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 muscle do you contract in order to straighten your back after bending at the waist?

Erector spinae

Rectus abdominis

Pectoralis major

Gluteus maximus

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Verified step by step guidance

Understand the function of each muscle listed in the problem: The erector spinae is a group of muscles responsible for extending the spine and straightening the back. The rectus abdominis is involved in flexing the spine (bending forward). The pectoralis major is primarily responsible for movements of the shoulder and arm. The gluteus maximus is involved in hip extension and stabilization.

Identify the action described in the problem: Straightening the back after bending at the waist requires spinal extension, which is the opposite of spinal flexion.

Determine which muscle group is responsible for spinal extension: The erector spinae muscles are the primary muscles involved in extending the spine and straightening the back.

Eliminate incorrect options: The rectus abdominis is involved in flexion, not extension. The pectoralis major is unrelated to spinal movement. The gluteus maximus contributes to hip extension but does not directly straighten the back.

Conclude that the erector spinae is the correct muscle group responsible for straightening the back after bending at the waist.