Immunology 1 Flashcards
What does the immune system do to parts of a pathogen or antibody when it dies?
- Take body parts of pathogen and display them on immune cells i.e. t/ b cells and macrophages
What are the two immune systems that travel around the body?
(2 marks)
- Lymphatic and Cardiovascular
What immunological components are used as the first line of defence from a pathogen?
(4 marks)
- Anatomical barrier - skin, mucous lining
- Chemical barrier - antibacterial peptides
- ‘Strategic’ outposts - mucousal associated lymphoid tissues (MALTS) - in gut
- ‘Guards’ - epithelial cells, macrophages, dendritic cells - kill on site
What do memory B cells do?
- Retain information on pathgoen - if re-infected can kill pathogen quicker
How does the immune system communicate with eachother?
(3 marks)
- Cytokines - send messages to rest of immune system and recruit cells to site of infection
- Macrophages and dendritic cells - antigen presetnign cells
- T helper cells - communicate with other cells in immune system
Where are the different checkpoints in the immune system?
- Lymph nodes - checks for circulating pathogen in tissues
Why is clonal expansion of T and B cells needed?
To fight infection - these are transported by lymphatic and cardiovascular system to site of infection
What are teh different ways that you can kill a pathogen?
(3 marks)
- Macrophages EAT pathogen repreatedly
- Neutrophils eat pathogen and then die
- Natural killer t cells (cytotoxic T cells) - v. specialised
What do reconnasance dendritic cells do?
(2 marks)
- Look for pathogens, understand and report back on pathogen
- Eat it and display body parts of pathogen on surface of body
What do ammunition B cells do?
- Make specialised antibodies
What do complement system proteins do?
(2 marks)
- Encounter pathogen and stick to its surfaceas recognise common features on pathogen
- Will kill directly or recruit other immune cells to kill that pathogen
Why does the immune system’s defence have to be continually updated?
(3 marks)
- Pathogen can evolve very quickly through rapid doubling and therefore may be able to overcome defences
- And humans can only double very 20-40 years
- BUT B cells and T cells can evolve quicker than us and can tweak DNA to kepp up with pathogen quick evolution
- If pathogen evolves quicker suffer from disease
What is the innate immune system and its function?
(6 marks)
- First line of defence
- Fast response to invasion
- Non-specific molecules for pathogens
- Broad sepcificity
- Response always the same
- Triggers adaptive immune response
What components does the innate immune system contain?
(4 marks)
- Humoral components:
- Blood
- Plasma
- Interstitial fluid
- Cell mediated components
What is the adaptive immune system?
(3 marks)
- Recognises specific epitopes i.e. AA sequence
- Slow response
- Remembers structure - improves activity to kill pathogen (2nd infection) much quicker
What components is the adaptive immune system made up of?
(2 marks)
Humoral components
Cell-mediated components e.g. B and T cells, lymphocytes
What does the lymphatic system do?
(4 marks)
- Moves cells around the body
- Contains checkpoint
- Mucousal associated lymphnode tissue
- Supports cardiovascular system
What are the primary and secondary lymphoid organs?
(2 marks)
Primary - bone marrow and thymus (B and T cells mature here)
Secondary - Spleen, tonsil, adenoid
What other system does the lymphatic system support?
Cardiovascular system - as lymphatic system allows for the transport of tissue fluid
How does tissue fluid pool back into the heart from the lymphatic system?
(3 marks)
- High pressure in the arteries pushes plasma into the arterioles across the tissue bed where capillaries are rleasing palsma into tissue
- Pressure higher in tissue bed then in venules, so plasma pushed into venules
- It pools back into venous blood where there’s low pressure and back into right atrium of the heart
How much interstitial fluid is lost everyday?
Roughly 3L
What is the lymph node and what goes on there?
(3 marks)
- Meeting point for innate immune cells and adaptive immune cells
- Lymphatic cells screen lymph for pathogen to stop pathogen from reaching the blood
- B and T cells are activated in lymph node after coming into contact with cell
What is haemotapoiesis?
(3 marks)
- part of INNATE IMMUNE SYSTEM
- Haemataopoetic stem cells= immune and blood stem cells dervied from one stem cell
- Multipotential haem. stem cell - either become myeloid progenitor cell or form erythrocytes, mast cells or myoblasts
- Myoblasts these differentiate into many white blood cells THEN into macrophages and dendritic cells THEN into granulocytes
What do the common lymphoid progenitors create in the adaptive immune system?
(2 marks)
- Common lymphoid progenitors create: lymphocytes, natural killer t cells and small lymphocytes i.e. T lymph and B lymph - which turns inot a plsam cell
- Granularcytes are a part of adaptive immune system - large blobs of DNA
What is the process of haematopoeisis?
(5 marks)
- Immune system cells start develpoment in yolk sac and then liver then spleen take over
- Then any immune cells made in the bone marrow after birth and developed in long tibia and femur up until 30 yrs old
- Vertebrae and pelvis take over and make them as have red medullary bone marrow
- Long part of bone has red medullary bone marrow and creates imune system cells
- As we age, becomes yellow medullary bone marrow which is adipose tissue and NO LONGER MAKES IMMUNE CELLS
How is a stem cell niche created?
(2 marks)
- Fibronection guides cell once it has been changed out of bone marrow and to to its next destination
- Haematopoetic stem cell creates many cell adhesions with different cells that signal to it and what it should become and links ECM molecules
What do myeloid progenitor cells become?
(3 marks)
- Macrophages/ progenitor cells or granulocytes
- Megakanocyte (makes platelets once in blood)
- Erythroblast and when it reaches blood a erythrocyte
Where and what are multipotential haematopoetic stem cells maintained?
Maintained as stem cell in bone marrow - necessary tomaintain a bank of stem cells
What does an interleukin do?
- Dictates which lineage cells will go into
What do IL-7 and IL-3 do?
(2 marks)
- IL-7: pushes stem cells inot lymphoid progenitor lineage
- IL-3: pushes stem cells inot myeloid lineage
What does teh granulocyte macrophage colony stimulating factor do?
(2 marks)
GMCSF
- Sends myeloid progenitor cells down to myoblast lineage and makes neutrophils
- Sends cells down into monocyte lineage into macrophages and monocytes
