Cardiovascular Disease and Blood Clotting | A-level Biology | OCR, AQA, Edexcel
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5 سال پیش
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Cardiovascular Disease and Blood Clotting
Cardiovascular Disease and Blood Clotting in a Snap! Unlock the full A-level Biology course at http://bit.ly/2Z6P2fU created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University.
SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* Oxbridge tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks.
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The key points covered of this video include:
1. The Need for Clotting
2. Blood Platelets
3. The Clotting Cascade
The Need for Clotting
When a blood vessel gets damaged there is a chance that internal or external bleeding can occur. Endothelial cells in the vessel wall divide too slowly to stop the bleeding effectively. To overcome this issue the blood contains cell fragments called platelets that cause the blood to clot around a damaged vessel.
Blood Platelets
Damage to a blood vessel exposes the lumen of the vessel to collagen in its wall. When platelets come into contact with collagen they change from discs to spheres with long thin projections. This change enables blood platelets to stick to the collagen, each other and other blood cells in the vessel. This change also causes platelets to release chemicals that help prevent bleeding.
The Clotting Cascade
Blood platelets in a damaged vessel release a chemical called thromboplastin which triggers the clotting cascade. The clotting cascade is a series of enzyme controlled reactions in the blood that lead to the formation of a blood clot. Thromboplastin triggers an enzyme to catalyse the conversion of protein prothrombin into an enzyme called thrombin. The enzyme thrombin catalyses the conversion of soluble fibrinogen into insoluble fibrin forming a mesh. The fibrin mesh traps more platelets and red blood cells forming a blood clot.
Summary
If a blood vessel gets damaged then a blood clot will form to prevent excessive bleeding
Blood platelets are largely responsible for the formation of blood clots
a. They change shape to stick to each other and other cells
b. They help initiate the clotting cascade
The clotting cascade is a series of enzyme controlled reactions that form a fibrin mesh at the site of damage in a blood vessel- this mesh forms a blood clot
SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* Oxbridge tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks.
Sign up today and together, let’s make A-level Biology a walk in the park!
The key points covered of this video include:
1. The Need for Clotting
2. Blood Platelets
3. The Clotting Cascade
The Need for Clotting
When a blood vessel gets damaged there is a chance that internal or external bleeding can occur. Endothelial cells in the vessel wall divide too slowly to stop the bleeding effectively. To overcome this issue the blood contains cell fragments called platelets that cause the blood to clot around a damaged vessel.
Blood Platelets
Damage to a blood vessel exposes the lumen of the vessel to collagen in its wall. When platelets come into contact with collagen they change from discs to spheres with long thin projections. This change enables blood platelets to stick to the collagen, each other and other blood cells in the vessel. This change also causes platelets to release chemicals that help prevent bleeding.
The Clotting Cascade
Blood platelets in a damaged vessel release a chemical called thromboplastin which triggers the clotting cascade. The clotting cascade is a series of enzyme controlled reactions in the blood that lead to the formation of a blood clot. Thromboplastin triggers an enzyme to catalyse the conversion of protein prothrombin into an enzyme called thrombin. The enzyme thrombin catalyses the conversion of soluble fibrinogen into insoluble fibrin forming a mesh. The fibrin mesh traps more platelets and red blood cells forming a blood clot.
Summary
If a blood vessel gets damaged then a blood clot will form to prevent excessive bleeding
Blood platelets are largely responsible for the formation of blood clots
a. They change shape to stick to each other and other cells
b. They help initiate the clotting cascade
The clotting cascade is a series of enzyme controlled reactions that form a fibrin mesh at the site of damage in a blood vessel- this mesh forms a blood clot
5 سال پیش
در تاریخ 1398/02/19 منتشر شده
است.
47,764
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