Lab Exam 3 Flashcards
(174 cards)
1
Q
Protists are informally grouped as…
A
- “animal like” protozoans: non photosynthetic & alway unicellular
- “plant like“ algae: photosynthetic & can be unicellular or multicellular
- “fungus like“ water molds : aka plankton
2
Q
Plankton and type of plankton:
A
- microorganisms that drift or float in water, moved by currents
- zooplankton: motile and non-photosynthetic
- phytoplankton: photosynthetic
3
Q
General characteristics of Protozoa
A
- they are eukaryotic cells
- they are unicellular
- they are non photosynthetic & heterotrophs
4
Q
Trophozoites
A
- this is what protozoans are called during the feeding and growth part of their life cycle
5
Q
Holozoic Protozoans
A
- ingest whole food particles through phagocytosis
6
Q
Saprozoic Protozoa
A
- ingest small soluble food molecules
7
Q
Three main types of protozoa
A
- paramecium
- amoeba
- euglena
8
Q
Cell structures seen in Paramecium
A
- cilia for locomotion/movement
- cytoproct for removing waste
- cystosome for ingesting food
- contractile vacuole used for osmotic regulation and removing excess water
9
Q
Cell structures seen in Euglena
A
- flagellum for locomotion/movement
- endoplasm
- ectoplasm
- contractile vacuole used for osmotic regulation and removing excess water
10
Q
Entamoeba histolytica disease (Protozoa) and Giardia lamblia
A
- transmitted by cysts in feces
- primary cause of amoebic dysentery
- drinking contaminated water
11
Q
Naegleria fowleri
A
- notorious “brain eating amoeba”
- parasite found in warm, freshwater
- causes primary amoebic meningoencephalitis (PAM)
12
Q
Acanthamoeba
A
- causes keratitis a.k.a. corneal inflammation and blindness
13
Q
Trypanosoma brucei
A
- causes African trypanosomiasis or sleeping sickness
- colonizes the blood, and the brain after being transmitted through the bite of a Tsetse fly
- symptoms include confusion, difficulty, sleeping, lack of coordination
- fatal, if left untreated
14
Q
Trypanosoma Cruzi
A
- cause American trypanosomiasis
- Chagas’ disease
15
Q
General Characteristics of fungi
A
- have cell wall material made of chitin
- contain ergosteral in plasma membrane
- so body made up of filaments called Hyphae
16
Q
Purpose of Hyphae
A
- makes a mass called mycelium ( in fungi ) which forms the thallus/body of fleshy fungi
17
Q
Types of Hyphae
A
- coenocytic - lack walls and cell membranes between the cells
- septate - have walls between the cells
- pseudohyphae - cells that stick together as a short chain, a result of budding yeast producing asexually
18
Q
Fungal Dimorphism
A
- able to appear as yeasts or molds, which can be important for infectivity. They are capable of changing their appearance in response to environmental changes such as nutrient availability or fluctuations in temperature, growing as a mold, for example, at 25 °C (77 °F), and as yeast cells at 37 °C (98.6 °F). This ability helps dimorphic fungi to survive in diverse environments. Two examples of dimorphic yeasts are the human pathogens Histoplasma capsulatum and Candida albicans.
19
Q
Algae
A
- autotrophic protists that can be unicellular or multicellular
- responsible for the production of approximately 70% of the oxygen and organic matter in aquatic environments
- normally grow in only aquatic or extremely moist environments
20
Q
Different types of algae
A
- dinoflagellates: when dense can form toxic red tide/algal blooms
- diatoms: made of silica (a form of glass) & produce sexually and asexually
- golden algae
- brown algae
- red algae
- green algae
21
Q
Red algae:
A
- source for agar, agarose, and carrageenan, solidifying agents used in laboratories and in food production
22
Q
Lichen
A
- a combination of two organisms: a green alga or cynobacteria and fungus
- can be found on almost any service, especially rocks and other plants (epiphytes)
- Slow growing and can live for a long time
23
Q
Crustose Lichens
A
- tightly attached to the substrate, giving them crusty appearance
24
Q
Foliose Lichens
A
- have leaf like lobes
- they only be attached at one point in the growth form
- they also have a second cortex below the medulla
25
Fruticose Lichens
* have rounded structures and overall branched appearance
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Five structures of Lichen from top to bottom
* cortex
* algal zone
* medulla
* lower cortex
* rhizines
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general characteristics/structure of viruses
* infectious , acellular pathogens
* they are obligate intracellular, parasites with host and cell type specificity, meaning they enter through a specific route
* do not have a wide range, typically only infect specific hosts and only specific cell types within hosts
* lack genes
* have DNA or RNA genome, never both
* genome is surrounded by a protein capsid or phospholipid membrane
* capsid is composed of protein, subunits called capsomeres
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Mechanical transmission of Virus
occurs when the AnthroPod carries a viral pathogen on the outside of its body and transmit it to a new host by physical contact
* example of fly landing on a burger, and human eating the burger
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Biological transmission of Virus
* occurs when the AnthroPod carries the viral pathogen inside its body and transmit it to the new host through biting
* example mosquito biting a human
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Zoonoses and Reverse Zoonoses
* zoonoses: when a virus is transmitted from an animal host to a human host for example, the avian influenza virus or originating in birds, but can cause disease in humans
* reverse zoonoses: from human host to animal host
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Enveloped Virus
* viruses formed with a nucleic acid packed capsid surrounded by a lipid layer
* spikes are used to attach: adsorption
* causes hemagglutination
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Non-enveloped viruses
* also called naked viruses
* formed from only a nucleic acid and capsid
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Bacteriophage Virus
* targets bacteria
* consists of capsid, viral genome, sheath, tail fibers
* spider like structure
* often sprayed on meats
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Virus Identification
* biochemical tests cannot be used
* cytopathic effects: distinct observable cell abnormalities due to viral infection
* serological tests: used to detect the presence of certain types of viruses in pay
* nucleic acid amplification test: used in molecular biology to detect, unique, nucleic acids of viruses inpatient samples
35
Serological Tests
* the most common
* detect antibodies against viruses in a patient
* uses antibodies to identify viruses in neutralization tests, viral hemagglutination, and Western blot
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Reproductive cycle of viruses
* lytic cycle
* lysogenic
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Lytic Cycle
* bacteriophage takes over the cell, reproduces new phages, and destroys the cell
* has 5 stages
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Five stages of lytic cycle
* attachment
* penetration
* biosynthesis
* maturation
* lysis
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Attachment stage
* 1st stage of infection
* phage interacts with specific bacterial surface receptors
* phage attaches by tail fibers to host cell
* specificity of the reaction between viral protein and host receptor defines and limits the host species
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Penetration stage
* 2nd stage of infection, aka uncoating
* coat of envelopes viruses may rise with the host cell membrane and release the viral capsid into the host cytoplasm
* enter the cell by “endocytosis”
* release of the viral genome from its protective capsid
* nucleic acid will be transported within the cell and transcribed to form new progeny virions
*** viral DNA enters the host cell
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Biosynthesis Stage
* 3rd Stage of infection
* messenger RNA is transcribed from viral DNA
* codes for viral proteins that are translated by the host cell
* nucleic acid replication produces new viral genomes for incorporation into progeny virions
* DNA viruses replicate mainly in the nucleus
* RNA viruses mainly in the cytoplasm but there are exceptions (Pox viruses contain DNA but replicate in the cytoplasm of the host cell)
*** phage DNA replicates and phage proteins are made
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Assembly Stage
* assembly of viral nucleocapsids may take place in the nucleus (ex: herpes virus, adenovirus)
* in the cytoplasm (ex: polio virus)
* at the cell surface (ex: budding viruses such as influenza)
*** new phage particles are assembled
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Release Stage
* Release of the new infectious viruses is the final stage
*** the cell lyses, releasing the newly made phages
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Lysogenic Cycle
* The viral DNA becomes integrated into the bacterial DNA after infection.
* It is replicated along with the host DNA when the host reproduces.
* The viral DNA is referred to as a prophage.
* environmental factors will trigger the prophage to begin a lytic cycle.
45
Has both lytic and lysogenic cycles
* temperate bacteriophage
* A temperate bacteriophage has both lytic and lysogenic cycles. In the lysogenic cycle, phage DNA is incorporated into the host genome, forming a prophage, which is passed on to subsequent generations of cells. Environmental stressors such as starvation or exposure to toxic chemicals may cause the prophage to be excised and enter the lytic cycle
46
Prophage
* integrated phage genome (genome of a bacteriophage)
* occurs in lysogenic cycle when phage genome integrates into the bacterial chromosome and becomes part of the host
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Provirus
* similar to prophage refers to the integrated of any virus, including retroviruses which infect animals
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DNA and RNA Virus (retrovirus)
* The host cell must synthesize a DNA copy of the RNA before it can be transcribed or translated
* The HIV virus is a retrovirus
* HIV enters a human cell, it releases its RNA and an enzyme called reverse transcriptase
* Makes a DNA copy of the HIV RNA using reverse transcriptase
* The resulting HIV DNA is integrated into the infected cell’s DNA
* HIV is called a retrovirus referring to the reversed (backward) process
49
HIV Virus
* enveloped icosahedral retrovirus
* when HIV-infected cell divides, it makes a new copy of the integrated HIV DNA as well as its own genes
* the HIV DNA copy is either Inactive (Latent) or Activated
50
Reverse Transcriptase
* an enzyme that synthesizes a complementary ssDNA (cDNA) copy using the +ssRNA genome as a template. The ssDNA is then made into dsDNA, which can integrate into the host chromosome and become a permanent part of the host. The integrated viral genome is called a provirus.
* in other words, it’s used to make a cDNA from a small amount o
Converts RNS to DNA
Occurs in retroviruses
51
HIV mode of replication in humans
* HIV fuses to the host cell surfaces
* HiV RNA, reverse transcriptase, integrate and other viral proteins enter the host cell
* Viral DNA is formed by reverse transcription
* Viral DNA is transported across the nucleus the nucleus and integrates into the host DNA
* New viral RNA is used as genomic RNA and to make viral proteins
* New viral RNA and proteins move to the cell surface and a new, immature HIV forms
* The virus matures when protease releases the proteins that form the mature HIV
52
HIV, which cells are targeted
* CD4+ T Cells
* aka a type of white blood cell
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Signs
*Changes in a body that can be measured or observed
* examples: fever, low blood pressure (these are measurable)
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Symptoms
* changes in body function that are felt by the patient as a result of disease
* examples: pain, fatigue, weakness (these are not measurable)
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Asymptomatic or Subclinical disease
no noticeable signs or symptoms
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Syndrome
* a specific group of signs and symptoms that accompany a disease
* example: AIDS, Down Syndrome
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What is an infectious diseases
* caused by the direct effect of a Pathogen
* there are many types of infectious disease (contagious, communicable, iatrogenic, etc)
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Contagious Disease
* is easily and rapidly spread from one host to another
* example: flu
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Communicable disease and examples
* spread from person to person through either direct or indirect mechanisms
* some can be contagious
* example: measles or gonorrhea
60
Non-communicable disease and examples
* a disease that is not transmitted from one infected host to another
* example: tetanus and legionnaires
* you could get it from drinking contaminated water
61
Iatrogenic disease and examples
* contracted as the result of a medical procedure/treatment
* can occur after procedures involving wound treatments, catheterization, or surgery if the wound or surgical site becomes contaminated
* example: necrotizing fasciitis the “flesh eating disease” or Clostridium Perfringens
62
Nosocomial disease and examples
* acquired in hospital setting
* can be transmitted easily via improperly sterilized medical equipment, bed sheets, call buttons, door handles, or by clinicians, nurses, or therapists who do not wash their hands before touching a patient
* example: pneumonia
63
Noninfectious disease and examples
* noncommunicable infectious diseases not caused by pathogens
* example: cholera (comes from water)
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Zoonotic Disease and examples
* transmitted from animals to humans
* example: rabies, yellow fever, Rocky Mountain/Rickettsia Rickettsii
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5 periods/stages of a disease
* incubation period
* prodromal period
* period of illness
* period of decline
* period of convalescence
66
Incubation Period
* 1st stage of disease
* interval between initial infection and first signs and symptoms; pathogen begins multiplying
* pathogen begins multiplying in the host, but there are insufficient numbers of pathogen particles present to cause symptoms of disease
* NO SYMPTOMS ARE PRESENT
67
Prodromal Period
* 2nd stage of disease
* short period after incubation; early, mild symptoms; pathogen continues to multiply, host starts to react
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Period of disease
* 3rd stage of disease
* disease is most severe and at its peak
* signs and symptoms of disease are most obvious
69
Period of decline
* 4th stage of disease
* signs and symptoms subside, # of pathogens particles decrease
* person may become susceptible to developing secondary infections because of their weakened immune system
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Period of Convalescence
* 5th stage of disease
* body returns to its pre-diseased state and back to normal functions for the majority
* no pathogens
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Chronic disease
* Symptoms develop slowly; pathologic changes can occur over longer time spans (months, years, or a lifetime)
* example: cancer, HIV, hepatitis, gastritis/helicobacter
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Latent disease
* causal pathogen goes dormant for extended period of times with no active replication, but then activates and produces symptoms
* example: herpes & chicken pox
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Acute disease
* symptoms develop rapidly, but the disease lasts only for a short time
* example: influenza
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ID 50
* an indicator of virulence
* median infectious dose
* the number of pathogens required to cause active infection in 50% of inoculated populations
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LD50
* an indicator of virulence
* median lethal dose
* a number of pathogens or amount of toxin required to kill 50% of inoculated populations
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Stages of Pathogenesis
* exposure: pathogen makes contact
* adhesion: pathogen attaches to the cells
* invasion: dissemination of pathogen throughout local tissues or the body
* infection: successful multiplication of pathogen
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Portals of entry
* anatomic site through which pathogen can pass into host tissue
* nose (MOST COMMON)
* eye
* mouth
* placenta, vagina, urethra, anus
* broken skin, needle, insect bite
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Parenteral route portal of entry
* deposited directly into tissues when skin barrier is penetrated
* wounds, insect bites, animal bites, needle pricks can provide a parenteral portal of entry for microorganisms
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Adhesin/adherence
* proteins or glycoprotein found on the surface of a pathogen that attaches to receptors on the host cell
* example: E. Coli bacteria on human urinary bladder cells
* found on bacterial, viral, fungal, and protozoan pathogens
* EPS substance helps with adherence
* glycocalyces capsule helps with adherence
* spikes help with adherence
* adhesin found on Fimbriae help with adherence
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Fimbriae
hair like protein bristles on the cell surface
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What are exoenzymes?
Also known as extracellular enzymes which enable pathogens to invade host cells and deeper tissues
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Exoenzyme Collagenase
* Digests collagen in connective tissue to promote spreading
* produced by C. perfringens
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Exoenzyme Hyaluronidase
* digest polysaccharides (hyaluronic acid) that hold cells together in connective tissue
* increases spreading of infection by allowing the pathogen to pass through the tissue layers and disseminate
* produced by staphylococcus aureus, streptococcus pyogenes, and clostridium perfringens
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Exoenzyme Kinases
* digests fibrin clots formed by the body to isolate the infection
* produced by staphylococcus aureus, streptococcus pyogenes
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Exoenzyme Coagulase
* coagulates/clots blood
* fibrin clot may protect the bacterium from phagocytosis
* produced by staphylococcus aureus
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Exoenzyme IgA protease
* destroys IgA antibodies (critical in mucosal immunity)
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Infection (local, focal, systemic)
Successful multiplication of the pathogen
* local infection: pathogens are limited to a small area of the body
* focal infection: a localized, pathogen, or the toxins it produces, can spread to a secondary location
* systemic/generalized infection: and infection disseminated throughout the body
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Primary versus secondary infections
* primary infections: acute infection that causes the initial illness
* secondary infections: opportunistic infection after a primary (predisposing) infection
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Toxins produced by bacteria
* endotoxins: present inside a bacterial cell and is released when the cell disintegrates
* Exotoxins: proteins produced and secreted by bacteria
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Gram -
* gram-negative bacterial pathogens release endotoxins
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Gram +
* majority of gram-positive bacterial pathogens release exotoxins
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Endotoxins
Endotoxin
* source: gram-negative
* relation to microbe: outer membrane
* chemistry: lipid A lipopolysaccharides
* fever? Yes.
* neutralized by anti toxin? No
* LD50: relatively large (good thing)
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Exotoxins
Exotoxins
* source: mostly gram-positive
* relation to microbe: byproducts of growing cell
* chemistry: protein
* fever?: No.
* neutralize by antitoxin? Yes.
* LD50: small (bad news/dangerous, even if you get a small amount, you will be infected)
* are easier to contain due to thick peptidoglycan layer in cell wall
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Bacteremia, toxemia, viremia, septicemia
Bacteremia: bacteria in the blood
Toxemia: toxin in the blood
Viremia: virus in the blood
Septicemia: bacteria are both present and multiplying in the blood
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Shock
A life-threatening decrease in blood pressure that prevents cells in organs from receiving enough oxygen and nutrients
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Membrane disrupting toxins
* leukocidins - kills WBCs
* Hemolysins - kills RBCs
* Streptolysins - hemolysin disrupting phospholipid bilayer
Directly target the cell membrane
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Intercellular
* toxins secreted by pathogens that directly affect targets inside host cells
* A common mechanism involves AB toxins, where a binding subunit (B) attaches to the cell surface, and an active subunit (A) is translocated into the cell, where it exerts its enzymatic effects on intracellular targets
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Superantigens
* cause an intense immune response due to release of cytokine from host cells
* overstimulation of host immune system - distracts body from the pathogen
* excessive cytokines in blood causes fever, nausea, vomiting, diarrhea, shock, and death
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Types of exotoxins and examples
* intracellular targeting
* membrane disrupting toxins
* superantigens
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Exotoxin mode of activity
1) superantigens that bind to surface receptors and stimulate intracellular signaling,
2) membrane-damaging toxins that directly disrupt cell membranes, and
3) intracellular effector toxins that translocate into the cell and modify intracellular target
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Portals of Exit
* respiratory tract
* gastrointestinal tract (feces & saliva)
* genitourinary tract (urine & vaginal secretions
* skin to skin
* blood
* needles or syringes
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Toxin
poisonous substances produced by microorganisms that assist in their ability to invade and cause damage to tissues
103
Toxigenicity
ability of a microorganism to produce a toxin to cause damage to host cells
104
Intoxications
presence of toxin without microbial growth
105
Pathogenicity
ability of a microbial agent to cause disease
106
Virulence
the degree to which an organism is pathogenic
* less virulent pathogens are more likely to result in mild signs and symptoms of disease or be asymptomatic
* highly virulent pathogens will almost always lead to a disease state, some may cause multi-organ and body system failure
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Avirulent
not harmful
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Epidemiology
* John Snow is the father of epidemiology
* focuses on containing the spread of disease
* microbiology greatly contributed to epidemiology
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Incidence
number of people who develop a disease (new cases) at a particular time period
110
Prevalence
number of people who develop a disease at a specified time, regardless of when it first appeared (both new and existing cases)
111
Sporadic
disease that occurs only occasionally in a population (prevalence is zero)
112
Epidemic
disease acquired by many people in a given area in a short time (increasing incidence)
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Endemic
disease constantly presents in a population (never zero prevalence)
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Pandemic
worldwide epidemic (high worldwide incidence)
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Modes of Disease Transmission
Reservoirs and Carriers
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Reservoirs
* Reservoirs: continual sources of infection
* Living Reservoirs: aka human reservoirs (AIDS & gonorrhea)
* Animal Reservoirs: zoonoses (Rabies & Lyme Disease)
* Nonliving Reservoirs: Soil and Water (Tetanus & Cholera)
117
Carriers
* Carrier: individual capable of transmitting a pathogen without displaying symptoms
* Passive Carrier: contaminated with the pathogen and can mechanically transmit it to another host (without being infected)
* Active Carrier: is an infected individual who can transmit the disease to others (may or may not exhibit signs or symptoms)
* Asymptomatic Carrier: active carriers who do not present signs or symptoms of disease despite infection
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Direct contact / person-to-person transmission
* Requires close association between the infected and susceptible host
119
Types of Direct Contact Transmission:
* Vertical Transmission: pathogens are transmitted from mother to child during pregnancy, birth, or breastfeeding
* Horizontal transmission: often, contact between mucous membranes
* Droplet Transmission: transmission via airborne droplets (travel less than 1m from the reservoir to the host)
120
Indirect Contact Transmission
* spread to a host by a nonliving object called a fomite
* touching contaminated surfaces that have been in contact with and infected person
* example: doorknobs, towels, surgical equipment, etc
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Vehicle Transmission
* transmission by an inanimate reservoir
* through water, food, or air
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Vector Transmission
* Arthropods, especially fleas, ticks, and mosquitoes
* can be transmitted through mechanical transmission or biological transmission
* mechanical: infected fly lands on food
* biological: infected mosquito bites
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Emerging diseases
* diseases that are new, or increasing in incidence, or showing a potential to increase in the near future
* most are zoonotic, of viral origin, and likely to be vector-borne
* Example: Ebola
124
Reemerging diseases
* diseases increasing in frequency after a previous period of decline
* causes: changing conditions, old prevention regimes that are no longer working
125
Nonspecific vs Specific Defenses
* nonspecific: do not target any specific pathogen, rather they defend against the wide range of potential pathogens
126
Innate
* built-in mechanisms of the human organism
* what we are born with
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Nonspecific Innate Defenses
* provide an immediate or rapid response against potential pathogens
* however on occasions, they can cause damage to the body contributing to the signs and symptoms of infection
128
Three lines of defense against pathogen
* physical defense barriers: skin and mucous membranes
* chemical defense barriers: inflammation, fever, and antimicrobial substances
* cellular defense barriers: phagocytosis
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Features of the Skin
* physical defense
* composed of three layers; upper layer epidermis, second layer dermis, and hypodermis which lies beneath the dermis
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Keratin
* A protective protein
* makes the skin's surface mechanically, tough, and resistant to degradation by bacterial enzymes
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Epidermis
* top layer
* thinner portion made of tightly packed epithelial cells containing keratin
* dead cells of epidermis are frequently shed, along with microbes
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Dermis
* inner, thicker portion made of connective tissue and blood vessels
* contains hair, follicles, sweat, glands, nerves, and blood vessels
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Hypodermis
* lies beneath the dermis
* layer of fatty tissue
* contains blood and lymph vessels
134
Mucous Membrane
* physical nonspecific defense
* lines, the nose, mouth, lungs, and urinary and digestive tracts
* consist of a layer of epithelial cells bound by tight junctions
* epithelial cells secrete a moist sticky substance called mucus (containing antimicrobial peptides) which covers and protects the more fragile cells, trapping debris and microbes
* the debris like microbes, dust, mold, spores, are trapped in the mucus lining in the respiratory tract upon respiration
135
Mucociliary Escalator
* transports microbes trapped in mucus away from the lungs
136
Nonspecific Chemical Barrier
* Antimicrobial peptides
* Complement action
* Cytokines
* Short peptides
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Short Peptides
* have broad spectrum antimicrobial properties
* produce the routine lead by the body
* produced/produced in greater quantities in response to the presence of an invading pathogen
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Antimicrobial peptides (AMP)
* inhibit cell wall synthesis
* form pores in the plasma membrane
* destroy DNA and RNA
* broad spectrum of activity
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Complement system/activation
* plasma protein mediators consisting of protein circulating in blood serum
* assist the immune system in destroying microbes
* proteins are designated with uppercase C (C1-C9) and are in active until they are split into fragments (products)
* activated fragments are indicated with lowercase a and b
* C3 splits into C3a and C3b
140
Outcomes of complement activation
* Cytolysis: activated complement proteins, create a membrane attack complex
* Opsonization: promotes attachment of the phagocyte between microbe (C3b coat the surface of microbe, flagging it for phagocytosis
* Inflammation: stimulated by complement proteins C3a and C5a
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C3 splits into
* C3a and C3b
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Cytokines and their Action
* are soluble proteins that act as communication signals between cells
* induce the release of inflammation eliciting mediators (including histamines prostaglandins, leukotrienes, bradykinin)
143
Autocrine, paracrine, and endocrine
* their actions describe which cells are targeted by cytokines, and how far the cytokines must travel to bind to their intended target cells’ receptors
144
Types of cytokines
* Interleukins
* Chemokines
* Interferons
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Interleukins
* one of the three types of cytokines
* modulator of immune response
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Chemokines
* one of the three types of cytokines
* chemotactic factors that recruit leukocytes to the sites of infection, tissue damage, and inflammation
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Interferons
* one of the three types of cytokines
* produced by cells infected by viruses; have antiviral activity
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Granulocytes
* leukocytes with granules in their cytoplasm
* neutrophils, basophils, and eosinophils
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Agranulocytes
monocytes and lymphocytes
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Neutrophils
* nucleus multilobed
* most abundant
* first responders
* phagocytic
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Basophils
* nucleus is comma shaped
* releases histamine
* works in allergic response responses
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Eosinophils
* Bilobed nucleus
* phagocytic
* toxic against parasites and helminths
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Monocytes
* largest white blood cells
* differentiate into tissue specific phagocytes called macrophages and dendritic cells
* highly phagocytic
* provide bridge between innate and adaptive immune responses
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Macrophages
* a differentiation of monocytes
* developed characteristic, suited to the particular tissue
* provided me in protection for the tissue in which they reside
* support, normal function of neighboring tissue cells through the production of cytokines
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Dendritic Cells
* a differentiation of monocytes
* important sentinels residing in the skin and mucous membranes (which are portal of entry for many pathogens)
156
Lymphocytes
* include Natural Killers which play an important role in non-specific innate immune defenses
* also include B cells and T cells
* destroy cells in an abnormal way
* cancer
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Inflammation features
* inflammation, is triggered by a cascade of chemical mediators and cellular responses when cells are damaged and stressed or when pathogen successfully breached the physical barriers of the innate immune system
* five signs associated with inflammatory response: erythema (redness), edema (swelling), heat, pain, altered function
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Natural Killer Cells
* referred to as a lymphocyte
* bind to abnormal target cell
* release perforin creates pores in the target cell
* release granzymes/proteases that entered through the pores into the target cells cytoplasm
* leads to apoptosis
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Mast Cells
* similar to basophils
* however everyone like basophils, they leave the circulating blood and are more frequently found residing in tissues
* also promote inflammatory responses
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Process of Phagocytosis
* recognition
* engulfment of a pathogen
* formation of a phagosome
* digestion of the pathogenic particle in the phagolysosome
* expulsion of undigested materials from the cell
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Cellular Defenses
* Tears, sweat, urine, etc
* Erythrocytes (red blood cells/RBC’s)
* leukocytes (white blood cells/WBC)
* Thrombocytes (platelets)
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Innate immunity
defenses against any pathogen; rapid and present at birth
163
Adaptive immunity:
immunity or resistance to a specific pathogen; slower to respond, has memory component
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Immunity
ability to ward off disease
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Susceptibility
lack of resistance to disease
166
Phagocytes
cells whose main function is to seek, and chest, and kill pathogens
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Vasoconstriction
* narrowing of blood vessels
* occurs immediately after injury
* cause shivering and raise in body temp
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Vasodilation
* widening of blood vessels
* due to release of histamine from resident mist cells
* dilute toxins, and bacterial products at the site of injury or infection
* can be caused by inflammation and low body temp
169
Valley fever
Coccidioides immitis
170
Candida albicans
Responsible for vaginal and yeast infections
171
T. Brucei
AFRICAN SLEEPING DISEASE
172
T. Cruz I
Chagas’ disease
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