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 Directional Terms

Anatomy & Physiology

1. Introduction to Anatomy & Physiology

Introduction to Directional Terms

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Multiple Choice

Which of the following best describes the movements of protraction and retraction?

Protraction moves a body part forward along a horizontal plane, while retraction moves it backward.

Protraction moves a body part upward, while retraction moves it downward.

Protraction bends a joint, while retraction straightens it.

Protraction rotates a limb away from the midline, while retraction rotates it toward the midline.

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Verified step by step guidance

Step 1: Begin by understanding the definitions of protraction and retraction. Protraction refers to the movement of a body part forward along a horizontal plane, while retraction refers to the movement of a body part backward along the same plane.

Step 2: Identify the anatomical regions where protraction and retraction commonly occur. These movements are most often associated with the scapula (shoulder blade) and the mandible (jaw). For example, protraction of the scapula involves moving the shoulder blades forward, as in reaching forward, while retraction involves pulling them backward, as in pinching the shoulder blades together.

Step 3: Eliminate incorrect options based on the definitions. For example, protraction does not involve upward movement, bending a joint, or rotating a limb away from the midline. Similarly, retraction does not involve downward movement, straightening a joint, or rotating a limb toward the midline.

Step 4: Match the correct description to the definitions provided. The correct answer should align with the movement of a body part forward (protraction) and backward (retraction) along a horizontal plane.

Step 5: Confirm your understanding by visualizing or performing the movements. For instance, you can simulate protraction and retraction of the scapula by moving your shoulders forward and backward, respectively, to reinforce the concept.