CHAPTER 12: MICROBIOLOGY FUNDAMENTALS A
CLINICAL APPROACH, 4TH EDITION COMPLETE NEWEST
VERIFIED VERSION
1.Host defense mechanisms - answer Multilevel network of innate, nonspecific
protections and specific immunities
2.First line of defense - answer Protective barrier (skin & mucous membranes)
> Any barrier that blocks invasion at the portal of entry
> Limits access to the internal tissues of the body
> Not considered a true immune response because it does not involve
recognition of foreign substances, is very general in action
3.Three types of barriers: answer physical, chemical, genetic
4.Second line of defense - answer Eater cells (NK cells & macrophages) - innate
immunity
> Internalized system of protective cells & fluids
> Includes inflammation and phagocytosis
> Acts rapidly at both the local and systemic levels once the first line of defense
has been circumvented
> Generalized and nonspecific defenses that support and interact with specific
immune responses: phagocytosis, inflammation, antimicrobial proteins, fever
,5.Third line of defense - answer Smart cells (antibodies, B-cells, & T-cells) -
learned immunity
> Acquired on an individual basis as each foreign substance is encountered by
lymphocytes
> The reaction with each different microbe produces unique protective
substances
> Provides long-term immunity
6.Skin - answer Stratum corneum: tough outer layer that is impervious and
waterproof
> Constant sloughing of the outer layers of skin removes microbes
> Hair shaft is periodically shed and follicle cells are desquamated
> Flushing effect of swear removes microbes
7.Mucous membranes - answer Digestive, urinary, and respiratory tracts, and of
the eye
> Mucous coat impedes entry and attachment of bacteria
> Blinking and tear production flush the eye's surface
> Constant flow of saliva carries microbes to the stomach
> Vomiting and defecation evacuate noxious substances from the body
,8.Respiratory tract - answer Nasal hair traps larger particles
> Copious flow of mucus and fluids provides flushing action
> Ciliated epithelium conveys particles trapped in mucus toward the pharynx
> Sneeze reflex expels a large amount of air at high velocity
> Foreign matter in the bronchi, trachea, and larynx triggers coughing to eject
irritants
9.Genitourinary tract - answer Protection through the continuous trickle of urine
though ureters
> Periodic bladder emptying flushes urethra
> Vaginal secretions provide cleansing of the lower reproductive tract in females
10.Resident microbiota - answer Trains host defenses so that commensals are
kept in check and pathogens are eliminated
> Interruptions in this process may lead to immunologic disturbances in the gut
> Increased antibiotic use and efforts to free our environment from microbes may
contribute to IBD
> "Ill-trained" gut defense inappropriately responds to commensals
11.Nonspecific chemical defenses - answer Sebaceous secretions exert an
antimicrobial effect
> Specialized glands of the eyelids lubricate the conjunctiva with an antimicrobial
secretion
, > Digestive juices and bile in the intestine are destructive to microbes
> Semen contains an antimicrobial chemical
> Vagina has a protective acidic pH maintained by normal flora
12.Lysozyme - answer An enzyme found in tears and saliva that hydrolyzes the
peptidoglycan in the cell wall of bacteria
> High lactic acid & electrolyte content of sweat
> Acidic pH and fatty acid content of the skin
13.Genetic differences in susceptibility - answer Differences in susceptibility can
arise in mutations in the genes that code for components of the immune system
> Loss of immunity or absence of normal immunity demonstrate the vital need
for barriers of all types
> Patients with severe burns are very susceptible to all kinds of infections
> Blockages in salivary glands, tear ducts, intestine, and urinary tract are at
greater risk
> The first line of defense alone is not sufficient protection - inflammation,
phagocytosis, and specific immune responses are necessary
Immunology - answer The study of all features of the body's second and third lines
of defense
Study of the body's response to infectious agents
CLINICAL APPROACH, 4TH EDITION COMPLETE NEWEST
VERIFIED VERSION
1.Host defense mechanisms - answer Multilevel network of innate, nonspecific
protections and specific immunities
2.First line of defense - answer Protective barrier (skin & mucous membranes)
> Any barrier that blocks invasion at the portal of entry
> Limits access to the internal tissues of the body
> Not considered a true immune response because it does not involve
recognition of foreign substances, is very general in action
3.Three types of barriers: answer physical, chemical, genetic
4.Second line of defense - answer Eater cells (NK cells & macrophages) - innate
immunity
> Internalized system of protective cells & fluids
> Includes inflammation and phagocytosis
> Acts rapidly at both the local and systemic levels once the first line of defense
has been circumvented
> Generalized and nonspecific defenses that support and interact with specific
immune responses: phagocytosis, inflammation, antimicrobial proteins, fever
,5.Third line of defense - answer Smart cells (antibodies, B-cells, & T-cells) -
learned immunity
> Acquired on an individual basis as each foreign substance is encountered by
lymphocytes
> The reaction with each different microbe produces unique protective
substances
> Provides long-term immunity
6.Skin - answer Stratum corneum: tough outer layer that is impervious and
waterproof
> Constant sloughing of the outer layers of skin removes microbes
> Hair shaft is periodically shed and follicle cells are desquamated
> Flushing effect of swear removes microbes
7.Mucous membranes - answer Digestive, urinary, and respiratory tracts, and of
the eye
> Mucous coat impedes entry and attachment of bacteria
> Blinking and tear production flush the eye's surface
> Constant flow of saliva carries microbes to the stomach
> Vomiting and defecation evacuate noxious substances from the body
,8.Respiratory tract - answer Nasal hair traps larger particles
> Copious flow of mucus and fluids provides flushing action
> Ciliated epithelium conveys particles trapped in mucus toward the pharynx
> Sneeze reflex expels a large amount of air at high velocity
> Foreign matter in the bronchi, trachea, and larynx triggers coughing to eject
irritants
9.Genitourinary tract - answer Protection through the continuous trickle of urine
though ureters
> Periodic bladder emptying flushes urethra
> Vaginal secretions provide cleansing of the lower reproductive tract in females
10.Resident microbiota - answer Trains host defenses so that commensals are
kept in check and pathogens are eliminated
> Interruptions in this process may lead to immunologic disturbances in the gut
> Increased antibiotic use and efforts to free our environment from microbes may
contribute to IBD
> "Ill-trained" gut defense inappropriately responds to commensals
11.Nonspecific chemical defenses - answer Sebaceous secretions exert an
antimicrobial effect
> Specialized glands of the eyelids lubricate the conjunctiva with an antimicrobial
secretion
, > Digestive juices and bile in the intestine are destructive to microbes
> Semen contains an antimicrobial chemical
> Vagina has a protective acidic pH maintained by normal flora
12.Lysozyme - answer An enzyme found in tears and saliva that hydrolyzes the
peptidoglycan in the cell wall of bacteria
> High lactic acid & electrolyte content of sweat
> Acidic pH and fatty acid content of the skin
13.Genetic differences in susceptibility - answer Differences in susceptibility can
arise in mutations in the genes that code for components of the immune system
> Loss of immunity or absence of normal immunity demonstrate the vital need
for barriers of all types
> Patients with severe burns are very susceptible to all kinds of infections
> Blockages in salivary glands, tear ducts, intestine, and urinary tract are at
greater risk
> The first line of defense alone is not sufficient protection - inflammation,
phagocytosis, and specific immune responses are necessary
Immunology - answer The study of all features of the body's second and third lines
of defense
Study of the body's response to infectious agents
