Fig. 3.—Superficial muscles concerned in the movements of the head and neck of the horse.
Fig. 4.—Deeper layer of the muscles concerned in the movements of the head and neck of the horse; the scapula removed.
The main facts of the anatomy of the horse’s neck must be referred to here, so that a better picture may be obtained as to the powerful forces which are found in conflict during the locomotive life of the animal. Fig. 3 shows the superficial layer of muscles concerned in the actions of its head and neck, and the manner in which adjoining muscles diverge from one another should be noted. Fig. 4 gives the deepest layer of neck-muscles, the shoulder-blade having been removed, and Fig. 5 the immensely strong ligamentum nuchae, of yellow elastic tissue, which extends from the base of the skull to the great projecting spinous process of the lowest cervical and second and third dorsal vertebræ.
Fig. 5.—Ligaments and tendons supporting the head and neck of the horse.
There are here indeed great forces for conflict—first a layer of strong superficial muscles, second a layer of smaller muscles which has not been figured, third a deep layer of muscles, and fourth a powerful, widely-spread and strongly-attached mass of dense elastic tissue, adapted for supporting the head without muscular exertion, but by its elasticity allowing a downward jerk of the head and neck at every step. It is an exceedingly important structure for a domestic horse.