Module 4 Flashcards
3 Main Cell Types in Blood:
-red blood cells (erythrocytes)
-no nucleus, have haemoglobin and transport O2 and CO2
-white blood cells (leukocytes)
-nucleated multiple types, immune cells, about double the size of RBCs
-platelets (thrombocytes)
-no nucleus, they’re more like cell fragments, allow clotting
Hematocrit:
=amount of red blood cells compared to rest of blood
-centrifuge blood, about 40-54%
-20% hematocrit (red blood cell conc.) = anaemia, iron deficiency, issues with bone marrow, vitamin deficiency
-increased hematocrit (red blood cell conc. of 55%) = dehydration, extended delayed cord clamping in newborns, polycythemia (bone marrow makes too many rbc) high altitudes, smokers - hypoxia
White Blood Cell Values:
-low wbc could be due to weakened immune system, immunocompromised people, HIV, cancer treatments such as chemo (impact dividing cells)
-high values can be due to allergic reaction, infection/sick, leukaemia (blood cancer of massive overproduction of immune cells)
Haemoglobin:
-is a globin protein consisting of 4 polypeptide (protein) chains
-has one heme pigment attached to each polypeptide chain
-each heme contains an iron ion that can combine reversibly with one oxygen molecule
Recycling of RBCs:
-120 day lifespan - rbcs wear out from bending to fit through capillaries
-no repair is possible due to lack of organelles
-rbcs are broken down into components and reculed: macrophages break haemoglobin and heme and globin
-macrophage in liver/spleen break apart haemoglobin
-globin can be broken down to amino acids to be used for other things
-heme can be brien into iron to be used in bone marrow for haemoglobin synthesis and a non-ron portion that is converted to biliverdin and then converted to bilirubin (yellow)
-no
-bilirubin travels via blood to liver and is conjugated with glucuronic acid and can be recycled into bile
-bilirubin goes to small then large intestine where it is broken to urobilinogen
-urobilinogen is eliminated in faeces as brown pigments stercobilin
-some urobilinogen goes back into the blood and is converted to urobilin (yellow that exits the body in urine
2 Main Arms of Immune Systems:
-innate immune system (born with, no training needed, not specific)
-adaptive immune system (trained to have, adapt to what we see)
Staphylococcus Infection Overcoming Innate Immunity:
-staphylococcus is a bacteria
-skin → sloughs off, is acidic, tightly packed keratinized layer to get through
-if it was a mucosal surface such as nose and lungs → cilia can trap microbes and propel it, tears to wash eyes, urine to wash urinary tract
-chemical: sebum from skin inhibits bacterial growth, lysozyme in perspiration can breakdown bacterial walls, dermicin in sweat glands of skin can bind bacterial membrane and makes holes
-vagina and stomach are very acidic, mucous and IgA antibodies
-2nd line of defence: inflammation, macrophages and neutrophils (phagocytes in tissues), dendritic cells/langerhan cells in skin, NK cells are all ready to act
Acute Inflammation: (below is all innate response - see something is wrong but don’t know what)
-damaged cells signal adjacent cells that something is wrong (interferons) (cytokine)
-pattern recognition receptors (PRRs) on a normal cells activate inflammation
-a tissue resident macrophage becomes activated and may phagocyte pathogen and release cytokines/chemokines
-cytokines produced by macrophage cause dialton of local small blood vessels
-leukocytes move to periphery of blood vessel as a result of increased expression of adhesion molecules
-leukocytes extravasation at the site of infection
-blood clotting occurs in microvessels
What Cells can Phagocytose Pathogens:
-neutrophils, 1st phagocyte to move from blood to tissue in inflation
-monocytes, located in blood, migrate to inflamed tissues in response to chemokines, biome macrophage that can phagocytose and kill pathogens
-dendritic cells (DC), tissue resident and move into the tissue
How do These cells (innate) Recognize a Pathogen:
-pattern recognition receptors (PRRs) that can see special PAMPs (pathogen associated molecular patterns)
Why are Dendritic Cells (DCs) Special:
-a DC ends up linking the innate immune response the the adaptive immune response so adaptive knows when to come in because innate isn’t enough
-they use PRR to recognize and phagocytose pathogens
-next they [process the pathogen and present parts of it on their surface (antigen prescient cell -APC)
-they then travel to the lymph node (LN) where they can present the antigen from the pathogen to t cells
-this will activate an adaptive immune response to the pathogen
The NK natural killer Cell:
-discovered due to their ability to spontaneously kill tumour and virally infected cells
-NK cells are actually lymphoid lineage
-found in blood and tissues
-kill via perforin (make a hole in the cell) and granzyme (enters hole and causes apoptosis) release cytokine
Adaptive Immune Response Order:
-antigen recognition, activation of lymphocytes, decline of effector cells
Antigens:
-anything that can bind to an antibody
-may be toxic/foreign or nin-self (pathogen), also can be self molecules expressed at wrong place/time
-may be proteins, polysaccharides or lipids
-an epitome is a small defend restricted on antigen that actually binds to receptor
Antigen Presenting Cells:
-dendritic cells, macrophages and b lymphocytes
-these cells process and display antigens as peptides in the MHC molecules and can activate t cells
-DC are the best at being an APC (macrophages are the best at phagocytes)
