MicroBio Test 3 Chapters 13-18

What are the first lines of defense

* Physical barriers
* Antimicrobial substances
* Normal microbiota

What are the body’s physical barriers

* Skin
* Mucous membranes

What are some antimicrobial substances

salt accumulation from perspiration

Gastric juices

Lysosomes that degrade peptidoglycan

antimicrobial peptides

What is normal microbiota

Harmless microbes, commonly found in an organism. excluding pathogens

what happens as a result to excess antibiotic usage

normal microbiota can be disrupted which can predispose people to infection

What are the components of blood

* plasma
* thrombocytes
* erythrocytes
* leukocytes

types of leukocytes

* granulocytes
* mononuclear phagocytes
* lymphocytes

types of granulocytes

* neutrophils
* eosinophils
* basophils

functions and characteristics of neutrophils

* release substances that trap and destroy microbial invaders
* most abundant leukocyte in blood

function and chracteristics of eosinophils

* release chemicals that destroy eukaryotic parasites
* found in tissues below the mucous membrane

functions and characteristics of basophils

* releases histamine and other inflammatory chemicals

types of mononuclear phagocytes

* monocytes
* macrophages
* dendritic cells

functions and characteristics of of monocytes

* phagocytosis
* differentiate into either macrophages or dendritic cells

functions and characteristics of macrophages

* important type of sentinel cell for phagocytosis

functions and characteristics of dendritic cells

* collect antigens from the tissue and bring them to lymphocytes that gather in secondary lymphoid organs

types of lymphocytes

* B cells
* T cells
* Innate lymphoid cells

function and characteristics of B cells

* participate in the adaptive response of the body
* mature in the bone marrow

function and characteristics of T cells

* participate in the adaptive response of the body
* mature in the thymus

function and characteristics of innate lymphoid cells

* participate in the adaptive responses
* found in lymphoid organs
* differing roles based on differing locations

What are surface recepters

* span the outside of the membrane
* connect the outside of the cell to the inside

what are cytokines

* cells that bind to appropriate receptors to induce changes
* effects are either local, regional, or systemic

types of cytokines

* interferons (regulation of immune response)
* interleukins (T and B cells)
* chemokines (chemotaxis)

what are adhesion molecules

* molecules that allow cells to adhere to other cells

what are pattern recognition receptors

* receptors that are on the cell surface, internal membranes, and in the cytoplasm
* detects signs of microbial invasion.
* allows for the production of cytokines

What is a complement system

* a group of serum proteins that are activated n a cascade
* cause inflammation, opsonization, and lysis of foreign cells

what are the steps of phagocytosis

* chemotaxis
* recognition and attachment
* engulfment
* phagolysosome formation
* destruction and digestion
* exocytosis

what is the inflammatory response

* the body’s response to damage by microbes, chemicals, or physical agents
* causes blood vessels to dilate to increase blood flow
* characterised by swelling, redness, heat, and pain

what is fever

* an abnormally high body temperature
* due to bacterial or viral infection
* inhibits the growth of pathogens

What is an antigen

* any substance that is recognised as foreign to the body
* triggers the immune response(antibody generator)

what is an antibody

* glycoproteins produced by the body in response to an antigen
* provide protection from antigens

classes of antibodies

* IgM
* IgG
* IgA
* IgD
* IgE

properties and functions of IgM

* first antibody produced during the primary response
* produced in response to T-independent antigens
* neutralize viruses and toxins, immobilize motile organisms and prevent microbes from adhering t cell surfaces
* binding to antigen leads to activation of complement system

properties and functions of IgG

* most abundant class in the blood and tissues
* provides long term protection
* facilitates phagocytosis, leads to activation of the complement system, and allows antibody-dependent cellular cytotoxicity
* antibody that is transported across the placenta from mom to baby in utero

properties and functions of IgA

* most abundant class produced
* secreted into mucus, tears, and saliva, providing mucosal immunity
* neutralizes viruses and toxins in mucous membranes
* component of breast fed babies, protects the intestinal tract of breast fed babies

properties and functions of IgD

* involved in the development and maturation of antibody response

properties and functions of IgE

* Binds via the Fc region to mast cells and basophils
* allows cells to detect parasites
* involved in many allergic reactions

what is clonal selection

the process in which lymphocyte antigen receptors bind to an antigen

what is clonal expansion

process after antigen binding occurs that allows the lymphocyte to multiply and differentiate into plasma and memory cells

what is humoral immunity

* produced by antibodies
* mediated by B lymphocytes
* respond to extracellular antigens

what is the primary immune respone

* immune response that occurs during first exposure to an antigen

what is the secondary immune response

* immune response that occurs after the second exposer to an antigen

what is cell-mediated immunity

* response to intracellular antigens
* mediated by T lymphocytes

types of T cells

* cytotoxic T cells (induces apoptosis in target cells)
* Helper T cells (activates target cells)

What are natural killer cells

* cells that induce apoptosis in infected host cells

what is mutualism

the relationship between host and microbe when both partners benefit

what is commensalism

the relationship between host and microbe when one partner benefits and the other is unharmed

what is parasitism

the relationship between host and microbe when one benefits at the expense of the other

what are the principles of infectious disease

* colonization
* infection
* noticeable impairment
* pathogenicity
* Characteristics of infectious disease
* course of infectious disease

what is colonization

the establishment and multiplication of an infection

what are the types of infection

* subclinical infections
* secondary infections
* primary infections

what is a subclinical infection

an infection with mild or no symptoms

what is a primary infection

the initial symptoms of an infection

what us a secondary infection

an infection that occurs in addition to the first infection

what is noticable impairment

* signs and symptoms

what are symptoms

* subjective effects of infection
* (pain, nausea, etc.)

what are signs

* objective evidence of infection
* (rash, swelling, pus formation, etc)

what are the types of pathogenicity

* primary pathogens
* opportunistic pathogens
* virulence
* virulence factors

what are primary pathogens

pathogen that causes disease a healthy individual

what are opportunistic pathogens

when the body's defenses are compromised or when introduces to an unusual condition

what is virulence

the degree of pathogenicity of an organism

what are virulence factors

factors that allow microorganisms to cause disease

what are the characteristics of infectious disease

* communicable or contagious
* infectious dose

what are communicable or contagious diseases

infectious diseases that spread from one host to another

what are infectious doses

the number of microbes necessary to cause infection

what is the course of infectious disease

* incubation period
* illness
* convalescence

what is the incubation period

the time between infection and the onset of symptoms

what is illness

the signs and symptoms of disease

what is convalescence

the healing and recovery of disease

what are carriers

people that harbor and spread disease

what does the suffix -emia mean

* “in the blood”

what is adherence

* when adhesions(located at the tips of pili), attach to receptors(capsules or cell wall proteins)

what is colonization

* multiplication and establishment of infection

what are type 3 secretion systems

* injectisomes
* syringe-like microbes that inject proteins into eukaryotic cells

what are the mechanisms that pathogens use to enter the body

* Skin(hard for pathogens to enter.)- enter through open injuries or open wounds
* Mucous membranes(entry point for most pathogens)

what are the mechanisms that bacteria use to avoid the immune system

* hiding within the host cell to avoid complement proteins, phagocytes, and antibodies
* complement system proteins
* avoiding antibodies

what are exotoxins

* soluble poisonous protein substances secreted by microorganisms

what are endotoxins

* poisonous substances, often bacterial cell wall components

what do cytotoxins do

damage cells(diptheria)

what do neurotoxins do

damage nervous system(botulinum)

what do enterotoxins do

damage intestinal lining(choleragen)

what do erythrogenic toxins do

damage red blood cells(streptococcal)

what is the damage associated with inflammation

Enzymes and toxic components released by phagocytes

what is the damage associated with adaptive immunity

immune complexes settle in kidneys and joints

how do viruses and eukaryotes avoid the immune system

* binding to host cells and invasion requiring specific receptors
* avoiding interferons to block the expression of host genes or block enzyme activation

what is hypersensitivity

* an allergy or heightened immune response to an antigen

what is an allergen

* an antigen that causes an allergy

what is type 1 hypersensitivity

* immediate IgE-mediated sensitivity
* (anaphylactic shock, hay fever, hives, etc.)

what is type 2 hypersensitivity

* cytotoxic; transfusion reaction, hemolytic disease of newborns

what is type 3 hypersensitivity

* immune complex-mediated; complexes arise from infections by microorganisms
* (farmer’s lung, serum sickness, etc.)

what is type 4 hypersensitivity

* delayed cell-mediated, tuberculin reaction, contact dermatitis, and transplant rejection
* (poison ivy and poison oak)

what is an autoimmune disease

the result of an immune reaction against one’s own tissue

5 types of autoimmune disease

* type 1 diabetes(pancreas)
* graves disease(thyroid)
* rheumatoid arthritis(joints)
* lupus(blood vessels)
* myasthenia gravis(muscles)

what is an immunodeficiencies

lack of sufficient immune response

what is a primary immunodeficiency

* results from a genetic defect or environmental factors that impair B cells, T cells, natural killer cells, phagocytes, or complement system

what is a secondary immunodeficiency

* occurs as a result of infection or other stresses from advances age, pregnancy, immunosuppressive drugs, radiation, or malnutrition

what is natural active immunity

* self acquired immunity by exposure to disease-causing agents

what is artificial active immunity

* immunity self-acquired by vaccination

what is natural passive immunity

* immunity acquired by exposure to disease-causing agents by one organism and passed onto another

what is artificial passive immunity

* immunity acquired by vaccination in one organism and passed onto another organism

what is herd immunity

* the phenomenon that occurs when a critical concentration of immune hosts prevents the spread of an infectious agent