(7) HOST RESISTANCE AND INFECTION Flashcards
Includes the first and second line of defense
Non-specific Host Resistance
- Includes immunology and the two major arms of the immune system
- Hypersensitivity and hypersensitivity reactions
Specific Host Resistance (Third Line of Defense)
Includes the skin and mucous membranes, cellular and chemical factors, and microbial antagonism
First Line of Defense
Includes transferrin, fever, interferons, complement system, acute-phase proteins, cytokines, inflammation, and phagocytosis
Second Line of Defense
Includes humoral immunity and cell-mediated immunity
Third Line of Defense
- General and serve to protect the body against many harmful substances
- Includes the innate or inborn resistance observed among species of animals and some persons who have a natural resistance to certain diseases
Non-specific Host Defense
- Physical/mechanical barriers
- Includes intact and unbroken skin
- Sticky mucus entrap invaders
First Line of Defense
Chemical factor on the skin that are part of the first line of defense
Sebum
Chemical factors found in saliva, tears, mucus, and colostrum that are part of the first line of defense
Secretory IgA, Lysozyme, and Lactoperoxidase
Low pH is a chemical factor that is part of the first line of defense
1. Skin - ______
2. Gastric Acid - _______
3. Vagina - ______
(1) pH 5.5
(2) pH 1-3
(3) pH 4.4
Chemical factors in epithelial cells that are part of the first line of defense
Beta Defensins
Chemical factor in gastric mucosal defenses that are part of the first line of defense
Pepsin
FIRST LINE OF DEFENSE
Factors accounting for skin’s ability to resist pathogens:
* (1) _____ of most areas of the skin
* (2) _________
* (3) _________
* (4) _________
* sloughing of (5) ______
(1) dryness
(2) acidity and temperature
(3) sebum
(4) perspiration
(5) dead skin cells
FIRST LINE OF DEFENSE
Factors accounting for mucous membranes’ ability to resist pathogens:
* (1) _____ production
* (2) _______
* (3) _______ - production superoxide radicals
* rapid (4) ______
* (5) _____ coverings
(1) lysozyme
(2) lactoferrin
(3) lactoperoxidase
(4) cell division
(5) mucociliary
FIRST LINE OF DEFENSE
Protection of the digestive system:
* (1) _______
* (2) ______ of the stomach
* (3) ______ of the intestines
* (4) _______
* (5) _______
(1) digestive enzymes
(2) acidity
(3) alkalinity
(4) bile
(5) peristalsis & defecation
FIRST LINE OF DEFENSE
Protection of the GUT:
* (1) ______
* expulsion of (2) ______
* acidity of the (3) ______
(1) urination
(2) mucus secretions
(3) vagina
FIRST LINE OF DEFENSE
_______ fight the invasion of new microorganisms in a particular anatomical site.
Resident microbes (First Line of Defense)
The inhibitory capability of the indigenous microflora has been attributed to the following factors:
* competition for colonization sites
* competition for nutrients
* production of substances that kill other bacteria - bacteriocins
Microbial Antagonism (First Line of Defense)
A factor of microbial antagonism that is the production of substances that kill other bacteria
Bacteriocins (First Line of Defense)
- A glycoprotein with a high affinity to iron
- FUNCTION: Store and deliver iron to host cells
Transferrin (Second Line of Defense)
- Body temperature greater than 37.8 ̊C
Fever (Second Line of Defense)
SECOND LINE OF DEFENSE
Fever augments the host’s defense by:
* stimulating (1) _____
* reducing available (2) _____
* inducing the production of (3) _____
(1) leukocytes
(2) free plasma iron
(3) IL-1
SECOND LINE OF DEFENSE
The following scenario illustrates one way in which fever develops during an infectious disease:
1. A patient has ______ caused by gram (-) bacteria.
- The bacteria releases ______ into the patient’s bloodstream.
- ______ ingest the endotoxin.
- The ingested endotoxin stimulates the phagocytes to produce ______.
- IL-1 stimulates the hypothalamus to produce ______.
- Once metabolized, the prostaglandins cause the hypothalamic thermostat to be set at a ______.
- The increased thermostatic reading sends out signals to the nerves surrounding the peripheral blood vessels, causing _______.
- The increased body heat continues until the temperature of the blood supplying the hypothalamus matches the _______.
(1) septicemia
(2) endotoxin
(3) Phagocytes
(4) IL-1
(5) prostaglandins
(6) higher level
(7) vasoconstriction
(8) elevated thermostat reading
SECOND LINE OF DEFENSE
Detrimental effects of fever:
* increased (1) _____
* increased (2) _____
* increased (3) _____
* mild to severe (4) _____
(1) HR
(2) metabolic rate
(3) caloric demand
(4) dehydration
- Small, antiviral proteins produced by virus-infected cells
- Not virus-specific; but species-specific
Interferons (Second Line of Defense)
SECOND LINE OF DEFENSE
* Three types of interferons:
1. ____ (B-cells, monocytes, macrophages)
2. ____ (fibroblasts, other virus-infected cells)
3. ____ (T-cells and NK cells)
(1) Alpha
(2) Beta
(3) Gamma
A group of approximately 30 different proteins found in normal blood plasma
Complement (Second Line of Defense)
The proteins interact with each other in a stepwise manner known as the “complement cascade.”
Complement System (Second Line of Defense)
SECOND LINE OF DEFENSE
*The major consequences of complement activation are the following:
1. Initiation and amplification of ______
2. Attraction of ______ to sites where they are needed
3. Activation of ______
4. _____ of bacteria and other foreign cells
5. Increased ______ by phagocytic cells
(1) inflammation
(2) phagocytes
(3) leukocytes
(4) Lysis
(5) phagocytosis
- Enhances resistance to infection and promoting repair of damaged tissue
- Includes the following:
C-Reactive Proteins, Serum Amyloid A Proteins, Protease Inhibitors, Coagulation Proteins
Acute-Phase Proteins (Second Line of Defense)
- Chemical mediators
- Enable cells to communicate w/ each other
- Chemical messengers
Cytokines (Second Line of Defense)
SECOND LINE OF DEFENSE
* Some cytokines are _______, recruiting phagocytes to location, and direct role in host defense
chemoattractants
- Normal response to any local injury, irritation, microbial invasion, or bacterial toxin
Inflammation (Second Line of Defense)
SECOND LINE OF DEFENSE
* The three major events in acute inflammation:
1. An increase in the _______, which increases blood flow to the site.
- Increased _______, allowing the escape of plasma and plasma proteins.
- Egress (exit) of _______ from the capillaries and their accumulation at the site of injury.
(1) diameter of capillaries (vasodilation)
(2) permeability of the capillaries
(3) leukocytes
SECOND LINE OF DEFENSE
* Primary purposes of the inflammatory response:
1. Localize an ______
2. Prevent the spread of ______
3. Neutralize any _____ being produced at the site
4. Aid in the repair of ______
(1) infection
(2) microbial invaders
(3) toxins
(4) damaged tissue