HAEMOTOLOGY Flashcards
What are the 3 major components of the immune systems
- receptors and defence molecules
- immune cells
- specialised organs and tissues
define the two immune systems
- innate
inborn defence mechanisms that are found in all classes of animals - Adaptive
acquired immune defences that are unique to vertebrates and generated (memory)
what are leukocytes
white blood cells (specialised immune cells)
What are the two subdivisions of identification based on appearance and what they include
- Agranular (mononuclear cells)
- T cell, B cell and NK cells are LYMPHOCYTES
- Monocytes - Granular
- Basophil, Eosinophil and Neutrophil
What are the two subdivisions of identification based on immune systems and what they include
Innate cells:
- basophil, eosinophil, neutrophil
- monocyte and NK cells
Adaptive cells:
- T cells
- B cells
compare and contrast innate and adaptive cells
innate:
- many types of recognition receptors on each cell
- each receptor coded for by a single gene
- cells are present from birth
- recognise mainly microbial cells (not self)
Adaptive:
- one type recognition each cell (unique)
- receptors assembled from multiple gene fragments (shugfling)
- formed after birth
- recognise all antigens (non and self)
What are haematopoietic stem cells
specialise into leukocytes - found in bone marrow
what types of cells do haematopoietic stem cells give rise to?
- Lymphoid progenitor cells
- myeloid progenitor cells
what cells do Lymphoid progenitor cells give rise to
T cells, B cells and NK cells
(lymphocytes)
what cells do myeloid progenitor cells give rise to
myeloid cells:
- monocytes
- basophils
- eosinophil
- neutrophil
final destination of granulocytes
move from blood into tissues (includes Neutrophil, eosinophil, basophils)
- also includes mast cells but unknown where they originate from
final destination of monocytes and NK cells
monocytes start in blood, move to tissues and mature to become macrophages or denritic cells
NK cells start in blood, move to tissues and form granules
functions of the innate immune cells
- phagocytosis -monocytes, basophils, neutrophils, Dendritic cells
- granule release - nuetrophils, basophils, eosinophils, mast cells, NK cells
- target cell killing - NK cells
- Triggering inflammation - macrophages
- Antigen presentation - macrophages + dendritic cells
monocytes vs macrophages
both white blood cells
- monocytes are blood defence
- macrophages are tissue defence
monocyte becomes macrophage in tissues
- macrophages engulf pathogens via phagocytosis and pinocystosis and destroy them with toxic vesicles
what are neutrophils and what’s special about them
- a white blood cell -> a granulocyte, a phagocyte
- highly efficient at engulfing and killing pathogens but only short lived (72hrs)
- make up majority of white blood cells
how do neutrophils work
- recruted to infected tissues
- hunt down microbes as they are drawn to molecules that bacteria release
- ingest cells and release enzymes to break down
what is degranulation and what is it used for
- granulocytes release their granules
- used to attack cells or create DNA net to trap bacteria (neutrophils)
where do T and B cells mature?
in specialised immune organs
t cells mature in thymus
b cells in bone marrow
What are the steps of T and B cell maturation?
- rearrange gene segments (random combinations) to make unique antigen receptor
- test unique antigen receptors (do they work?
- remove any cells with self-reactive receptors (reaction to bodies cells)
what is a mature t or b cell called
naive lymphocytes
what s the final destination of naive lymphocytes (t cells and B cells)
both move between blood and lymph nodes/spleen, never stay one spot forever
what are the primary vs secondary immune organs?
Primary:
- Thymus
- Bone Marrow
Secondary:
- Spleen
- peyer’s patch in intestine
- appendix
- lymph nodes
what type of defence do t cells and b cells provide
t cells = cell-mediated immunity
b cells = antibody-mediated immunity
where are naive lymphocytes (t + b) activated?
secondary lymphoid regions (spleen and lymph nodes)
functions of lymphatic system
- maintnance of blood volume
- filtration of foreign materials
- development/maturation of lymphocytes
- initiation of specific immune responses
components of lymphatic system
- lymph
- lymphatic vessels
- lymphoid organs
- lymphoid cells
what do lymphatic vessles do
- transport interstitial fluid (lymph) from the tissues (escaped from blood) back into the blood
- drain 3-4L a day
what is lymph composed of
- interstitial fluid
- solutes
- lipids
- foreign materials
- immune cells
why does lymph build up?
blood transported under pressure, through vessels. Vessels are porous to allow O2 and other things to pass through, lymph leaks out too.
how do lymphatic vessels drain lymph from tissues?
- lymphatic capillaries are single cells overlapping. Means that lymph can squeeze between. Body movement and valves then propel lymph along vessels.
where does lymph go once drained?
- lymphatic vessels drain into lymph nodes, which filter the lymph via lymphoid cells
- then moves into vessels again
- vessels collect into lymphatic trunks
- trunks collect into 2 main ducts which return lymph into the blood systems (link)
what are the lymphatic trunks
label
- right jugular trunk (neck(
- right subclavian trunk
- right bronchomediastinal trunk (near clavicle)
- left bronchomediastinal trunk
- right lumbar trunk
- left lumbar trunk
what are the two lymphatic ducts
- right lymphatic duct ( right head, shoulder and arm area)
- thoracic duct -
where do lymphatic and circulatory syetm connect
diagram
- thoracic duct - left subclavian vein and left internal jugular vein
- right lymphatic duct - right subclavian vein and right internal jugular vein
what do lower GI tract lymphatic vessels do?
- allow for transport of lipids back to bloodstream for uptake of fats from food
what is chyle
lymph containing lipids
what is chylothorax
- when thoracic duct is damaged so chyle builds up
Explain the adaptive immune reaction
- foreign substance (antigen) enters body and triggers response first in secondary lymphoid organs
- lymph nodes trap antigens coming from tissues (in lymph)
- lymphocytes enter lymph nodes from the BLOOD
- lymph nodes bring antigen and lymphocytes together and react
- B and T cells interact with antigen for first time, proliferation (lag of 3-6 days for production), cloning. some cells survive and are memory cells
- second interaction, proliferation of memory t and b cells (many more available). Lag time only hours.
when do primary and secondary responses peak
primary =10-12 days
secondary = 7 days
compare and contrast circulatory system and lymphatic system
BS:
- transports blood and lymph
- major vessels include Artery, veins and capillaries
- filtration occurs in kidney and liver
- intersects at right and left subclavian veins and internal jugular vein
Lymphatic:
- transports lymph
- major vessels = lymphatic capillaries, vessels, trunks, right lymphatic duct and thoracic duct
- intersect in ducts
