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

12. The Central Nervous System

Introduction to the Central Nervous System

Anatomy & Physiology

12. The Central Nervous System

Introduction to the Central Nervous System

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Problem 9

Textbook Question

Which three pairs of descending tracts make up the corticospinal pathway?

Verified step by step guidance

Understand the corticospinal pathway: The corticospinal pathway is a major motor pathway responsible for voluntary movement. It consists of descending tracts that carry motor signals from the cerebral cortex to the spinal cord.

Identify the descending tracts: The corticospinal pathway is made up of three pairs of descending tracts, which are the lateral corticospinal tract, anterior corticospinal tract, and corticobulbar tract.

Learn the function of each tract: The lateral corticospinal tract controls fine motor movements of the limbs, the anterior corticospinal tract controls axial muscles (trunk and proximal muscles), and the corticobulbar tract influences cranial nerves for facial and head movements.

Understand the anatomical location: The lateral corticospinal tract is located in the lateral column of the spinal cord, the anterior corticospinal tract is found in the anterior column, and the corticobulbar tract terminates in the brainstem.

Review the pathway's origin and termination: The corticospinal tracts originate in the motor cortex of the brain and descend through the brainstem and spinal cord, while the corticobulbar tract terminates in the brainstem to interact with cranial nerves.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Corticospinal Pathway

The corticospinal pathway is a major neural pathway that originates in the cerebral cortex and descends to the spinal cord, playing a crucial role in voluntary motor control. It is primarily responsible for the execution of fine motor movements, particularly in the limbs. Understanding this pathway is essential for grasping how the brain communicates with the spinal cord to facilitate movement.

Descending Tracts

Descending tracts are bundles of nerve fibers that carry motor commands from the brain to the spinal cord and ultimately to the muscles. These tracts are crucial for voluntary movement and reflexes. In the context of the corticospinal pathway, identifying the specific descending tracts helps clarify how motor signals are transmitted and coordinated throughout the body.

Pyramidal and Extrapyramidal Systems

The pyramidal system, which includes the corticospinal pathway, is responsible for voluntary motor control, while the extrapyramidal system regulates involuntary and automatic control of muscles. The corticospinal pathway specifically consists of the lateral corticospinal tract and the anterior corticospinal tract, both of which are essential for different aspects of motor function. Understanding these systems aids in comprehending the overall organization of motor control in the nervous system.