Which statement about the cervical enlargement is true?

Which statement about the cervical enlargement is true?

• A. C4-T1
• B. C2-C6
• C. C7-T1
• D. C1-C4

Answer: (A)

The cervical enlargement occurs where the spinal cord has increased gray matter to supply the nerves of the upper limb, primarily via the brachial plexus. This expansion includes the spinal cord segments that give rise to the nerves for the arm and hand, which are mainly from C5 to T1, with some contribution from C4. Therefore, the enlargement spans roughly from C4 to T1. This range best accounts for the neurons needed to control upper limb muscles. The other ranges either start too high, end too early, or miss portions of the segments that contribute to arm innervation, so they don’t fit the true extent of the enlargement.

The cervical enlargement occurs where the spinal cord has increased gray matter to supply the nerves of the upper limb, primarily via the brachial plexus. This expansion includes the spinal cord segments that give rise to the nerves for the arm and hand, which are mainly from C5 to T1, with some contribution from C4. Therefore, the enlargement spans roughly from C4 to T1. This range best accounts for the neurons needed to control upper limb muscles. The other ranges either start too high, end too early, or miss portions of the segments that contribute to arm innervation, so they don’t fit the true extent of the enlargement.