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The mucosal immune response

Mucosal tissues are major barriers to the entry of pathogens into the body. The IgA (and sometimes IgM) antibodies in mucus and other secretions can bind to the pathogen, and in the cases of many viruses and bacteria, neutralize them. Neutralization is the process of coating a pathogen with antibodies, making it physically impossible for the pathogen to bind to receptors. Neutralization, which occurs in the blood, lymph, and other body fluids and secretions, protects the body constantly. Neutralizing antibodies are the basis for the disease protection offered by vaccines. Vaccinations for diseases that commonly enter the body via mucous membranes, such as influenza, are usually formulated to enhance IgA production.

Immune responses in some mucosal tissues such as the Peyer’s patches (see [link] ) in the small intestine take up particulate antigens by specialized cells known as microfold or M cells ( [link] ). These cells allow the body to sample potential pathogens from the intestinal lumen. Dendritic cells then take the antigen to the regional lymph nodes, where an immune response is mounted.

Iga immunity

This diagram shows the process in which cells of the small intestine generate IgA immunity.
The nasal-associated lymphoid tissue and Peyer’s patches of the small intestine generate IgA immunity. Both use M cells to transport antigen inside the body so that immune responses can be mounted.

Defenses against bacteria and fungi

The body fights bacterial pathogens with a wide variety of immunological mechanisms, essentially trying to find one that is effective. Bacteria such as Mycobacterium leprae , the cause of leprosy, are resistant to lysosomal enzymes and can persist in macrophage organelles or escape into the cytosol. In such situations, infected macrophages receiving cytokine signals from Th1 cells turn on special metabolic pathways. Macrophage oxidative metabolism is hostile to intracellular bacteria, often relying on the production of nitric oxide to kill the bacteria inside the macrophage.

Fungal infections, such as those from Aspergillus , Candida , and Pneumocystis , are largely opportunistic infections that take advantage of suppressed immune responses. Most of the same immune mechanisms effective against bacteria have similar effects on fungi, both of which have characteristic cell wall structures that protect their cells.

Defenses against parasites

Worm parasites such as helminths are seen as the primary reason why the mucosal immune response, IgE-mediated allergy and asthma, and eosinophils evolved. These parasites were at one time very common in human society. When infecting a human, often via contaminated food, some worms take up residence in the gastrointestinal tract. Eosinophils are attracted to the site by T cell cytokines, which release their granule contents upon their arrival. Mast cell degranulation also occurs, and the fluid leakage caused by the increase in local vascular permeability is thought to have a flushing action on the parasite, expelling its larvae from the body. Furthermore, if IgE labels the parasite, the eosinophils can bind to it by its Fc receptor.

Questions & Answers

ഫസ്റ്റ് ചാപ്റ്റർ ഇംപോർട്ടൻസ് പോസ്റ്റ്
Reshma Reply
Yes....
Loving
nhi samjh aya
Anshika
Nhi wt is this
Loving
I don't know
Anshika
Okk wre frm u r
Loving
what is mean of? reshma
Asad
D bone in d ankle joint re what ?
Ifunanya Reply
can one define a cell as a basic unit of a living organism
Michael Reply
Which of the following hormones are responsible for the adolescent growth spurt? estrogen and testosterone, even in women?
Kepa Reply
estrogen
Farhana
Estrogen!
Jazil
estrogen hormone
Michael
yes estrogen hormone
Anshika
yes
Sale
What is sling give d characteristics of sling uses of sling
adamu Reply
a sling a rope used in hunting ie throwing of rocks
Michael
I went to learn anatomy of joints
Arman Reply
me 2
adamu
joint have 3 cartilaginous joint fibrous joint synovial joint U can reserch in Google can explain U well
sopheaktra
define sling
adamu
To throw with a circular or arcing motion
real
what is respiration
Osele Reply
what is respiration
Paul
Respiration is the process by which oxygen is taken in and carbon dioxide is given out.
Md
Respiration is the combination of inhalation and exhalation.
Khim
inhalation is the taking in air from environment to lung and exhalation is taking out sir from the lung to environment ..
Khim
is the process by wich gases(oxygen and carbon(IV)oxide go through the nose, trachea and the lungs to the blood stream
Michael
what is holistic
Kibrom Reply
Holistic means encompassing the whole of a thing, and not just the part. Holistic medicine looks at the whole person for answers, not just at physical symptoms. You might have heard of holistic medicine, which tries to treat someone as mind and body, instead of treating only the part of the patient
I want to learn one by one system like skeleton system... muscular system
Mary Reply
i want to learn this
Kibrom
what is the difference between regional anatomy and system anatomy
David
system anatomy is when we study the system like digestive, circulatory, reproductive, but regional anatomy is studying the anatomy by regions of body like anatomy of neck, thorax, head etc. Regional anatomy may include system anatomy...
Biplav
yes
Anshika
explain in details factors that affects bone development
Precious Reply
describe the process of bone healing
Precious
out line factors that delays bone healing
Precious
actually,for the bone formation they must be sufficient level of calcium,phosphorus and vitamin D in the body for it to happen smoothly.
lucky
the above mentioned substances are the ones able for the formation and repairing of bones.
lucky
explain in details factors that affects bone development
Precious
what are tissue
muki Reply
a lots of cells make tissue and a cell body is tissue
Rabab
cells come together to form a tissue and tissues come together to form an organ
Adoma
what is appendicular skeleton
OSE Reply
appendicular skeleton is upper limbs and lower limbs
sopheaktra
what is decompression sickness?
Japhar Reply
It occurs in Scuba divers when they rise too quicky to the sea surface , their oxygen tanks have oxygen mixed with N2 gas which has a high solubility at sea level , when the diver rises the N2 gas bubbles out of plasma and this causes Air Ebolism
Siphiwesihle
if a single part if Nervous system doesn't function like synapse? what will occur
Lilian Reply
no transmission of impulses no respond cause mechanical damage
Komolika
what happens when calcium ion channel is blocked
Jachike
a MORAH /MORAH
Kechi
meaning?
Jachike
transmission of impure
sopheaktra
when calcium ion channels block . lightheadedness Low blood pressure. Slower heart rate. Drowsiness. Constipation. Swelling of feet ankles and legs. Increased appetite. Gastroesophageal reflux disease (GERD
sopheaktra
I'm not sure about it
sopheaktra
low blood pressure
Anshika
what is this substance
Peng Reply
In the human body, there are no atoms as separate entities. Instead, they constantly interact with other atoms to form and break down more complex materials. To fully understand anatomy and physiology, you must understand how atoms are involved in such interactions. The key is to understand the beha
Warid
what are functions of muscle cell
Veronicah
please can someone help with ten functions of the following hormones 1.Gastrin 2. Adrenal sex hormone 3. Secretin 4. Follicle Stimulating Hormone 5. Glucagon 6. Progesterone
Har
4.produces the oetrogen and bursts open to release egg cells.
Komolika
5.regulates the level of glucose in the blood and it is secreted when glucose low in the blood.
Komolika

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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