Biomedical Sciences Flashcards
Which is more abundant, erythrocytes or lymphocytes ?
RBC much more abundant
Of all the WBC, which are the two most common cells ?
Neutrophils and lymphocytes (both 40-60% each)
Which is the least common form of WBC and what is its function?
Basophils- attracts other WBC
What would a defeciency in megakaryocytes lead too?
A lack of platelets, essential for blood clotting
What can be used to assess blood glucose levels over the last 120 days ?
RBC are useful to assess blood glucose levels, good for diabetes diagnostics
What are first and last progenitors cells in Erythropoesis ?
First cell - megakaryocytes
Last cell - reticulocytes - gives indication of RBC turnover
What are NK cells best at killing ?
Intracellular infections (viruses)
A WBC presents 3 distinct lobes and appears slightly pink, what is likely to be ?
A Neutrophil, one of the most common WBC
How can you distinguish a monocyte from the rest of the WBC ?
They are much bigger and have finger like extensions
What are the 4 stages of wound healing?
1- haemostasis (sec / hours)
2- inflammatory stage (hours / days)
3- proliferatory stage (days / weeks)
4- remodelling stage (weeks / months)
What are the 4 stages of haemostasis?
1- vasoconstriction
2- platelet plug (thanks to the Von Willebrand factor)
3- blood clot (with fibrin)
4- tissue repair, removal of clot (plasmin)
Where are the blood clotting factor mainly made ?
Liver - important for clinical
Which phagocyte is essential in the cleaning up of the wound ?
Macrophage- eats up all the debris
Neutrophils also important for eating any bacteria
Why does the skin sometimes feel tight when it scars up?
Fibroblast synthesised the new skin during proliferation
Sometimes, then can become myofibroblast to pull skin together and increase healing
What happens to the collagen fibres during remodelling?
Collagen 3 turned back into collagen 1
Only 80% as strong
Name two physiological pathways where commensal bacteria are important
AA absorption and Vit K pathway
What makes a bacteria gram positive ?
It’s peptidoglycan layer on its cells membrane
What are the tow pumps for the lymphatic system to drain fluid from the capillaries ?
Skeletal muscle pump - milks the lymph
Respiratory pump - difference of pressure
What colour is the lymph
Normally clear but can become milky if a lot of fat in it
What are the two main lymph ducts, what do they drain and where do they end / drain into?
Thoracic duct - 3/4 of body - internal jugular vein
Right Lymphatic duct - 1/4 top right of body - subclavian vein
How do the cells of the innate recognise foreign cells?
Cells of the innate have
- PRP (Pattern recognition protein)
- TLR (Toll Like Receptors)
Foreign cells have
- PAMPs
Give a brief overview on each complement protein fonction
C3a, C5a - Mast cell and neutrophil activation
C3b - Opsonisation
C5b - apoptosis, cell lysis
What is the difference between MHCI and MHCII and how are the6 involved’ I’m in the bodies immune response?
MHCI are on every cell. When they get infected they express part of the viral DNA / protein in their cytoplasm using their MHCI molecules
MHCII are only APC cells. Once they have migrated to the lymph node, they present part of the phagocyted cells
What is the difference between cell mediated and humeral mediated response ?
Cell mediated - cytotoxic T cells (attracted by IFN-y and IL-2 released by infected cells) - activated by Thelper 1 cells
Humeral Mediated - plasma cells (B-cells p) - activated by Thelper 2 cells
What are the different types of Antibodies and where / when can we find them ?
IgM- first antibody to be released, jack of all trades, not very powerful
IgG - much more potent, more powerful
IgA- in secretary fluids - breast feed, eyes, mucus
IgE- for Parasitic Infections
What temperature is considered a fever ?
37.9C - 41C
What is antigenic drift?
Some animals can host multiple viruses at the same time - using reassortment they mix antigens between them
What are the 3 types of cell that are phagocytes ?
Neutrophils, macrophages and dendritic cells
What is interferon α and how does it work ?
IFN α is realeased by virally infected cells and attracts dendritic cells and NK cells
What are the 3 main area infected by e.Coli , c. Difficile and MRSA? (Common hospital infections)
E. Coli - UTI
C. Difficile - GI tract
MRSA- skin infection
What is anti-microbial stewardship?
Avoiding using general antibiotics, being specific with it
