The topographical anatomy of the head and neck of the horse / [O. Charnock Bradley].
- Orlando Charnock Bradley
- Date:
- 1923
Licence: In copyright
Credit: The topographical anatomy of the head and neck of the horse / [O. Charnock Bradley]. Source: Wellcome Collection.
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![i at the entrance to the chest, where they are continuous with the cranial mediastinal glands of the thorax. Associated with the cervical lymph glands there is a relatively large lymphatic vessel (tracheal truvJc) on each side of the neck. This follows the common carotid artery across the lateral face of the trachea, and, on the right side of the body, can generally be followed to the caudal group of cervical glands. On the left it ends by joining the thoracic duct as this is entering the venous system. Dissection.—In order to obtain a clear view of the trachea, cut across the coinnion belly of the sterno-hyoid and sterno-thyroid muscles, and turn these aside. Ihp: trachea.—The trachea^ is a cartilaginous and membranous tube extending from the larynx (roughly from the level of the articula¬ tion between the atlas and the epistropheus) down the middle line of the neck and into the thorax, where it ends opposite the fifth or sixth inter¬ costal space by dividing into the right and left bronchi. In the neck the tube is slightly flattened dorso-ventrally, the dorso-ventral diameter, in an animal of average size, being about 5 cm., while the transverse diameter is about b cm. The width of the tube, is, however, not quite uniform, as there is a certain amount of narrowing in the neighbourhood of the larynx as well as near the thoracic inlet. The main relations of the trachea in the neck are as follows. At first the cesophagus is dorsal to the trachea, but later it passes towards the left, and the trachea then comes into contact with the longus colli muscle. On each side of the windpipe are the thyroid gland, the common carotid artery, the vagus, sympathetic and recurrent nerves, the lymph glands of the neck and the lymphatic vessels connected therewith, the omo-hyoid and scalene muscles, and, on the right side, the jugular vein. Ventral to the trachea are the sterno-cepbalic, sterno¬ hyoid, and sterno-thyroid muscles. The skeleton of the trachea consists of a variable number (48 to 55) of incomplete rings of cartilage (cartilagines tracheales) joined together by membranous and elastic ligaments (ligamenta annularia trachealia). The interruption in the continuity of each ring occurs in the dorsal part of the tube, where transverse muscular fibres (m. trachealis) occur. The first tracheal cartilage is joined to the cricoid cartilage of the larynx b}? the crico-tracheal ligament (ligamenturn cricotracheale), in series with, but looser than, the annular ligaments. The dissector should isolate one or two of the tracheal cartilages when he will find that they are thickest (2-8mm.) and narrowest in the • Tpaxeta (tracheia) [Or.], rough (artery).](https://iiif.wellcomecollection.org/image/b29820066_0023.jp2/full/800%2C/0/default.jpg)
