Spinal Cord Flashcards

Study spinal cord anatomy, including its segments, enlargements, gray and white matter, nerve roots, blood supply, and major pathways.

Card 1 of 30Question

What is the spinal cord?

The elongated portion of the central nervous system extending from the medulla oblongata through the vertebral canal.

In This Section

1. What is the spinal cord?

The elongated portion of the central nervous system extending from the medulla oblongata through the vertebral canal.

2. At which anatomical landmark does the spinal cord become continuous with the medulla oblongata?

The foramen magnum, near the pyramidal decussation.

3. At approximately which vertebral level does the spinal cord terminate in adults?

Near the L1 to L2 vertebral level.

4. What is the conus medullaris?

The tapered inferior end of the spinal cord.

5. What is the filum terminale?

A slender fibrous extension of the pia mater that helps anchor the spinal cord inferiorly.

6. What is the cauda equina?

A collection of lumbar, sacral, and coccygeal spinal nerve roots descending below the conus medullaris.

7. How many pairs of spinal nerves arise from the spinal cord?

31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.

8. What is a spinal cord segment?

A region of the spinal cord associated with the attachment of one pair of spinal nerves.

9. Why do lower spinal cord segments lie above their corresponding vertebrae in adults?

The vertebral column grows proportionally longer than the spinal cord during development.

10. What are the two major enlargements of the spinal cord?

The cervical enlargement and lumbosacral enlargement.

11. What is the functional significance of the cervical enlargement?

It contains increased numbers of neurons associated with innervation of the upper limbs.

12. What is the functional significance of the lumbosacral enlargement?

It contains increased numbers of neurons associated with innervation of the lower limbs.

13. How is gray matter arranged in a transverse section of the spinal cord?

As a central H-shaped or butterfly-shaped region surrounded by white matter.

14. What is the principal function of the anterior gray horn?

It contains somatic motor neurons that innervate skeletal muscles.

15. What is the principal role of the posterior gray horn?

Processing sensory information entering the spinal cord.

16. Where are sympathetic preganglionic neuron cell bodies primarily located in the spinal cord?

The intermediolateral cell column of the T1 to L2 spinal cord segments.

17. Where are sacral parasympathetic preganglionic neurons located?

The sacral parasympathetic nucleus in spinal cord segments S2 to S4.

18. What are the three white matter funiculi of the spinal cord?

Anterior, lateral, and posterior funiculi.

19. Which spinal nerve roots carry sensory information into the spinal cord?

The posterior or dorsal roots.

20. Where are the cell bodies of most primary sensory neurons of spinal nerves located?

The spinal or dorsal root ganglia.

21. Which spinal nerve roots carry motor fibers away from the spinal cord?

The anterior or ventral roots.

22. Which ascending spinal cord pathway conveys vibration, conscious proprioception, and discriminative touch?

The dorsal column-medial lemniscus pathway.

23. Which ascending pathway primarily carries pain and temperature sensations?

The lateral spinothalamic tract of the anterolateral system.

24. Which descending tract primarily controls voluntary movements of distal limb muscles?

The lateral corticospinal tract.

25. What is the central canal of the spinal cord?

A narrow, ependyma-lined channel continuous superiorly with the ventricular system.

26. Which three meningeal layers surround the spinal cord?

Dura mater, arachnoid mater, and pia mater.

27. What are the denticulate ligaments?

Lateral extensions of pia mater that attach to the dura mater and stabilize the spinal cord.

28. Which arteries provide the principal longitudinal arterial supply to the spinal cord?

One anterior spinal artery and two posterior spinal arteries.

29. What territory is primarily supplied by the anterior spinal artery?

Approximately the anterior two-thirds of the spinal cord, reinforced by segmental medullary arteries.

30. What is the great anterior segmental medullary artery?

The artery of Adamkiewicz, a major variable contributor to the blood supply of the lower spinal cord.