Microbiology Test 2

• Younger children 1-4
• Older adults over 50

Correct chemical receptors are not present on human cells for pathogens that affect other species. Also the conditions may be incompatible with those needed for pathogen's survival

• bacteria
• viruses
• fungi
• parasites
• pollution
• toxins

because when we are young the body develops a tolerance and learns what not to attack and what to attack

• 1. Extra cellular bacteria, parasites, fungi
• 2. intracellular bacteria, parasites
• 3. viruses (intracellular)
• 4. Parasitic worms (extracellular)

• examples: streptococcus pneumoniae, clostridium tetani, trypanosoma brucei, pneumocystis carinii
• Diseases: pneumonia, tetanus, sleeping sickness, pneumocystis pneumonia

• Mycobacterium leprae (leprosy), Leishmania donovani (leishmaniasis)
• Plasmodium falciparum (malaria)

• Variola (smallpox)
• Influenza (flu)
• Varicella (chickenpox)

• Ascaris (ascariasis)
• Shistosoma (Shistosomiasis)

• 1. Innate immunity (nonspecific mechanisms)
• 2. Adaptive Immunity (specific mechanisms)

• 1. rapid response (hours)
• 2. fixed (always there and protects against all different kinds)
• 3. limited number of specificities
• 4. constant during response

• Skin (keratin protects)
• Mucous membranes

Antibodies

• 1. slow response (days to weeks)
• 2. variable (immunity increases with number of exposures) - booster shots
• 3. numerous highly selective specificities
• 4. improve during response (memory)

• 1. first line defenses
• 2. phagocytosis
• 3. inflammation

Structures, chemicals, and processes that work to prevent pathogens from entering the body (skin and mucous membranes).

Multiple layers of tightly packed cells defer most pathogens from penetration. Shedding of dead skin cells removes microorganisms. Epidermal dendritic cells phagocytize pathogens.

Collagen fibers help skin resist abrasions that could introduce microorganisms.

Chemicals that defend against pathogens. Perspiration secreted by sweat glands has salt, which inhibits the growth of pathogens. Antimicrobial peptides act against microorganisms. Lyzsozyme destroys cell wall of Gram (+) bacteria. Sebum secreted by glands helps keep skin pliable and less likely to break or tear and loweres skin pH to a level inhibitory to many bacteria.

Epithelial cells are tightly packed to preven the entry of pathogens. Continual shedding of cells carries away microorganisms.

produces and drains tears, blinking spreads tears and washes surface of the eye. tears contain lysozymes.

they compete with potential pathogens, they consume the nutrients so that there aren't any left for pathogens, they create an unfavorable environment, they stimulate the body's second line of defense, they promote overall health by providing vitamins

Normal microbiota are competing with potential pathogens

• they are present in the skin, mucous membranes, and neutrophils
• -induce holes in bacterial membranes
• -intracellular killing

when pathogens penetrate the skin or mucous membranes

• 1. Phagocytic cells (blood and tissues)
• 2. Nonspecific chemical defenses against pathogens
• -complement proteins (serum)
• -antimicrobial peptides (all body secretions)
• -interferons (3 types)
• 3. Inflammation (fever)

natural antiviral mechanisms that every cell in our body contains

mostly water containing electrolytes, dissolved gases, nutrients, and proteins

the fluid remaining when clotting factors are removed. it includes iron-binding compounds, complement proteins, and antibodies

• Cells and cell fragments.
• 1. erythrocytes
• 2. platelets
• 3. leukocytes (divided into granulocytes and agranulocytes)

the formation and development of cells of the blood

• –Basophils – stain blue with basic dye methylene blue
• –Eosinophils – stain red/orange with acidic dye eosin
• –Neutrophils – stain lilac with mix of acidic and basic dyes

• –Phagocytize pathogens
• –Capable of diapedesis (Chemotaxis)