The blood coagulation which you are referring to has several stages and types.
The main cells involved directly are thrombocytes, while endothelial cells etc may also play a role.
There are also soluble factors of the blood involved. (see coagulation cascase)
See
http://en.wikipedia.org/wiki/Coagulation
No. Blood clots are part of a normal period.
platelets
Platelets I think. platelets
Yes, blood clots can pass in menstrual flow. Menstrual blood doesn't clot like normal blood so you won't pass many clots, a lot of what you might see as clots is actually uterine lining that has been shed or cervical mucus that has mixed with blood. Actual blood clots are actually very uncommon.
blood clots doing my period
Periods sometimes have clots because the blood flow during menstruation can be heavy and the blood may clot as it leaves the body. This is a normal part of the menstrual cycle.
They do not form in a blood donation because blood clots are out of our anotomy
Watery blood with blood clots can be a sign of miscarriage. You can also have an unusual menstrual cycle. If you have watery blood with blood clots you need to go to a doctor.
The test is done on a person's serum (the yellow liquid part of blood that separates from the cells after the blood clots ).
If a mosquito bites you on a scab you will not get blood clots. This bite may cause major irritation but it will not give you blood clots.
The living part of blood is the white blood cells (leukocytes) and platelets. These cells are responsible for fighting infections and forming blood clots to prevent excessive bleeding.
Blood clots are caused by certain surgical procedures and diseases.