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

4. Tissues & Histology

Introduction to Muscle Tissue

Anatomy & Physiology

4. Tissues & Histology

Introduction to Muscle Tissue

Previous problemNext problem

Struggling with Anatomy & Physiology?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

In a relaxed muscle, what is true about the width of the H zone?

The H zone is at its widest width.

The H zone disappears completely.

The H zone is the same width as the A band.

The H zone is at its narrowest width.

Previous problemNext problem

Verified step by step guidance

Understand the structure of a sarcomere, the functional unit of a muscle fiber. The sarcomere contains distinct regions: the A band, I band, H zone, and Z disc. The H zone is the central part of the A band where only thick filaments (myosin) are present.

Recall that the H zone changes width depending on the state of muscle contraction. In a relaxed muscle, the thick and thin filaments do not overlap extensively, leaving the H zone at its widest width.

Contrast this with a contracted muscle, where the thin filaments slide toward the center of the sarcomere, overlapping with the thick filaments and causing the H zone to narrow or disappear completely.

Eliminate incorrect options based on the above understanding: The H zone cannot be the same width as the A band because the A band includes both thick and thin filaments, while the H zone contains only thick filaments. Similarly, the H zone cannot be at its narrowest width in a relaxed muscle.

Conclude that in a relaxed muscle, the H zone is at its widest width because the filaments are not overlapping significantly.