The =panniculus carnosus= consists of two layers which cross each other
obliquely. The fibers of the superficial layer are directed nearly
vertically, those of the deep layer toward the face, on which they are
continued to form the facial portion.
The =mastoido-humeralis= is described on p. 314.
The =sterno-cephalicus= (Sterno-mastoideus) arises on the sternum and is
inserted by a long round tendon on the mastoid process.
The thyroid portion of the =sterno-thyro-hyoideus= has a peculiar
arrangement. It arises (separately from the opposite muscle) on the
manubrium sterni. About the middle of the neck it has an oblique
tendinous intersection, beyond which it divides into two branches; one
of these is inserted in the usual fashion, the other ends on the
laryngeal prominence. The hyoid portion is well developed.
The =omo-hyoideus= is thin. It arises as in the horse, but has no
connection with the mastoido-humeralis nor with the opposite muscle.
The =omo-transversarius= arises on the first or second cervical vertebra
(under cover of the mastoido-humeralis), and is inserted into the lower
part of the scapular spine.
There are two =scaleni=. The =scalenus ventralis= (s. primæ costæ)
resembles that of the ox, is attached to the last four cervical
vertebræ, and is perforated by the nerves of the brachial plexus. The
=scalenus dorsalis= (s. supracostalis) arises on the transverse
processes of the third to the sixth cervical vertebra, and ends on the
third rib.
[Illustration:
FIG. 226.—SUPERFICIAL MUSCLES OF PIG, AFTER REMOVAL OF PANNICULUS
CARNOSUS.
_a_, Levator nasolabialis; _b_, levator labii superioris proprius;
_b′_, fleshy slip of _b_ which comes from premaxilla; _c_,
dilatator naris lateralis; _d_, depressor rostri; _e_, orbicularis
oris; _f_, depressor labii inferioris; _g_, zygomaticus; _h_,
masseter; _i_, _i′_, _i″_, brachiocephalicus (cleido-occipitalis,
cleido-mastoideus, pars clavicularis); _k_, sterno-cephalicus;
_l_, sterno-hyoideus; _m_, omo-transversarius; _n_, _n′_,
trapezius; _o_, anterior deep pectoral; _p_, latissimus dorsi;
_q_, lumbo-dorsal fascia; _r_, obliquus abdominis externus; _r′_,
aponeurosis of _r_; _s_, serratus posticus; _t_, serratus magnus;
_u_, posterior deep pectoral; _v_, supraspinatus; _w_, _w′_,
deltoideus; _x_, long head of triceps; _y_, external head of
triceps; _z_, tensor fasciæ antibrachii; _1_, brachialis; _2_,
extensor carpi radialis; _3_, extensor digiti quarti; _4_,
extensor digiti quinti; _5_, extensor carpi ulnaris; _6_, ulnar
head of deep flexor; _7_, gluteus medius; _8_, tensor fasciæ latæ;
_9_, _10_, _10′_, biceps femoris; _11_, semitendinosus; _12_,
semimembranosus; _13_, caudal muscles; _14_, panniculus adiposus
in section. (After Ellenberger, in Leisering’s Atlas.)
]
The =straight muscles= of the head present no special features.
The =longus colli= is separated from the opposite muscle, so that part
of the bodies of the cervical vertebræ is exposed as in man.
The =intertransversales= resemble those of the ox.
The =splenius= is thick and extensive. It ends in three parts on the
occipital, the temporal, and the wing of the atlas (inconstant).
The =trachelo-mastoideus= is small, and its atlantal portion is blended
with the longissimus.
The =complexus= is large, and is clearly divided into two portions: the
dorsal portion (Biventer cervicis) is marked by several tendinous
intersections; the ventral part is the complexus proper.
The =obliquus capitis posterior= is relatively thin.
The =recti capitis= are thick and more or less fused.