starlets
In a blood smear platelets appear as discshaped cellfragments
average 2 3 pm in diameter and I am thick
contain granules
play a major role in a vascular clotting system
siatelet function
releasing chemicals important to the clotting process
Forming temporary patch in the walls or damaged blood vessels
reducing the size of a break in a vessel wall
siatelet production
takes place in the red bone marrow
normal red bone marrow has megakaryocytes which are enormous cells with largenuclei
they growand mature to shred their cytoplasm in small membrane enclosed packets
these packets are the platelets that enter the bloodstream
thrombopoietin too is a peptide hormone that accelerates platelet formation and stimulates the production
megakarocytes
platelet formation is a negative feedbackloop
tomeostasis blood clotting
the process of homeostasis the stopping of bleeding halts theloss of blood through the walls or
damaged vessels establishes a framework for tissue repair
has three phases the vascularphase the platelet phase and the
Homeostasis coagulation phase
It is a complex cascade in which manythings happen at once
meters
masons
me coagulation phase
conversion of soluble plasma protein to the insoluble rigidpolymer fibrin
endpoint starts 30s ormore after thevessel has beendamaged
normal blood clotting depends on the presence or clottingfactors
the coagulationprocess
Involves the chain reactions of the extrinsic intrinsic and common pathways
the extrinsic pathway
Begins outside the blood stream inthe vessel wall
starts when damaged endothelial cells or peripheral tissue release factor in also called tissue factor
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller camip. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.