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

13. The Peripheral Nervous System

Reflex Arcs

Anatomy & Physiology

13. The Peripheral Nervous System

Reflex Arcs

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Multiple Choice

How many synapses are involved in the knee-jerk (patellar) reflex arc?

Two

Four

Three

One

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Verified step by step guidance

Understand the knee-jerk (patellar) reflex arc: It is a simple reflex that involves the contraction of the quadriceps muscle in response to the stretching of the patellar tendon.

Identify the components of the reflex arc: The reflex arc includes a sensory neuron, a motor neuron, and the spinal cord as the integration center.

Recognize that the knee-jerk reflex is a monosynaptic reflex: This means there is only one synapse involved between the sensory neuron and the motor neuron.

Explain the pathway: The sensory neuron detects the stretch in the patellar tendon and sends an impulse to the spinal cord. In the spinal cord, the sensory neuron directly synapses with the motor neuron.

Conclude that the correct answer is 'One' because the knee-jerk reflex arc involves only one synapse between the sensory and motor neurons.