Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

17. The Blood

Introduction To Blood

Anatomy & Physiology

17. The Blood

Introduction To Blood

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Multiple Choice

Which of the following is true regarding the extrinsic pathway of blood clotting?

It is slower than the intrinsic pathway.

It requires the activation of factor XII.

It is initiated by tissue factor released from damaged tissues.

It does not involve calcium ions.

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Verified step by step guidance

Understand the context: Blood clotting involves a series of complex processes that prevent excessive bleeding when a blood vessel is injured. There are two main pathways: intrinsic and extrinsic.

Identify the extrinsic pathway: The extrinsic pathway is initiated by external trauma that causes blood to escape from the vascular system. It is triggered by tissue factor (TF), also known as factor III, which is released by damaged tissues.

Compare the speed: The extrinsic pathway is generally faster than the intrinsic pathway because it involves fewer steps and is directly activated by tissue factor.

Factor XII involvement: Factor XII is part of the intrinsic pathway, not the extrinsic pathway. The extrinsic pathway does not require the activation of factor XII.

Role of calcium ions: Calcium ions are essential for both intrinsic and extrinsic pathways. They act as cofactors in various steps of the clotting process, including the activation of certain clotting factors.