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

9. Muscle Tissue

Introduction to Muscles and Muscle Tissue

Anatomy & Physiology

9. Muscle Tissue

Introduction to Muscles and Muscle Tissue

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Multiple Choice

Which of the following is the major abductor muscle of the upper arm?

Biceps brachii

Deltoid

Latissimus dorsi

Pectoralis major

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Verified step by step guidance

Step 1: Understand the term 'abductor muscle'—an abductor muscle is responsible for moving a limb away from the midline of the body. In this case, the upper arm is being moved away from the torso.

Step 2: Review the anatomy of the upper arm and shoulder region. The major muscles involved in arm movement include the deltoid, biceps brachii, latissimus dorsi, and pectoralis major.

Step 3: Analyze the function of each muscle: - The deltoid muscle is primarily responsible for abduction of the arm at the shoulder joint. - The biceps brachii is involved in flexion and supination of the forearm, not abduction. - The latissimus dorsi is responsible for adduction, extension, and internal rotation of the arm. - The pectoralis major is involved in adduction and flexion of the arm.

Step 4: Identify the muscle that matches the function of abduction. Based on the analysis, the deltoid muscle is the major abductor of the upper arm.

Step 5: Confirm the answer by recalling that the deltoid muscle has three distinct parts (anterior, middle, and posterior fibers), with the middle fibers being primarily responsible for arm abduction.