphatic System

Back 25

Phagocytes can migrate to areas of tissue damage or can be fixed in lymph nodes

Front 26

Opsonins

Back 26

protiens that coat microorganisms & stimulate phagocytosis

Front 27

Inflammation

Back 27

The inflammatory response is an attempt by the body to restore and maintain homeostasis after injury and is an integral part of body defense

Destroys harmful agents by confining & walling off foreign objects; repairs & replaces damaged tissue.

Vasodilation & increased blood vessel permeability.

Phagocyte migration. (get WBCs there)

Tissue repair. (Stimulate mitosis to repair tissue)

Front 28

Diapedesis

Back 28

Adhesion molecules are activated on the surface of the endothelial cells on the inner wall of the capillaries allowing the leukocytes to squeeze through the space between the endothelial cells.

Front 29

Phagocyte Migration

Back 29

Smooth muscles around larger blood vessels contract to slow the flow of blood through the capillary beds at the infected or injured site. This gives more opportunity for leukocytes to adhere to the walls of the capillary and squeeze out into the surrounding tissue

Front 30

Activation of Coagulation Pathway

Back 30

causes fibrin clots to physically trap the infectious microbes and prevent their entry into the bloodstream.

Front 31

Vasodilation & Increase Blood Vessel Permeability

Back 31

The endothelial cells that make up the wall of the smaller blood vessels contract. This increases the space between the endothelial cells resulting in increased capillary permeability

Front 32

Complement

Back 32

Group of 20 proteins in blood.

Complements immune reactions involving antibody (Ab).

Involved in lysis of foreign cells, inflammation, phagocytosis (opsonization).

Binds to Ab-Ag complexes.

Front 33

Complement

Back 33

C3 complement mediates/starts series of events - inflammation, opsonization and cytololysys

2 pathways- classical and alternative

Front 34

Interferons (IFNs)

Back 34

Infecting virus induces the host cell to produce interferon on RNA which is translated into alpha and beta interferon

Interferon released by host cell bind to other non infected near by host cells synthesizing antiviral proteins (AVPs)

inhibits protein synthesis and interfere with viral replication

Front 35

Interferons

Back 35

1. Viral RNA from an infecting virus enters the cell
2. The infecting virus replicates into new viruses
3. The infecting virus also induces the host cell to produce interferon on the RNA (IFN-mNA), which is translated into alpha and beta interferons.
4. Interferons released by the virus-infected host cell bind to plasma membrane or nuclear membrane receptors on uninfected neighboring host cells inducing them to synthesize antiviral proteins (AVPs). These include oligoadenylate synthetase and protein kinase
5. New viruses released by the virus-infected host cell infect neighboring host cells.
6. AVPs degrade viral m-RNA and inhibit protein synthesis and thus interfere with viral replication.

Front 36

Phagocytosis

Back 36

1. Chemotaxis and adherence of 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 waste material

Front 37

Inflammation

Back 37

walling of localized area via swelling
isolation - infection can't spread
blood vessel perm ability allows for movement of WBCs from lymphatic system to vascular system to get where they need to be. Diapedesis- WBCs squeeze through. Clot to wall off and not let infection into bloodstream.
Stimulate mitosis for tissue repair.

Front 38

Neutrophils

Back 38

Function: phagocytosis
grandulocytes
60 - 70% of leukocytes
4 um

Front 39

Macrophage

Back 39

A phagocyte cell
A mature monocyte

monocyte are not actively phagocytic until they leave circulating blood, enter body tissue and mature into macrophage

Front 40

Complement Cell Lysis

(Cytoloysis)

Back 40

C3b initiates a series of reactions involving C5 - C9 collectively called the membrane attack complex. This complex forms circular transmembrane channels (lesions) in the antigenic cell's membrane, witch C9 proteins possibly playing a key role

The results is leakage of the cell's contents - cytolysis through transmembrane channel.