1. what happens when platelets come into contact with damaged vessel wall?
- they release a chemical which activates more platelets causing a build up of platelets and so blood cannot flow though properly.
- they change from discs to spheres with long projections and their cell surfaces change making them stick to the exposed collagen and to each other forming a platelet plug. they also release substances to activate more platelets.
- they release a sticky substance and stick to the formed plaque, forming a platelet plug. they also release substances to activate more platelets
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Other questions in this quiz
2. what does the fluid in blood, plasma, contain?
- mainly water, and dissolved substances eg food, oxygen and co2
- water and oxygen or co2
- food and other molecules, proteins and water
- water and dissolved molecules
3. what does it mean if something is a polar molecule
- it has an unevenly distributed electrical charge
- it has an evenly distributed electrical charge
- it consists of a giant lattice of oppositely charged ions
4. how does the blood flow in a closed circulatory system?
- it circulates in large open spaces
- blood is enclosed in tubes and is forced along fairly narrow channels
- heart pumps blood into cavities surrounding organs
5. which valves are closed during diastole?
- semilunar valves
- atrioventricular valves
- bicuspid valves
- tricuspid valves