Unit 4 BMS Exam Missouri State

What are the lines of defense?

barriers to entry: physical and chemical

• skin and mucous membranes and chemical secreted

innate immunity (less specific)

• phagocytic leukocytes

• complement proteins

• inflammation

• fever

Adaptive immunity

• antibody mediated immunity

• B cells 

• Antigens 

  • anything that antibody will bind

  • cell mediated immunity

    • T cells 

what is the first line of defense?

Intact skin

linings of body cavities and tubes

chemical barriers to infection

not considered part of the immune system

• skin, mucous membrane, mucous, hairs, tears, saliva, uriine, defecation, and vomiting

• sebum, lysozyme, gastric juices, vaginal secretions

• normal bacterial “flora” intestines

What is immunity?

the body’s overall ability to resist and combat something not itself

innate immunity

What is adaptive immunity triggered by? What is it?

the innate immunity

• changes with exposure

• antibodies specific to a particular pathogen

  • WBC proliferate and respond

• 1-2 weeks to develop 

  • memory of cells left behind allow for a more rapid response to next pathogen appearance

  • IgG- immunoglobulin gamma 

What is an antigen?

Something an antibody will bind to

What is the difference between innate and adaptive?

Innate

• immediate

• 1000 presence receptros 

• nonself chemical cues on or in pathogens 

Adaptive 

• 7-10 days 

• vast number of receptors 

• antigens of pathogens. toxins, proteins

• LONG TERM

What is a pathogen?

something that causes disease

• fungus, bacteria, protozoa, viruses, prions

What is a disease?

a disorder of structure or function especially one that produces specific signs or symptoms or that affects a specific location and is not simply a direct result of physical injury

• diseases have

  • specific location

  • clinical sign: measured

  • symptom: IE stomach ache

  • not a direct result of physical injury

What are the different kinds of cells and what do they function as?

Granulocytes (neutrophils, eosinophils, basophils) are involved in the rapid, innate immune response, while agranulocytes (lymphocytes, monocytes) are crucial for the specific, long-term adaptive immune response. Granulocytes work by releasing cytotoxic agents, while agranulocytes function by producing antibodies (lymphocytes) and engulfing pathogens and presenting antigens to trigger an adaptive response (monocytes). 

A granulocytes include monocytes and lymphocytes 

• monocytes include dendritic and macrophages and bridge the gap between the innate and adaptive immune system

• lymphocytes include B and T cells 

What is a fever?

A systemic response to a local infection

What are bacteria?

2-3 billion species on earth and less than 0.5 percent cause disease in human

• are treated by antibiotics

• bacteria enter the body

• multiply

• produce toxins- virulence factors that harm the hosts cells 

  • poke holes in cells

  • degrade tissues

  • prevent protein synthesis

  • cause cell death

What are viruses?

Contain genetic information- DNA or RNA in a protein coat and may have a lipid coat

use the host cells replication machinery to multiply

NOT ALIVE

What are prions?

misfolded proteins

presence of prion causes properly folded proteins or unfold and refold in the wrong shape

NOT ALIVE

• Bovine spongiform encephalopathy: Mad cow

• Creutzfeldt-Jakob Disease, Kuru: humans 

• scrapie: sheep

• chronic wasting disease: deer

What is a fungus?

Eukaryote

doubling time of hours

How are pathogens spread?

• direct contact

• bodily fluids- blood, feces, saliva, semen, vaginal fluid, other

• contaminated water, food, drink

• from soil

• inhaling droplets from air

• contact of pathogen with mucous membrane

• contact of pathogen with open wound

What are nosocomial infections?

hospital infections

What is the immune system?

Defesive and counter attacking system

attempts to prevent/stop invasions of pathogens causing disease

What are the two systems to defend against pathogens?

Nonspecific (or innate) immunity

• inborn

• same defenses regardless of the pathogen

Specific (or adaptive) immunity

• part is inborn- part develops over course of life

• a specific attack against a specific pathogen

What is the second line of defense?

Internal chemical and cellular defenses

• innate immune system: interferons (signal protein that alerts nearby cells) and the complement system (a group of blood proteins that are activated in a cascade to fight infection and inflammation)

• fever, inflammation (basophils and mast cells) and phagocytes (neutrophils and macrophages)

What is the interraction between microbes and humans?

microbes in our environment

• body 

• used to make many foods ( food micro)

• used to make drugs (pharmaceutical micro)

• used to recycle nutrients (decomp) and clean up waste (environmental micro)

• some cause diease in humans (medical micro)

What are different kinds of antigens made of?

proteins, lipids, oligosaccharides

What is the lymphatic system?

Functions 

• picks up fluid lost from the capillaries an returns it to the blood

• defense against pathogens 

•       production, maintenance, and distribution of lymphocytes in the body

• lymphatic capillaries in small intestine absorb fats 

Lymph is the fluid in lymphatic vessels

• tonsils are lymph nodes

• when infection occurs, proliferation of WBCs and causes tenderness in lymph vessels

What are the primary and secondary lymphoid organs?

primary organs:

• Red bond marrow: produce WBCs and B cell mature in bone. more in children

• Thymus galnd: where some WBC mature and is not needed when older

  • bilobed gland above heart

  • largest in children

  • T cells mature here from bone marrow and most stay here

Secondary organs

• spleen 

  • white(produce lymphocytes and antibodies) and red pulp (blood filtering)

  • Contain B, T and Macrophages 

  • upper left region of abdominal cavity (under stomach)

• lymph nodes 

  • small oval shaped structures along lymph vessels

  • contain B T and macrophages

  • common in neck, armpits and groin

What does the lymphatic system do summed up?

• drain excess interstitial fluid

• delivery

  • to blood stream

  • lymph nodes

• disposal

  • phagocytosis of pathogens

• lymph capillaries

  • in all tissues

  • contain openings

  • merge into larger vessels that contain smooth muscles and valves

• Fluid moves due to skeletal muscle contraction like veins 

What is the integumentary system?

skin is part of the first line of defense

• integument

  • protection(water loss, infection, trauma)

  • maintenance of homeostasis (body temp)

  • sensory

  • synthesis of chemicals (melanin and vitamin D)

• Accessory organs include sebaceous glands, sweat glands, hair, and nails

• CONTAINS THREE LAYERS CALLED THE EPIDERMIS< DERMIS, and HYPODERMIS 

What is the epidermis made of and its funciton?

Made of keratinized, stratified squamous epithelium

• keratinocytes- make keratin (water insoluble substance)

  • outermost layer is dead keratinocytes- nonspecific defense

• Melanocytes: makes melanin: role in skin color

• langerhands cells: defense cells

• granstein cells- Control immune system ( dentritic cells)

Also arrector pilli make hair stand up to create a layer of still air close to skin

What is the dermis?

Dense irregular connective tissue

• Elastin and collagen fibers 

blood vessels and nerve ending 

sebaceous and sweat glands 

hair follicles and nails l

What is the hypodermis?

subcutaneous layer and is the layer beneath the dermid

• specialized loose connective tissue (adipose)

• fat: used as insulatory and cushion

What are mucous membranes?

Provide nonspecific immunity

• made of epithelium

• line any cavity open to exterior

• Mouth

  • digestive tract

  • resp tract

  • urinary tract

  • reproductive tract

Secreted by some of the epithelial cells called goblet cells 

• mucous slows down pathogens by trapping

• and this mucous with pathogens is moved out of the body

What do chemical barriers do?

When physical fails, chemical barriers aid

• include

  • sebum or oil from sebaceous glands 

    • acidic and antimicrobial

  • Perpiraition, tears, saliva

    • contain enzyme called lysozyme, a natural antibacterial chemcial 

  • Gastic acid: extremely low pH killing most pathogens

  • Urine and vaginal secretions

    • acidic

  • normal bacterial microbes 

    • outcompete other microbe and protect against harmful pathogens 

What is the second line of defense

phagocytes: WBC that engulfs and destroys foreign agens 

phagocytosis: engulfing foreing material or substances by specialized WBC

Macrophages: Phagocytic WBC that engulfs anything detected as foreign: some trigged by APC

What is the play by play of innate immunity in action?

• pathogen enters the body

  • macrophages arrive

    • release cytokines  (chemical messages) which cause inflammation 

• Complement system now activated

  • attract other phagocytes

  • bind to the pathogen

  • forms the membrane attack complex

    • makes hole in cell wall

  • trigger inflammation

EFFECTIVE AGAINST BACTERIAL INFECTIONS NOT VIRAL

What is inflammation?

Form of positive feedback

Fast and general response to tissue infection or damage

Histamine is release by Mast cells (basophils in the skin) from breaking open from trauma

• cause vasodilation and capillaries are more permeable (lead out fluids causing edema and pain due to pressure)

Increased blood flow causes warmth and redness

• may inhibit some pathogens 

increased blood flow brings more leukocytes 

• neutrophils are the first to damage- phagocytosis 

Neutrophils release cytokines to calle for more leukocytes including macrophages

• Chemotaxis: movement or organism or cell due to chemical stimuli

What are the key indicators of inflammatioin?

Heat, redness, swelling, pain, and Loss of Function

What happens in the second line of defense with a viral infection?

Interferons

• interfere with viral infection by attacking virally infected cells 

Signal released by a virus infected cell

• bind to receptors on nearby uninfected cells 

• inhibit protein synthesis and cause RNA degredation

  • neighboringWhat is  cell is now resistant to viral infection

What is a fever?

defined as a change in the body’s temperature set point

results in an elevation of basal body temperature above 37 degrees celcius or 98.6

proteins called pyrogens reset the body’s thermostat ot a higher temp

• macrophages release interleukins (pyrogens)

• stimulate the brain to release prostaglandins- lipid based

  • rise the temps set point 

• increase metabolism to support immune cells 

• fevers above 42 degrees C or 107 F are medical emergency

How does a fever harm pathogens directly and indirectly?

prevents growth at higher temps

aids defensive mechanisms by raising the metabolic rate

Elecated temperature: enzymes repair processes work faster, cells move more quickly, and specific immune cells are mobilized more rapidly

What is the third line of defense?

Adaptive or acquired immunity

specific defenses

• protects against a specific pathogens 

• protects against cancer

• dependent on B and T cells (lymphocytes)

  • Recognition or self V nonself

  • specificity: each B and T cell makes receptors for one kind of antigen

  • diversity: B and T cells collectively may have receptors more more than 2 Billion antigens 

  • Memory: some B and T cells first formed held in reserve for future needs

How to lymphocytes become specialized for different roles?

Effector cells: respond immediately

Memory cells: Set aside for a second or third encounter

Plasma cells: make antibodies 

What are the two types of effector T cells?

Helper T cells: used in both responses and use signaling to help with B, T, and Macrophages

cytotoxic T cells: Killer T cells: produced in the bone marrow and go the the thymus gland for development. Part of cell mediated immunity

What are the two methods for combating pathogens in the third line of defense?

Antibody mediated ( or humoral) acquired immunity 

• B lymphocytes create disease fighting compounds called antibodies 

Cell- mediated (cellular) acquired immunity

• t lymphocytes directly attack pathogen containing cells through direct cell-to-cell contact

What do the different types of lymphocytes do?

B cells: produced in bone marrow, sent to lymphatic system

• produce antibodies: antibody mediated immunity

Cytotoxic  (Killer) T cells 

• produced in bone marrow and go to the thymus gland for development 

• cytotoxic T cells: cell mediated immunity 

Helper T cells

• used in both types of responses

What are MHC complexes?

Major histocompatability genes code for these proteins

• some of these proteins stick out of cell membranes 

• T cells have receptors that recognize them

Lymphocytes have receptors on their cell membranes 

• detect the exact antigen

Each lymphocyte receptors are specific to only one antigen

• will ignore all others

What are antigen presenting cells?

The include macrophages and dendritic cells (phagocytic cells)

Enzymes break antigen into pieces 

pieves join with the MHC markers (antigen-MCH complexes) and move to plasma membrane

Helper T cell binds, release cytokines 

• B and T cells activated in large numbers

Helper T cells can bind and release cytokines and stimulate proliferation

Plasma cells make more antibodies 

What are the important aspects of antibodies?

shape of antibodies

diversity and specificity or antibody mediated immunity

Binding of antigens

How are B cells activated?

When antibodies bind, B cells divide

Helper T cells produce cytokinds

B cell descendants become memory B cells or plasma cells (effector B cells) and release thousands of antibodies

What happens after antibodies bind to antigens?

neutralization- clumping of microbes- stick to antigens- activate complement system- cells lysis

clumping of microbes and sticking to antigens enhances phagocytosis 

What are immunoglobulins and the different types

proteins produced by B cells- various shaped Antigen binding sites: other sites with special roles

types 

Ig M: first formed in newborns and first infection

IgD: found on the surface of immature B cells

IgG: Main antibody in circulation

IgA: found in milk and saliva

IgE: parasitic infection and allergic response

Responses by antibodies can’t reach threats _________ cells 

inside cells like infected cells

What does an APC do?

presents an antigen to a t cell

• helper T cells and cytotoxic T cells 

Tragets: viruses, bacteria, some protozoa and some fungi and cancerous cells

What do cytotoxic T cells do to attack target cells?

release perforins

Cytotoxic T cells have vacuoles containing granzymes and perforins 

• these perforins punch holes in target cells 

• followed by granzymes that cause the cell to undergo apoptosis

What are natural killer cells?

Some T lymphocytes differentiate into NK cells

• attack virus- infected cells and tumor cells, killing through cell to cell contract

NK are acturally a part of the nonspecific immune response 

they remove all foreing of infected cells in the same way

they make holes in cells thus killing them

• similar mechanism is used by cytotoxic T cells 

They do not respond to immunization or produce clones of memory cells

What are the two types of immunity? What are the two types of immunity for each of these situations?

ability to combat disease

• natural immunity- through an infection

• artificial immunity: through medical intervention

two sub categories

• active immunity: makes own antibodies (natural infection arfiticial vaccine)

• passive immunity: given prepared antibodies

What is immunological memory?

• Memory cells provide many years of immunity to a pathogen

• effector cells form during primary immune response

  • memory T and plasma cells form during a second adaptive response

  • memory cells determined by the type of antigen exposure

What is the advantage of active immunity?

it creates memory cells

• produced during primary response remain in the body for years until the same antigen reappears- start secondary response

• second response is faster because immune system only needs to stimulate the specific memory cells

What is active immunization?

Vaccine first injection+ booster shot

• killed or extremely weakened pathogens

• inactive forms of natural toxins

• transgenic viruses

What is passive immunization?

injections of purified antibodies

How does the covid vaccine work?

A small portion of the spike protein gene is introduced into you cells and the cell then reads that sequence to build the spike protein

your cell breaks down the spike protein into fragments and then presents on its surface

The mRNA introduced from the vaccine is later destroyed by the cell

when vaccinated cell dies, it will leave behind debris from the spike protein

that debris can then be engulfed by an antigen presenting cell and presents on the cell membrane

the APC presents the spike protein to helper T cells which then raises the alarm for fighting infection

Activated B cells will start to divide and pour out antibodies to target the spike protein on the surface of the coronavirus

APcs can also activate killer T cells to seek out and destroy the infected cells which are displaying the spike protein on their surface

What are allergies?

Harmless substances that provoke an immune attack

Common allergens 

• pollen

• variety of foods and drugs

• dust mites

• fungal spores

• insect venom

• ingredients in cosmetics

What is anaphylactic shock

whole body allergic response in the blood stream and can be fatal with extreme vasodilation.