Spinal canal and spinal cord relationships

Question 1

At the intervertebral foramen, what is the relationship between spinal nerve number and vertebral number along the cervical spine?

Answer 1

in the cervical spine, spinal nerves exit above the segment they are numbered after (C8 is exception) C3 nerve exits above C3 or between C2/C3

Question 2

At the intervertebral foramen, what is the relationship between spinal nerve number and vertebral number along the thoracic and lumbar spine and the sacrum?

Answer 2

In the thoracic and lumbar spine and for the sacrum, spinal nerves exit below the segment they are numbered after (Co1 nerve is the exception)
-T6 nerve exits below T6 or between T6/T7

Question 3

What is the relationship between rib number and vertebral numbers at the costocentral joint?

Answer 3

rib number always equates to the same vertebral number at the costocentral joint

• rib 3 articulates with the T3 segment and also with the T2 segment
• only ribs 1, 11, 12 typically joint with a single segment

Question 4

What is the relationship between spine nerve number, rib number and vertebral number in a thoracic intervertebral foramen?

Answer 4

the spinal nerve number relates to the upper segment number in the vertebral couple

• the rib number related to the lower segment number in the vertebral couple
• ex: T3 nerve exits the intervertebral foramen formed by T3/T4 and rib 4 joints with this vertebral couple