L5 - Platelets Flashcards
what kind of cells come from common lymphoid progenitor?
1) NK
2) T cell
3) B cell
4) DC
what kind of cells come from common myeloid progenitor?
1) monocytes
2) neutrophil
3) platelets
what do platelets come from?
stem cell -> common myeloid progenitor -> megakaryocyte -> platelet
platelet structure (8)
1) small
2) no nucleus
3) cell membrane
4) 7 mitochondria
5) open canalicular system (continuous cell membrane)
6) dense tubular system for Ca2+ store
7) granules
8) has cytoskeleton
types of platelet granules
1) alpha (most abundant)
2) dense
3) lysosomes
function of actin skeleton in platelet (2)
1) maintain structure
2) reg shape change of activated platelet
what is the platelet cytoskeleton regulated by?
actin binding proteins
what is homeostasis characterized by in terms of action of a protein?
conversion of fibrinogen to fibrin (form blood clot)
chronic inflammation
long term inflammation -> tissue damage
why are platelets SUPER important (2)
1) blood clotting
2) inflammation response (linked to a lot of other diseases)
how to isolate platelet (3)
1) centrifuge blood to get plasma
2) centrifuge to isolate platelets
3) wash and resuspend
how are platelets activated?
have various ligands that bind to platelet receptors
platelet ligands (5)
1) thrombin
2) collagen
3) ADP
4) fibrinogen
5) LPS
what happens to platelets when they are activated?
they stick together
how are granule contents released?
1) fusion of granules with PM or open canalicular system
2) regulated by SNAREs
