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

15. The Special Senses

Structure of the Eyeball

Anatomy & Physiology

15. The Special Senses

Structure of the Eyeball

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Multiple Choice

Which structure controls the amount of light that enters the eye?

Lens

Retina

Iris

Cornea

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Verified step by step guidance

Understand the function of each structure in the eye: The lens focuses light onto the retina, the retina detects light and converts it into neural signals, the cornea helps to focus light, and the iris controls the amount of light entering the eye.

Identify the role of the iris: The iris is the colored part of the eye surrounding the pupil. It contains muscles that adjust the size of the pupil.

Explain how the iris works: The iris adjusts the size of the pupil in response to light intensity. In bright light, the iris constricts the pupil to reduce light entry. In dim light, it dilates the pupil to allow more light in.

Differentiate the iris from other structures: Unlike the lens, retina, or cornea, the iris directly regulates light entry by changing the pupil size.

Conclude that the iris is the structure responsible for controlling the amount of light entering the eye, as it adjusts the pupil size in response to light conditions.