Anatomy and Cell Biology 3309 Lecture 10: Cells of the Immune System
22 May 2018
School
Department
Professor
Histology 3309
Cells of the Immune System
Learning Outcomes
- list the components of the lymphatic system
- relate the function of lymphatic vessels to their structure
- describe basic mechanisms of T cell, B cell and NK cell activation
- distinguish bw diffuse lymphatic tissue, primary lymphatic nodules and secondary lymphatic
nodules
What does our immune system do?
- After we are born, our immune system is still developing
o We are still being exposed to diff antigens
- Vaccinations work bc we are priming our immune system
- The immune system is going to target antigens
- Antigen: any substance that can mount a SPECIFIC immune response
How is our immune system organized?
- Humoral immunity is antibodies
- T cells and B cells and natural killer cells are lymphocytes
Overview of the Lymphatic System
- Lymph fluid is an acellular composition of blood
- Not completely acellular bc you have immune cells but you dont have any RBC
- Lymphatic system and lymph fluid is carrying our immune cells, and antigens throughout our
body and we have a bunch of different things in our body so that we can intercept if there is any
pathogen coming in to mount an immune response
- Lymphatic systemi s connected to vascular system
- Lymphatic system is divided into…
o Organs
▪ Aka educators (bc this is where its being educated)
▪ Where some of our naïve cells as they are developing here
▪ They are maturing in this part
▪ They are not exposed to antigens in the thymus, bone marrow, and spleen but
they are developing
o Lymph vessels
▪ Connects diff parts of lymphatic system together
o Cells
▪ Lymphocytes (B cells, T cells and Natural killer cells)
• NK cells are apart of the innate response
▪ Supporting cells
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find more resources at oneclass.com
• Ex:l ymph nodes, spleen, thymus
• These cells are not immune cells (which carry out some sort of
developing antibodies, or attacking a pathogen) but they are really
important in mounting an immune response)
o Lymphatic tissue
▪ Battle ground
▪ Where we are going to develop the immune response
▪ Where mature B and T cells encounter their antigen, have their immune
response (either through humoral or cell-mediate immunity) and be able to
fight off the pathogen
▪ If it does this really effectively (like it has been exposed to it previously or
vaccinated), you are not even going to notice that you are sick – immune system
takes care of it before symptoms show
- Lymph vessels are distributed throughout our body
- They collect fluid from the interstitial fluid that is surrounding our cell and helping our body
mount an immune response
- Lymph nodes are distributed around the body
- Diffuse lymphatic tissue
o Like the battleground
o Where most of our immune responses are being generated
o Bronchus-associated lymphoid tissue (BALT): Lymphoid tissue underlying mucusoa
membrane within respiratory system
o Gut- associated lymphoid tissue (GALT)
o BALT and GALT can be referred to as MALT together
▪ Both of them are associated with the mucosa within some of our tracts within
our body
▪ We must have a good interception of pathogens in these areas
▪ Think about where you get sick: respiratory system or gut
▪ So its really important that diffuse lymphatic tissue is at these barrier/junctions
where pathogens can come in
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find more resources at oneclass.com
Primary VS Secondary lymphoid organs
- Primary lymphoid organs
o Where education happens
o In thymus, bone marrow and GALT
▪ Its in the GALT bc some immune cells develop along our digestive tract
o But thymus and bone marrow is where lymphocytes undergo antigen independent
differentiation and reach maturity – they become immunocompetent
o This means they are able to go out – after their education in the thymus or bone marrow
– and elicit a response in the diffuse lymphatic tissues, lymph nodes and nodules and
spleen
o There is no antigen at this point
o Once this education is done, they can call themselves immunocompetent
o They are called T cells bc this education happens in the thymus
o Education of B cells happen in bone marrow
- Secondary lymphoid organs
o Diffuse lymphatic tissue, spleen, lymph nodes and nodules
o Battle ground
o Where we elicit our immune response
o Ex: if you are sick, you can feel like your lymph nodes are swollen in your neck (this is bc
youre mounting the immune response)
o These cells are activated by the one antigen that activates them
o This allows them to proliferate and have their different effect (depending on the type of
cell)
o Secondary lymphoid organs can become effector and memory cells
▪ Ex: when you get your flu shot, you are making memory cells – this is why if you
encounter the flu virus, your body mounts an immune response and you never
get sick
Question slide
Which of the following statements is FALSE about the bone marrow?
a) Bone marrow is a primary lymphoid organ
b) Bone marrow is the site of T cell education
c) Bone marrow participates in antigen-independent B cell development
d) Bone marrow produces immature B cells
A: B – bone marrow is the site of B cell education
Lymph vessels connect tissues and blood vasculature
- Lymph vessels connect our tissues and our blood vasculature – they are an intermediary
- They connect the interstitial fluid and find a way for it to get back into our circulation
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Learning outcomes list the components of the lymphatic system relate the function of lymphatic vessels to their structure. Describe basic mechanisms of t cell, b cell and nk cell activation. Distinguish bw diffuse lymphatic tissue, primary lymphatic nodules and secondary lymphatic nodules. After we are born, our immune system is still developing: we are still being exposed to diff antigens. Vaccinations work bc we are priming our immune system. The immune system is going to target antigens. Antigen: any substance that can mount a specific immune response. T cells and b cells and natural killer cells are lymphocytes. Lymph fluid is an acellular composition of blood. Not completely acellular bc you have immune cells but you don(cid:495)t have any rbc. If it does this really effectively (like it has been exposed to it previously or vaccinated), you are not even going to notice that you are sick immune system takes care of it before symptoms show.
