Cytology 09

The two very large cells are alpha-motor neurons in the ventral horn of the spinal cord. The arrow to the cell at A indicates the nucleolus, within the typically large and euchromatic nucleus of this cell. The arrow to the cell at B indicates Nissl bodies (aggregates of free ribosomes and rough ER) also typical of these neurons. If you have access to the slide in the microscope, focus up and down to form an impression of how the nuclei of these cells are surrounded by Nissl bodies in 3-dimensions.

Slide A-9, 63X objective