Lab 4 - External and Internal Anatomy of the Spinal Cord

Microscopic Sections of Spinal Cord - Introduction

In this part of the lab you will be working with microscopic images of spinal cord sections. Work with these images to gain an appreciation of the relative position, shape and size of the nuclear groups and of the different levels of the spinal cord.

Microscopic Sections of Spinal Cord - IntroductionMicroscopic Sections of Spinal Cord - Introduction

In distinguishing spinal cord levels the following are useful to remember:

  1. Rostral regions have more white matter because ascending fibers have accumulated from all cord levels and descending fibers have not yet dispersed to their terminations. Conversely, caudal regions have less white matter.
  2. In regions supplying the limbs and digits (i.e., the cervical and lumbar enlargements), the gray horns are large because they provide a higher density of innervation of skin and muscle. This is because the limbs and digits have increased sensory acuity and discrete motor control.
  3. The lateral horn is present only at thoracic and lumbar levels.
  4. The posterior intermediate sulcus subdivides the posterior funiculus at levels above T6.