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

25. The Urinary System

Introduction to the Urinary System

Anatomy & Physiology

25. The Urinary System

Introduction to the Urinary System

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Multiple Choice

Which of the following organisms have an excretory system that functions without a filtration step?

Mammals

Fish

Birds

Flatworms

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Verified step by step guidance

Understand the role of the excretory system: The excretory system is responsible for removing waste products from the body. In many organisms, this involves filtering blood or body fluids to remove waste products.

Identify the common excretory systems: In mammals, fish, and birds, the excretory system typically involves filtration through structures like kidneys, where blood is filtered to form urine.

Recognize the unique excretory system of flatworms: Flatworms, such as planarians, have a simple excretory system called protonephridia. This system does not involve a filtration step like in more complex organisms.

Explore the function of protonephridia: In flatworms, protonephridia consist of a network of tubules with flame cells that help in osmoregulation and waste removal. The flame cells use cilia to move waste fluids out of the body without a filtration process.

Conclude why flatworms do not require filtration: The absence of a circulatory system in flatworms means they do not need to filter blood. Instead, waste is directly expelled through the protonephridia, making their excretory system function without a filtration step.