Caprine haemolymph nodes: Its structure and functions

Abstract

Caprine haemal nodes were located in the thoracic, abdominal, costocervical vessels and pelvic retroperitoneal cavities. The shape and size of the haemal node was pea sheaped and 5mm in average diameter. The histological structure of haemolymph node was consisted of a capsule, subcapsular, sinuses, differentiated cortex and medulla with hilus. The two layers thick capsule was found around the parenchyma. Besides connective tissue fibres smooth muscle and blood capillaries were predominant in the innermost layer. CD4 and CD8 positive cells were mostly distributed in the subcapsular, inter follicular and within the outer dome shaped part of the haemal lymph node. B cells were found from date of birth. At birth the B cells were found in the medullary zone and form 2nd months the B cells were mostly found in the germinal center of the secondary follicles. Caprine haemal node, the distribution of lymph vessels and the finding of only efferent lymph channels were related to the roles of haemal nodes in blood storage by hemoconcentration and in immune defense mechanisms.