Volume 2

General and descriptive anatomy of the domestic animals / by John Gamgee and James Law.

Date:
1861-1862
Catalogue details

Licence: Public Domain Mark

Credit: General and descriptive anatomy of the domestic animals / by John Gamgee and James Law. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    Form and situation. Structure. Origin. Insertion. Relations. Action. Form and position. Structure. Aponeuro- sis. Muscular part. Direction of its fibres. same animals it becomes attached to the internal tubercle of the head, and the lip of the bicipital groove, of the humerus. SECOND LAYER. Dissection.—Make a section of the trapezius at its middle part, and reflect its parts; do the same by the anterior portion of the aponeurosis of the latissimus dorsi, and the rhomboideus will be exposed. Rliomboideus posterior, (dorso subscapularis, Gir.; rhomboideus brevis, Per.)—This is a flattened quadrilateral muscle, situated upon the side of the withers, beneath the dorsal trapezius and the cartilage of the scapula. It is formed almost entirely of muscular fibres, which run parallel to each other, from its origin to its insertion. It arises from the summits of the second, third, fourth, fifth, and sometimes the sixth dorsal spines, and is inserted on the inner aspect of the cartilage of the scapula. Responding externally to the trapezius and scapular cartilage, the rhomboideus brevis is related by its internal aspect to a thick layer of yellow elastic tissue, which covers the aponeurosis of the anterior small serrated muscle of the back. This elastic membrane, which is intimately adherent to the structures between which it is interposed, is continued forwards over the tendinous aponeurosis of the splenius and complexus muscles, and by several prolongations into the substance of the serratus magnus. This muscle elevates the shoulder, and adducts the cartilage of the scapula. THIRD LAYER. Dissection.—To expose the third layer, the anterior limb must be removed, together with the rhomboideus posterior and latissimus dorsi. Serratus parvus anticus, (dorso-costalis, Gir.; anterior portion of the serratus longus, Bourgelat; superficialis-costarum,Percivall).—This is a thin, flat, quadrilateral muscle, situated beneath the rhomboideus brevis and the latissimus dorsi. It is aponeurotic at its origin, and fleshy at its insertion. The aponeurotic portion has its anterior border continuous with the fascia of the splenius; its posterior border insinuates itself beneath the aponeurosis of the posterior small ser- ratus with which it is confounded. It becomes muscular on a level with the outer border of the longissimus dorsi, and is terminated inferiorly by a series of digitations. The fibres run in a direction from above downwards and backwards.