THE INFLAMMATORY RESPONSE
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- Опубликовано: 20 май 2019
- The inflammatory response is initiated within hours of infection or wounding and is characterized by edema, or swelling, heat, redness, and pain at the site of an infection or injury. These characteristics reflect four changes in local blood vessels.
1. The heat and redness during inflammation is the result of an increase in vascular diameter. The increase in vascular diameter also results in slower blood flow.
2. There is an increase in vascular permeability. During inflammation, endothelial cells have gaps between them - fluid from the blood exits and accumulates in local tissues, resulting in edema and pain. The fluid contains plasma proteins such as complement proteins and mannose binding lectin, which aid in defending against pathogens.
3. Endothelial cells, which line the walls of blood vessels, are “activated” during inflammation. That is, endothelial cells express cell-adhesion molecules that promote the binding of circulating leukocytes, otherwise known as white blood cells.
4. There is clotting in the microvessels at the site of infection, which prevents pathogens from spreading via the blood.
The purpose of the inflammatory response is threefold:
1. Allows the body to defend itself from invading microorganisms. The increase in vascular diameter, along with the activated endothelial cells, results in leukocytes being able to attach to the endothelium, and then migrate into the tissues where they can attack pathogens. This process of leukocytes leaving the bloodstream and entering tissues is called extravasation.
2. Induces local blood clotting, and this creates a physical barrier preventing the infection from spreading into the bloodstream.
3. Promotes the repair of injured tissue.
The state of inflammation is set up when tissues are physically damaged, or when pathogens are recognized by macrophages and later by other white blood cells. These circumstances induces the release of a variety of inflammatory mediators which cause the inflammatory response. Macrophages and neutrophils secrete prostaglandins, leukotrienes, and platelet-activating factor (PAF), which are lipid mediators of inflammation.
Then, macrophages secrete cytokines, which are substances released by cells of the immune system that affect other cells. One kind of cytokine are chemokines, which act as chemoattractants. Chemokines cause directed chemotaxis. Chemokines direct phagocytes to move towards the source of the chemokines, which are the sites where they are needed.
Two cytokines important to the inflammatory response are C5a and Tumor Necrosis Factor-α , or TNF-α. C5a stimulates respiratory burst, which is the rapid release of reactive oxygen species. It attracts neutrophils and monocytes. It also increases vascular permeability, increases expression of adhesion molecules on the endothelium, and causes local mast cells to release granules containing the inflammatory molecule histamine, and TNF-α. TNF-α is a potent activator of endothelial cells.
Activation of endothelial cells is central to the inflammatory response. Cytokines produced by macrophages, especially TNF-α, cause endothelial cells to externalize granules called Weibel-Palade bodies containing P-selectin within minutes of pathogen detection by macrophages. P-selectin appears on the surfaces of local endothelial cells. Selectins are one of three structural families of adhesion molecules important for leukocyte recruitment, with the other two being intercellular adhesion molecules (ICAMs) and leukocyte integrins. Later, within 2 hours of pathogen detection, the endothelial cells express mainly E-selectin. Shortly after P-selectin gets to the cell surface, mRNA encoding E-selectin is synthesized. Both selectins interact with the sulfated sialyl-LewisX that is present on the surface of neutrophils.
Once inflammation has begun, neutrophils make up the first wave of cells that cross the blood vessel wall to enter an inflamed tissue. After this, monocytes cross the blood vessel wall and differentiate into tissue macrophages. In later stages of inflammation, other leukocytes such as eosinophils and lymphocytes also enter the infected site. Usually, leukocytes travel in the center of small blood vessels, where blood flow is fastest. However, in inflamed tissues, the slower blood flow allows leukocytes to interact in large numbers with the endothelial cells lining the blood vessels.
In addition, injury to blood vessels triggers two enzyme cascades - the kinin cascade and the coagulation cascade. The kinin system consists of plasma proteases. The eventual result of this cascade is the production of several inflammatory mediators, including bradykinin, a vasoactive peptide that increases vascular permeability and causes pain. Pain makes you aware of the problem and causes you to immobilize that part of your body, helping prevent the spread of infection. The coagulation system is another protease cascade whose activation leads to formation of a fibrin clot.
Best but concise video available!! Taking Patho for my NP program and this helped me tremendously while studying for midterms 🙏🏾
I am in an Immunology class at the moment and this video cleared some things up as in the E- selectin. thanks a lot
That video was fantastic! wow, I’ve tried to find a good, short, and concise video on inflammation for a while now… this was definitely the best… thank you!
cheers dude. i'm in year 12 and don't need such detail although i'm grateful because other people do and i am glad that you didn't rush through the cells. Also great art for the video, if you made them yourself then you are a mad lad, since i am an artist and know how hard it is. Keep up the good work man!!!
This is brilliant thank you!!!! The visuals were so easy to follow and helped understand the process.
omggggg thank u i'm in a Human Pathology class and had no idea what was going on. it's completely online and the professor just assigns reading assignments, no videos, nothing. as i was watching this video a lot of things started connecting. i remembered most things from the textbook but seeing it in a video made it so much easier and i feel more confident on my understanding on inflammation.
There was a fantastic amount of information packed into these 6 minutes! Thank you for creating!
nah yeah this is an amazing video - everytime i listen to it i pick up a new fact - it's jam packed full of really useful detail - thankyou !
This was incredibly helpful, thank you!
You have done a good job!
Wow, beautifully illustrated and clearly explained. Thank you
Fantastic video, thank you!
Such a great video!
This is cool! Thank you for this well-explained video! Now I understand!! Thank you!!!
This guy!! You are amazing!
A very simple explanation enriched with images that complement the speech. I congratulate you, my students will be very grateful to you.
Very good explanation it covered summary of veterinary or medical inflammation topics
Very good
The personification of blood clotting through the use of Gandalf really sold it for me 👌👌👌
I love this! Worth subbing for.
Thank you very much
Amazingly explained
thank you so much for this
I got a deep cut today in. My palm waiting for this inflammatory stage😔😬thank you for this wonderful video to understand the process
This is by far the best video about inflammation i've ever seen. Thank you!
the fantastic visual aspect of it all helped me so much and made everything so much easier! thank you !!
Great Content.
Well done
Great vid
Elaborative 💯🙌
Perfect 🤩
This is a really good explanation of inflammation.
thank you for this ....it was soooooo helpful
Thank you
I’m going through the Inflammatory Response now, so thank’s for the explaining
Can you see it? Like a vapor?
@@SusieSynth well no I can’t see it because the damage is from my stomach unlike in the video
thank you so much for the well-explained video, it had helped me to understand it. :)
Same
excellent video 🖤
Man, I saw lots of medical videos about this topic , but your video is the best without dubs
Thank you so much ^_^
True
God bless you
Hi there, you state that the increase in vascular diameter results in a slower blood flow. The resources I have state that vasodilation actually increases blood flow but reduces blood pressure. I'm interested to hear your thoughts!
The blood flow increases in volume, however, it decreases in velocity. So we have large volumes of blood moving at a slow rate. Hope that's helpful.
I may be wrong but its more blood moving at a slower rate
Magic. Got it.
U rock dude ! Appreciate it!
Very thorough. Had to reverse a number of times because of the speed of which the information was taught. Just rolling down the interstate in my big rig learning things free of charge.
Wow
This video made me to finally understand Inflammation, Great Job!!
Very nice 👌 keep it up 👌👌👌
True💯
One correction, with vasodilation you get increased blood flow not decreased blood flow due to the fact that you have increased radius and thus decreased resistance
I thought that the increase in diameter of the blood vessels is what makes the blood flow slower since more volume = less pressure. The increased blood flow was a result of the concentration gradient from the chemokines. In your case, I think you're equating blood velocity and blood flow. At least that's what I thought. God I hope I'm right cause I got a test tomorrow. Everyone dog pile and make fun of me if I'm wrong though
@@qt3.147 no, you look up possieule equation. With less resistance you get more blood flow essentially. I can't comment on the pressure gradient which produces velocity o the fluid because I don't know that stuff that well
blood flow is different from velocity of blood tho
@@qt3.147 increase in diameter together with exudation of fluid in the microvasculature is what cause slow blood flow, concentration of red blood cell and increased viscosity of the blood, a condition called stasis.
Could you please list your resources for this information!? Thank you.
Hi, thanks for this. I have a concern: is extravasation the same as diapedesis?
Nice
Are you able to cover what happens to the liver's bile production when the gallbladder is surgically removed?
the bile gets directly delivered to the duodenum
I think some mechanisms were active in fatty infiltration after a bad, basically untreated neck injury - no information given from various medical professionals. Mystery infiltration mass-like area on my neck since...& it's all basically killing me...
I was active too... had lots of goals.
Wish more cared about their actual work!
bone remodeling and calcium bone intake
Hi, my wife had an anterior/posterior lumbar fusion in L4/L5 on Jan 24th. About 11 weeks ago. She has no pain, is able to walk miles and work hours, however her right foot still turns pink and gets hot for her. Sometimes there may be just a little swelling at night. Is this heat common? Thank you.
Can we get the photos you used?
Describe the pathogenesis of atheroma (process of atherosclerotic plaque) formation.
Can you talk about the oedema as a whole topic for me please
hello may I ask if the reaction is the same when you have a bruise (wound that didnt open your skin)
Yes, it can happen due to pathogens via PAMPS or NECROSIS (non- programmed death of cells) via DAMPS. Both activate the same pathway via TLR and DLR and the inflammosome. That activates the cytokine expression and IL-1B, respectively.
In change of local blood vessels
In first point you said there is a slower blood flow but there is local increase in blood flow, which manifests as redness and warmness.
This happened in the extravasation video too. I am so confused lol. smaller radius = slow flow? based on Pousille equation?
So an inflammation is in particular helpful and a cleaning mechanism as long as it functions normally right?
Yes
Sir made the video on hypersensitivity
which of the following process is in charge of directing inflammatory cells exactly into the site of injury?
-chemotaxis
-diapedesis
-vasodilation
-adhesion
can you please answer this
HI THERE!! I NEED HELP! I had a biology test some days ago and there was a question whether macrophages produced histamine or cytokines to induce chemotaxis. I chose cytokines bc clearly the cells who mainly produce histamine are basophils and mast cells, but my teacher marked it as incorrect. So can someone explain to me???
@msp banane It turns out there was no correct answer for that question so the teacher just gave us all the points. But thanks anyway! x
@@casiniaciobanu4929 you are very welcome
way better than inflammatory response video of khan academy @khanacademy
00:24 The increased in vascular diameter results in FASTER* blood flow
I caught that mistake too.
No! The blood flow slows...its a phenomenon called "stasis"... He knows what he saying...lool it up
You mentioned local blood vessels when there is a local injury or infection. Are blood vessels affected the same way all over the body in systemic inflammation, such as in some auto-immune conditions?
To the creator of this video,
I ask for permission whether I can use this video and translate it into Indonesian for learning and research purposes?
Thank you and please reply
Hi! You are welcome to add subtitles to this video (would be much appreciated!), but please do not reupload it to a different channel/website. Thanks!
Can tumor site become red and hot from necrosis?
How mnay people understood all this... teaching isnt easy as it appers, its not for everyone
SVP le logiciel avec le quelle vous travailler
comploment system
This doesn't sound like Andrew from SketchyMedical?
Is antibody secreted during inflammation
I’m an engineering student, but watching medical videos during my free time somehow relaxes me. I don’t plan on pursuing medicine as a career, but the workings of the human body is so complex and intriguing. It’s engineering at it’s best! Even more astounding that it’s on a biological level.
Edit: Does anyone know why massaging or touching the site of injury soothes the pain? Is there a biological reasoning for that or no?
pamps and pprs
Actually, vasodilation result in increasing the blood flow.
Susan's Platform yeah, but the blood moves slower
Vasodilation increases blood flow actually
comploment cascade
Added to the list of future topics!
granulocyte family
chemotaxis
In what step can the inflammation stop
kinin cascade
med uff
I’m here from that tik tok. This absolutely sounds like Ben Shapiro at 1.5 speed lol
intro to cytokines
How to eliminate shredded virus and dead particles from body
U would have to power walk and drink ph 9 or 10
Vasodilation increases blood flow, why would it slow it?
Arteriole will dilate which will result to slower blood flow
@@jeno6466 vasodilation’s purpose is to increase blood flow. It might decrease blood pressure, but it does not slow down blood flow.
@@143Al ohh okay sorry. I think I was thinking of vasoconstriction
@@jeno6466 No problem, thanks for trying to help :)
PEA palmitoylethanolamide
So, your body uses pain as a way to alert you to a problem, and stop you from moving the affected body part. My question is...who are you? Who is this consciousness that your body has to relate news to and use pain to communicate with? Who are you? It's just interesting that your body understands that their is a pilot.
That’s God who designed us is this way. This isn’t a random accident like many people believe
phagocytosis
Okay Ben Shapiro