II. Spinal Canal & Spinal Cord Relationship

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 nerve is an exception to this rule). 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 an exception to this rule). 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 same vertebral number at the costocentral joint rib 3 articulates with T3 segment and also with the T2 segment; only ribs 1, 11, and 12 typically joint with a single segment

Question 4

What is the relationship between spinal 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 relates to the lower segment number in the vertebral couple i.e. T3 nerve exits the intervertebral foramen formed by T3/T4 and rib 4 joints with this vertebral couple