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Another inflammatory mediator, bradykinin , contributes to edema , which occurs when fluids and leukocytes leak out of the bloodstream and into tissues. It binds to receptors on cells in the capillary walls, causing the capillaries to dilate and become more permeable to fluids.

  • What do the three complement activation pathways have in common?
  • Explain autocrine, paracrine, and endocrine signals.
  • Name two important inflammation-eliciting mediators.

Part 2

To relieve the constriction of her airways, Angela is immediately treated with antihistamines and administered corticosteroids through an inhaler, and then monitored for a period of time. Though her condition does not worsen, the drugs do not seem to be alleviating her condition. She is admitted to the hospital for further observation, testing, and treatment.

Following admission, a clinician conducts allergy testing to try to determine if something in her environment might be triggering an allergic inflammatory response. A doctor orders blood analysis to check for levels of particular cytokines. A sputum sample is also taken and sent to the lab for microbial staining, culturing, and identification of pathogens that could be causing an infection.

  • Which aspects of the innate immune system could be contributing to Angela’s airway constriction?
  • Why was Angela treated with antihistamines?
  • Why would the doctor be interested in levels of cytokines in Angela’s blood?

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[link] provides a summary of the chemical defenses discussed in this section.

Chemical Defenses of Nonspecific Innate Immunity
Defense Examples Function
Chemicals and enzymes in body fluids Sebum from sebaceous glands Provides oil barrier protecting hair follicle pores from pathogens
Oleic acid from sebum and skin microbiota Lowers pH to inhibit pathogens
Lysozyme in secretions Kills bacteria by attacking cell wall
Acid in stomach, urine, and vagina Inhibits or kills bacteria
Digestive enzymes and bile Kill bacteria
Lactoferrin and transferrin Bind and sequester iron, inhibiting bacterial growth
Surfactant in lungs Kills bacteria
Antimicrobial peptides Defensins, bacteriocins, dermicidin, cathelicidin, histatins, Kill bacteria by attacking membranes or interfering with cell functions
Plasma protein mediators Acute-phase proteins (C-reactive protein, serum amyloid A, ferritin, fibrinogen, transferrin, and mannose-binding lectin) Inhibit the growth of bacteria and assist in the trapping and killing of bacteria
Complements C3b and C4b Opsonization of pathogens to aid phagocytosis
Complement C5a Chemoattractant for phagocytes
Complements C3a and C5a Proinflammatory anaphylatoxins
Cytokines Interleukins Stimulate and modulate most functions of immune system
Chemokines Recruit white blood cells to infected area
Interferons Alert cells to viral infection, induce apoptosis of virus-infected cells, induce antiviral defenses in infected and nearby uninfected cells, stimulate immune cells to attack virus-infected cells
Inflammation-eliciting mediators Histamine Promotes vasodilation, bronchoconstriction, smooth muscle contraction, increased secretion and mucus production
Leukotrienes Promote inflammation; stronger and longer lasting than histamine
Prostaglandins Promote inflammation and fever
Bradykinin Increases vasodilation and vascular permeability, leading to edema

Key concepts and summary

  • Numerous chemical mediators produced endogenously and exogenously exhibit nonspecific antimicrobial functions.
  • Many chemical mediators are found in body fluids such as sebum, saliva, mucus, gastric and intestinal fluids, urine, tears, cerumen, and vaginal secretions.
  • Antimicrobial peptides (AMPs) found on the skin and in other areas of the body are largely produced in response to the presence of pathogens. These include dermcidin, cathelicidin, defensins, histatins, and bacteriocins.
  • Plasma contains various proteins that serve as chemical mediators, including acute-phase proteins , complement proteins , and cytokines .
  • The complement system involves numerous precursor proteins that circulate in plasma. These proteins become activated in a cascading sequence in the presence of microbes, resulting in the opsonization of pathogens, chemoattraction of leukocytes, induction of inflammation, and cytolysis through the formation of a membrane attack complex (MAC) .
  • Cytokines are proteins that facilitate various nonspecific responses by innate immune cells, including production of other chemical mediators, cell proliferation, cell death, and differentiation.
  • Cytokines play a key role in the inflammatory response, triggering production of inflammation-eliciting mediators such as acute-phase proteins, histamine , leukotrienes, prostaglandins , and bradykinin .

Fill in the blank

________ are antimicrobial peptides produced by members of the normal microbiota.

bacteriocins

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________ is the fluid portion of a blood sample that has been drawn in the presence of an anticoagulant compound.

plasma

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The process by which cells are drawn or attracted to an area by a microbe invader is known as ________.

chemotaxis

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Short answer

Differentiate the main activation methods of the classic, alternative, and lectin complement cascades.

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What are the four protective outcomes of complement activation?

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Questions & Answers

pls someone should help with ANTIMICROBIAL MNEMONICS
Shuaib Reply
Aminoglycosides: Charasteristics of Aminoglycosides Nymonics; (AMINO)  Active against Aerobic gram negative Organisms Mechanism Of resistance is by Modifying enzymes Inhibit protein synthesis by binding to 30s ribosomal subunit Nephrotoxic Ototoxic Members  Of Aminoglycosides: Nymonics: (ST
Najeebul
Please can some briefly describe the germ theory?
Michael Reply
hyy all
Shuaib
pls someone should help with ANTIMICROBIAL MNEMONICS
Shuaib
which drug can be used to treat gonococus?
Lambon Reply
Madication - Antibiotic " and Gonorrhoea can be treat with Antibiotic
Maryam
Penicillin -An antibiotic
Michael
Ciprofloxacin tablets also an antibiotic
Michael
Ofloxacin is also antibiotics
Ikenna
yes
Elli
sory no fot gonococus
Elli
what are eukaryotes
Kakande Reply
eukaryotes simply refers to a cell who does not have a definite nucleus.
Franca
Eukaryotic cell has a true nucleus
arfa
what is right answer ?
krishna
I can remember now truly that eukaryotes have true nucleus.I was referring to procaryotes.
Franca
Eukaryotes have got true nuclues
Ede
they have a nucleus, larger than prokaryotes
Alanna
The eukaryotes cell are found in advance organisms.
Franca
Eukaryotes are multicellular organism which has a membrane bounded structure mostly found in animals and some plant cells
KINGSFORD
bacteria growth curve
sani Reply
No bacteria's don't grow curvey. Curve is a shape for a bacteria not growth
KINGSFORD
What is the difference between eukaryotes and prokaryotes?
KINGSFORD Reply
What's a multicellular organism?
KINGSFORD
multicellular organisms is an organism composed of many cells which are to varying degree integrated and independent.
Ruth
Boiling of milk to kill germs is called?
Kasigwa
pasteurization
Aiyedun
pasteurization
Katta
kadha
Katta
pasteurization
Gomathi
what is microscopic
monish
Pasteurization
Hosy
what are Flora
Hosy
you mean like the normal flora?
Tenucharity
pasteurization has to do with killing of the harmful microbes present for safe consumption. Eg. pasteurized yoghurt beside the bacteria that are supposed to be present, there may be harmful ones that have been killed
Tenucharity
Can someone explain flora
KINGSFORD
what is cell?
Anita Reply
the cell is the functional and structural unit of the body
Ruth
yes ur right
Kasigwa
who add me
Wali
hy
Katta
hy
Shivangi
basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life.
Haru
hi
Ruth
hi
Haru
coming Oct 2 I have a exam on microbiology
Haru
okay all the best
Ruth
hi
sachin
hi
Ruth
plz bro send question of microbiology
umesh
structural and functional unit of the life
monish
this is not the correct answer
Alanna Reply
why
Hayat
why not
Zaajid
what is the correct answer?
vannessa
where is question
Zaajid
ask you question
Zaajid
What are mitochondria
Hayat
what is mitochondria
Hayat
who is the father of microbiology
T-
not
Hayat
Antonie Van Luweenhoek
Ravikumar
Mitochondria is the powerhouse of the Cell. And is the cell organelle which helps cell in generation of energy by Cellular Respiration
Ravikumar
Mitochondria are threadlike structuresbounded by double membrane,and serves as the power house of the cell
Felicity
can I get notes on introduction to microbiology just started I have no idea please
rita
Mitochondria is a membrane bounded structure, it's sausage in shape and has inner and outer membrane. The inner membrane is folded at the surface called cristae which project to form matrix. They function as the power house for the cell.
KINGSFORD
Rita are you a medilab student?
KINGSFORD
the father of microbiology is Luis pasture
Able
Erythromycin--------(+++) Cefuroxine ------------(++++) Chloramphenicol --(++) Vancomycin ---------(++++) please what does the above result means. under urine culture and sensitivity?
Kwame
francesco redi was the first to challenge spontaneous generation not pasteur
Alanna
Rita are you a medilab student? no please am a public health student
rita
kwame Evans this result ll mean that the bacterial in the urine can be remedy / killed by this antibacterial (cefuroxime and the rest are antibiotics
rita
Rita Appiah thanks.
Kwame
contact backstage
Emmanuel
what is a vacual
Star Reply
What is microbiology
Nji Reply
it is the study of microscopic organisms and basically their relation to the environment
Tenucharity
what is elements
Erneet Reply
an Element is a substance that can not be further decomposed by ordinary chemical means.
vannessa
can i get notes of biochemistry
Sneha Reply
yep why not
Abdullah
what is microbiology?
Gayanjali Reply
what is malaria
Gayanjali
bios- life/living things micro- small things that cannot be seen with the naked eye In other words the study of living things that cannot be seen with the naked eye but with the help of a microscope
Coltuneac
logos- science
Coltuneac
it is 10 to the power minus 6 biology which studies life forms on those scales including metabolism , physiology, nutrition requirements
barun
what are prokarytes
NDIMUKIKA Reply
A prokaryotic is a unicellular organanism that lacks a membrane bound nucleus ,mitochondria or other any membrane bound organelle. .......
Maryam
in prokaryotic nucleus is not developed and cell organelles are absent
Harshad
how is one who is feeling blockage in the chest with mucus be diagnosed
Essy Reply
be talking sepitol every morning
Ikenna
is that all?
Ven.phumie
Practice MCQ 5

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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