A morphological study of the carotid body and the fibre content of carotid nerve in the buffalo.

In the buffalo the carotid body is located in the periarterial connective tissue of the occipital artery immediately cranial to the bifurcation of the common carotid artery. The carotid body is lobulated and does not appear to contain chromaffin tissue. Nerve terminals have been seen in close relation to the glomus cells. A quantitative study of the fibre content of the carotid nerve and the carotid body has also been made. The myelinated fibres in the carotid nerve range from 278 to 473, with a mean of 368 +/- 39 fibres. The histogram of myelinated fibres is distinctly unimodal. Of the myelinated fibre population, 55.4% of fibres have diameters of 2 mum, 34.1% of 4 mum, 9.5% of 6 mum and 1% have diameters of 8 mum. The mean greatest sagittal sectional area of the carotid body is 0.58 +/- 0.09 mm2. The mean density (per mm2) of glomus cells is 9,216 +/- 378. It appears that the organ is highly vascular (473 +/- 56 blood vessels/mm2 area). The mean size of the glomus cells is 7.85 +/- 0.46 mum X 10.02 +/- 0.64 mum (short diameter X long diameter), whereas the mean size of their nuclei is 4.96 +/- 0.19 mum X 5.52 +/- 0.27 mum.