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 Organ Systems

Anatomy & Physiology

1. Introduction to Anatomy & Physiology

Introduction to Organ Systems

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Multiple Choice

Which of the following structures is found within a muscle spindle?

Tendon organ

Myelin sheath

Motor end plate

Intrafusal muscle fibers

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Verified step by step guidance

Understand the context: Muscle spindles are specialized sensory organs located within skeletal muscles. They play a critical role in detecting changes in muscle length and are involved in proprioception, which is the body's ability to sense its position and movement.

Identify the components of a muscle spindle: Muscle spindles contain intrafusal muscle fibers, sensory nerve endings, and motor nerve endings. Intrafusal muscle fibers are the specialized muscle fibers within the spindle that detect stretch and send signals to the central nervous system.

Clarify why the other options are incorrect: Tendon organs (Golgi tendon organs) are located in tendons, not within muscle spindles. Myelin sheath is a protective covering around nerve fibers, but it is not a structure within the muscle spindle. The motor end plate is part of the neuromuscular junction, where motor neurons connect to muscle fibers, but it is not found within the muscle spindle.

Focus on the correct answer: Intrafusal muscle fibers are the key structural component within muscle spindles. They are surrounded by a capsule and work alongside sensory neurons to detect muscle stretch.

Summarize the concept: Muscle spindles are sensory organs containing intrafusal muscle fibers, which are essential for detecting changes in muscle length and contributing to reflexes like the stretch reflex.