[Morphology and topography of the carotid body and carotid sinus in sheep (Ovis ammon f. aries L., 1758)].

The studies were conducted on 60 preparations of 30 sheep heads. The objective of the work was to describe the form, structure, situation, innervation and blood supply of the carotid body and carotid sinus in the sheep. It results from the present study that the carotid body of the sheep is a single formation, of an oval, circular or irregular shape. In most cases it lies on the surface of the medial termination of the common carotid artery and is situated closer to or farther from one of the arteries which begin in this region. The size of the body varies between 1.4 and 2.6 mm in diameter. The initial part of the occipital artery and the posteriorly adjacent dorso-lateral and medial part of the common carotid artery were recognized as the homologue of the carotid sinus of other animals. The carotid body is innervated by the carotid sinus branch of the glossopharyngeal nerve and by the branches of the external carotid nerves. The carotid sinus is innervated by the nerves described above, by a branch of the vagus nerve (in 50% of cases) and by a branch of the hypoglossal nerve (in 23.3% of cases).