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

1. Introduction to Anatomy & Physiology

Introduction to Organ Systems

Anatomy & Physiology

1. Introduction to Anatomy & Physiology

Introduction to Organ Systems

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Multiple Choice

What distinguishes the three different classes of levers found in the human body?

The relative positions of the fulcrum, effort, and load

The type of muscle tissue involved

The direction of blood flow through the lever

The amount of energy required for movement

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Verified step by step guidance

Understand the concept of a lever: A lever is a rigid structure that rotates around a fixed point called the fulcrum. In the human body, bones act as levers, joints as fulcrums, muscles provide the effort, and the load is the resistance or weight being moved.

Learn the three classes of levers: These are classified based on the relative positions of the fulcrum, effort, and load. The classes are: First-class lever, Second-class lever, and Third-class lever.

First-class lever: The fulcrum is located between the effort and the load. An example in the human body is the movement of the head on the neck, where the neck joint acts as the fulcrum.

Second-class lever: The load is located between the fulcrum and the effort. An example in the human body is standing on tiptoes, where the ball of the foot acts as the fulcrum, the body weight is the load, and the calf muscles provide the effort.

Third-class lever: The effort is located between the fulcrum and the load. This is the most common type of lever in the human body. An example is the action of the biceps brachii during elbow flexion, where the elbow joint acts as the fulcrum, the biceps provide the effort, and the weight in the hand is the load.