BIOL10002 Lecture Notes - Lecture 25: Aspirin, Dermis, Lysozyme
Lecture 25
The Immune System, part 1
Removal of pathogens
1. Innate (First line of defence) – phagocytes etc (first 4 hours)
2. Innate (second line of defence) – macrophages etc (4-19 hours)
3. Adaptive (third line of defence) – T and B cells, takes 4 days (96 hours)
Innate immunity – rapid, non-specific response
Adaptive immunity – can distinguish between self and not-self, slow and long lasting
Blood cells
also need to know complement proteins, antibodies, TH cells and TC cells
Lymphatic system
B cells mature in bone marrow and then circulate in blood and lymph
T cells migrate from bone-marrow to thymus and then circulate in blood and
lymph
Note: lymph and plasma are the same except lymph has no red blood cells.
Lymph is not circulated, but physical movement moves it around the body.
Macrophages phagocytose, secrete defensins which poke holes in pathogens, antigen presenting
cells
Mast cells are found in the connective tissue – secrete histamine
Complement proteins are in innate and adaptive system, they coat bacteria that help phagocytes
recognise and kill the pathogen, leading to the lysis of pathogens
Interferons are cytokines - signalling proteins made and released by host cells in response to the
presence of several pathogens
Neutrophils stimulate inflammation – can phagocytose things but cause a lot of debris
First line of defence
skin, mucus, cilia, chemicals (lysozyme), flora
Second line of defence
mast cells, phagocytes, complement, interferons, inflammation, fever, mast cells
1. signals are sent which attract mast cells which secrete histamine, which makes the arterioles
dilate and release more fluid into the capillaries, and they become leaky.
2. Complement moves out of the plasma into the dermis, and coat the bacteria.
3. Macrophages move into the affected area and bind to and engulf pathogens.
4. Blood plasma moves into the dermis causing swelling, containing the bacteria in a specific area.
5. Platelets release growth factors which stimulates dermis cells to divide to heal the wound.
Aspirin blocks production of prostaglandins (which hypersensitive the cells to pain) produced by
inflammatory cells to get rid of the pain
Stuff that shouldn’t happen
Sepsis is generalised inflammation around the body.
- Life threatening
Oedema
+ more
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Adaptive immunity can distinguish between self and not-self, slow and long lasting. Also need to know complement proteins, antibodies, th cells and tc cells. B cells mature in bone marrow and then circulate in blood and lymph. T cells migrate from bone-marrow to thymus and then circulate in blood and lymph. Note: lymph and plasma are the same except lymph has no red blood cells. Lymph is not circulated, but physical movement moves it around the body. Macrophages phagocytose, secrete defensins which poke holes in pathogens, antigen presenting cells. Mast cells are found in the connective tissue secrete histamine. Complement proteins are in innate and adaptive system, they coat bacteria that help phagocytes recognise and kill the pathogen, leading to the lysis of pathogens. Interferons are cytokines - signalling proteins made and released by host cells in response to the presence of several pathogens. Neutrophils stimulate inflammation can phagocytose things but cause a lot of debris.
