Immunology Map IV - Innate Immune response I

0:00 Adan biology and Medicine videos please make sure to subscribe join the foran group for the latest videos please visit Facebook atram please like and here you can also ask questions answer questions and post some interesting things including artworks it' be greatly appreciated or send them to me and you can also change the quality settings to the highest one for better graphics now in the last video we learned how the lymphoid precursor cell which we uh which would become a te- cell so we just call it a t- cell precursor enters the thymus um and this t- cell precursor expresses no cd8 or CD4 co-receptor uh but through t- cell development in the thymus it will become a naive t- cell expressing both CD4 and cd8 and then it will become either an KN

0:46 T Cell only expressing cd8 or an KN cell only expressing CD4 cor receptor and then from the thymus these KN T cells the CD4 and cd8 KN T cells will go and travel through the bloodstream into the peripheral lymphoid organs such as the lymph node and they are situated in the paracortex and in the lymph node we also have the germinal center where the B cell has has migrated to and then we have the afren vessels which bring certain cells in into the lymph nodes as well and we have the eant uh vessels which brings activated um lucco sites out of the lymph node

1:32 typically now in this video we are part four I think we are going to learn about the innate immune system so what happens during a um an invasion of a pathogen in a tissue so what happens for example if a nail or some object penetrates the skin or tissue somewhere and it brings in pathogens our tissues will become possibly inflamed during a pathogen Invasion so what would Ty Ally happen is that chemical signals will of course recruit more Luc coytes to basically apprehend the invading pathogen stopping it and then we also have the complement proteins which play a critical role in the innate immunity making making it easier making the it easier for the

2:19 lucco sites to destroy the pathogens basically so we have more more lucco sites going into the infiltrated area typically neutrophils because neutrophils are very fast acting so again in case of inflammation due to the invasion of the pathogen more lucites are recruited into the dam damaged or infiltrated area what's important to know is that if a pathogen has infiltrated the body it can cause an infection of course and obviously an inflammation and what the innate immunity's role is is to basically uh stop the pathogen in its track but if it's a first exposure to the pathogen it's a bit difficult for

3:05 the innate immunity to destroy it and so the innate immunity's role in this case is to Halt it uh and wait for the pathogen to be recognized by the Adaptive immune cells the BNT cells but how does this happen well the dendritic cells have play a critical role in that it will become activated once it uh once it basically fago sizes the antigen the pathogen and then it brings the antigen of the pathogen travels to the lymph nodes with the antigen of the pathogen and presents it to the tnb cells so the T and B cells can become activated and so now the Adaptive immune response uh can also now recognize a pathogen and so it try to destroy it together with the anate immune cells so let's go back to the big Immunology map

3:51 now and let's uh look at it in a bit more detail what happens when the tissue gets infected and becomes infiltrated by pathogen so in the last video we learned how the naive T cells the CD4 and CD naive T cells enter the par cortex of the lymph node through the high endothelial venal and how the immature B cells as well enter the cortex of the lyph node through this High endothelial venal and remember that these lymphocytes they are not active yet because there is no pathogen Invasion yet so now let's go back to the tissue uh this healthy tissue and see what would happen if for example a nail has penetrated this this particular tissue it can be beneath our skin for example and this nail that penetrates tissue can possibly bring in some form of pathogen

4:37 and this green here I represent as pathogen and it can be for example a bacteria this pathogen would be recognized by the innate immune cells because it expresses what's called PMs and I've made a video on pmps if you want to watch it I'll provide the link right now now these these um these immune cells inate immune cells will recognize the PPS of this pathogen and for example the mass cell would recognize this and will start um secreting histamine as an inflammatory response or as an pathogen invading response histamine what will it cause it will cause vasod dilation and increase the vascular permeability of the blood vessels and at the H similarly uh the

5:24 tissue maccrage which also recognizes these pmps will start secreting cyto which would attract more lucco sites or telling the more lucites to come into this infiltrated area and so histamine together with the cyto secreted by many of the innate immune cells will attract and enable the circulating lucco sites to enter the infiltrated area typically a neutr which are the fast acting cells and so they travel they circulate through the body and and and enter the infil ated area the quickest and begins ftiz um these these pathogens so the two important cells uh which will initiate the inate immune

6:10 response are essentially the macrofagos as well as the neutrophil and the maccrage and nutrifil will engulf the pathogens in a process known as phagocytosis now the complement proteins here will also enter this tissue and the complement proteins um help destroy the pathogen and also uh stimulate phagocytosis so it stimulates destruction and phagocytosis of the pathogen and how does it do this well I made a video on the coment protein as well you can click on the link now and watch it now what is phagocytosis the nutrifil and the maccrage uh does this phagocytosis let's have a closer look at the tissue maccrage ftiz a pathogen because a

6:58 tissue maccrage plays a critical role in that once it ftiz a pathogen it will secrete cyto kindes to recruit more immune cells so what happens