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 two muscles are primarily responsible for pronating the forearm and turning the palm downward?

Flexor carpi radialis and extensor carpi ulnaris

Supinator and anconeus

Biceps brachii and brachialis

Pronator teres and pronator quadratus

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Verified step by step guidance

Understand the concept of pronation: Pronation refers to the movement of the forearm that turns the palm downward or posteriorly when in anatomical position. This involves the rotation of the radius over the ulna.

Identify the muscles involved in pronation: The two primary muscles responsible for pronation are the pronator teres and pronator quadratus. These muscles work together to rotate the radius over the ulna.

Locate the pronator teres: The pronator teres is a superficial muscle located in the forearm. It originates from the medial epicondyle of the humerus and the coronoid process of the ulna, and inserts onto the lateral surface of the radius.

Locate the pronator quadratus: The pronator quadratus is a deep muscle located near the wrist. It originates from the anterior surface of the distal ulna and inserts onto the anterior surface of the distal radius.

Understand the action of these muscles: The pronator teres is responsible for initiating pronation, while the pronator quadratus completes the movement, especially during forceful pronation. Together, they turn the palm downward effectively.