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

10. Muscles

Muscle Actions

Anatomy & Physiology

10. Muscles

Muscle Actions

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Multiple Choice

Which of the following best describes how your arm muscles work to lift a mug of coffee to your lips?

The biceps brachii contracts to flex the elbow while the triceps brachii relaxes.

Both the biceps brachii and triceps brachii contract simultaneously to lift the mug.

The deltoid muscle alone is responsible for lifting the mug to your lips.

The triceps brachii contracts to flex the elbow while the biceps brachii relaxes.

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Verified step by step guidance

Step 1: Understand the anatomy of the arm muscles involved in lifting a mug. The biceps brachii is located on the front of the upper arm and is responsible for flexing the elbow, while the triceps brachii is located on the back of the upper arm and is responsible for extending the elbow.

Step 2: Recognize the concept of antagonistic muscle pairs. These pairs work in opposition to each other, where one muscle contracts (shortens) to produce movement, and the opposing muscle relaxes (lengthens) to allow the movement.

Step 3: Analyze the motion of lifting a mug to your lips. This action involves flexing the elbow joint, which decreases the angle between the forearm and upper arm. Flexion is primarily performed by the biceps brachii.

Step 4: Determine the role of the triceps brachii during this motion. Since the triceps brachii is responsible for extending the elbow, it must relax to allow the biceps brachii to contract and flex the elbow effectively.

Step 5: Eliminate incorrect options based on the anatomy and physiology of the muscles. For example, the deltoid muscle primarily abducts the arm at the shoulder and does not play a significant role in flexing the elbow. Similarly, simultaneous contraction of both the biceps brachii and triceps brachii would counteract the movement, making it inefficient.