6 - Innate and adaptive immunity Flashcards
Why do lymph nodes swell
The virus antigen in the tissue fluid drains to the nearest lymph node. The lymphocytes recognise the shape and proliferate and generate an immune response. The proliferation causes the node to swell
Normal size of lymph nodes
broad bean
What may a single swollen lymph node be a sign of
May be a cancer of the blood
Describe the shingles virus?
He already had this virus in his system. This virus had previously caused chicken pox. The virus has integrated some of its DNA into our nerve cells. A stress event (scratch) can cause the virus to reactivate and the DNA starts to multiply and create more virus that bud off from the nerve and infect more cells causing an acute local inflammation
latent virus
virus integrates some of its dna into our cells
Do all infections come from the outside?
No. Some are within us and become activated after being latent for some time
Secondary lymphoid organs act as … and …
filters and immune response factories
Does repeated infection improve resistance for innate and adaptive immunity?
Yes for adaptive no for innate
What do BVs and lymphatics do?
Bring antigens IN to secondary lymphoid organs (spleen, nodes..) and take immune effectors out
How is the adaptive immune system activated?
By activation of lymphocytes and is improved by repeated exposure to antigen
How do most pathogens enter the body and what are the consequences of this?
Most pathogens enter the body by epithelial surfaces i.e. at the nasopharynx, gut, lung, GI tract and so there are heafty defenses at these sites
Most pathogens can’t get past the protective biophysical barrier of the skin
Why are burn victims a big concern for infection
Remove the skin biophysical innate defense so very susceptible to infection
All blood cells develop from…
BM stem cells
Haematopoeisis
Tcells
made in BM like other blood cells but develop in the thymus P
Platelets develop from
megakaryocytes
Where is the thymus
Under the sternum
Do b and t cells look the same
Yes but different functions
primary compared to secondary lymphoid organs
1 - made
2 - see shapes/epitopes and respond here
Are exported from 1 to 2
Do innate immune response recognise antigen/shapes or just biochemical and physical
Yes they do - phagocytes and NK cells
What do blood cells develop from
Pluripotent haemopoietic stem cells under the influence of microenvironmental factors such as cell surface molecules, cytokines and hormones
Are platelets cells
No they are cellular components created by megakaryocytes in the marrow
Megakaryocytes stay in BM and pinch off small portions of cytoplasm that contain clotting factors and release them into the bloodstream as platelets
What pathway forms the blood cells
myeloid differentiation pathway
What do RBCs derive from
Reticulocytes - have nuclei but RBCs dont
How many lineages of blood cells are there
4 Myeloid pathway > WBCS megakaryocytes > platelets reticulocytes > rbcs lymphoid > lymphocytes
What cannot function as an antigen for the IS
Virtually nothing can’t function as an antigen as long as it is BIG enough to have antigenic epitopes that can be recognised by the IS i.e. most of a persons molecular structures can act as antigen in someone elses body (transplantation rejection i.e.)
Repertoire of antigenic shapes the IS can recognise
very large
microbes, dust, chemicals, human cells
