blood clotting

Question 1

what is blood clotting? what is it also named?

Answer 1

haemostasis and coagulation
- a clot is a plugof platelets, WBC, RBC and plasma trapped in fibrin ,

Question 2

when does it occur?

Answer 2

when there is injury/ damage to blood vessels

Question 3

why does it occur?

Answer 3

to prevent further blood loss/ minimise blood lose and to prevent entry of invading micro-organsims

Question 4

what are the stages in blood clotting?

Answer 4

vasoconstriction
platelets
clotting factors
fibrin
other cells
clot retraction
scab formation

Question 5

what happens in the first stage of blood clotting?

Answer 5

muscles in the walls of the small arteries that have been injured constrict to reduce blood loss

Question 6

what happens in the second stage of blood clotting?

Answer 6

platelets sitck to rough surfaces of damaged vessels and form a platelet plug
- release substances called vasoconstrictors that enhance vasoconstriction

Question 7

what happens in the third stage of blood clotting?

Answer 7

(clotting factors)
chemical substances that strengthen and reinforce the clot
they result in the formation of fibrin( insoluble protien

Question 8

what happens in the 4th stage of blood clotting?

Answer 8

(fibrin)
protein that is in the form of threads, form a mesh to form the clot or thrombus

Question 9

what happens in the 5th stage of blood clotting?

Answer 9

other cells
RBC, WBC, PLATELETES and plamsa get caught in the mesh and reinforce the clot

Question 10

what happens in the 6th stage of blood clotting?

Answer 10

clot retraction
- fibrin contracts and pulls the edges of the blood vessels together
- serum is squeezed out.

Question 11

what happens in the 7th stage of blood clotting?

Answer 11

scab formation
- clot dries, scab is formed over wound preventing infection