Figure 13-45.

Structure of a Lymph Node.

1 and 2, Lymph node architecture consists of an outer cortex composed of lymphoid follicles (B lymphocytes), inner/deep paracortex (T lymphocytes), and medulla (medullary cords and sinus). Lower right, Histologic section. H&E stain. 3, Gross photograph of a lymph node: The cortex (both outer and inner) is pale tan-pink, and the medulla is dark red.

(Courtesy Dr. A.C. Durham, School of Veterinary Medicine, University of Pennsylvania; Dr. M.D. McGavin, College of Veterinary Medicine, University of Tennessee; and Dr. J.F. Zachary, College of Veterinary Medicine, University of Illinois.)