MUSCULI PTERYLARUM [SUBCUTANEI] - Annotations
(6) M. constrictor colli. Synonymy: M. cutaneus colli (Fujioka,1963; Zweers,1982); M. dermohyoideus (Zweers,1982); M. dermodorsalis (Burt,1930); see also Homberger and Meyers (1989). M. constrictor colli (Fig. 6.3) is the most superficial of the muscles underlying the cervical pterylae and is typically a thin and rather loosely organized sheet of muscle fasciculi, oriented in the transverse (circumferential) plane, opposite the cranial half or less of the neck; in some taxa more extensively caudally. Separate muscle bundles are most organized ventrally where they attach on either side of a median ventral raphe of the neck, but more widely spaced dorsally and caudally where they terminate in superficial fascia and a dorsal median raphe. The most rostral bundles may also attach to the cranium, especially on the caudal and dorsal rim of the external acoustic meatus where they blend with the attachment of M. cucullaris capitis (Annot. 7). The entire muscle typically receives its major innervation from R. cervicalis, N. hyomandibularis of the facial nerve (PNS Annot. 24), near the cranial attachment.
M. constrictor colli, pars intermandibularis. Synonymy: M. basibranchialis mandibularis, pars superficialis (Vanden Berge,1975); M. intermandibularis ventralis, pars caudalis (Zweers,1974,1982); see also Homberger and Meyers (1989). There appear to be two major variations in this specific muscular slip (Figs. 6.3, 6.7). In one variation, it is described as a fleshy band or sheet of muscle, forming the rostralmost fibers of the constrictor colli. In another variation, the slip attaches on the lateral aspect of the Proc. retroarticularis of the mandible (Osteo. Annot. 49), adjacent (caudal) to the attachment of M. serpihyoideus. In either case, it meets its counterpart in a midventral raphe, united with the caudal edge of M. intermandibularis ventralis (Annot. 26) and/or with the deeper hyobranchial muscles (M. intermandibularis dorsalis; M. serpihyoideus, Annot. 26,27). Pars intermandibularis should be used for either variant based on evidence that the craniocervical part of M. constrictor colli, M. serpihyoideus, and M. stylohyoideus have a common basis in development (Noden,1983) and innervation (N. facialis).
(7) M. cucullaris capitis. Synonymy: "Cucullus", L., hood or cowl; M. dermotemporalis (Homberger and Meyers,1989). An extensive sheet of muscle fibers oriented longitudinally between M. constrictor colli and M. cucullaris cervicis, deep to the lateral cervical apterium, resembling a hood over the caudal aspect of the head and neck (Figs. 6.3). The attachments on the skull include the dense membrane superficial to the jaw muscles within Fossa temporalis (Osteo. Annot. 104), the rim of Meatus acusticus externus (Osteo. Annot. 19) and the surface of Os squamosum, dorsal to these (see Fossa muscularis, Butendieck, 1980); the caudal extension of the belly typically consists of a middorsal and midventral raphe and three slips, Pars interscapularis, Pars propatagialis, and Pars clavicularis (Annot. 8, 9, and 10). The motor innervation is principally from the accessory nerve via the external ramus of the vagus nerve (PNS Annot. 27). See Vanden Berge (1975) for additional information.
M. cucullaris cervicis. Pars nuchalis is typically a loose arrangement of three to six widely spaced, oblique, ribbonlike fasciculi some of which attach on Proc. costalis of the most caudal series of cervical vertebrae (Osteo. Annot. 118). Pars
clavicularis is a more or less separate sheet of muscle which is attached to the clavicle. Both parts are attached on Pars interscapularis of the Pteryla dorsalis (Integ. Annot. 58) intermingling with the interscapular parts of M. cucullaris and M. latissimus dorsi (Annot. 8).
(8) M. cucullaris capitis, pars interscapularis. Synonymy: M. dermospinalis (Owen,1842). Dorsal terminal part of M. cucullaris capitis inserting into Pars interscapularis of the Pteryla dorsalis (Integ. Annot. 58) where it may overlap, or unite by means of a tendinous intersection (Annot. 2), with M. latissimus dorsi, pars interscapularis and M. cucullaris cervicis (Annot. 7; Berger, 1966; Osborne, 1968).
(9) Pars propatagialis: M. cucullaris capitis, M. pectoralis, and M. biceps brachii. All three are fleshy slips which insert, together with Pars propatagialis, M. deltoideus (Annot. 78), on Lig. propatagiale (Arthr. Annot. 141); see Fig. 6.13. The propatagial slip of M. cucullaris capitis is well-developed in psittacines, woodpeckers, and passerines. That of M. biceps brachii also inserts on Lig. limitans cubiti (Arthr. Annot. 141). In other avian taxa, additional muscle fibers from M. cucullaris capitis ("P. omocutaneus," Osborne,1968) insert on Pars scapulohumeralis of the Pteryla alaris (Integ. Annot. 64, 65) and one or more of the fleshy slips may attach on dense fascia of the shoulder. In some taxa, these three slips may be partly aponeurotic or even absent (see, e.g., "biceps slip," Hudson and Lanzillotti, 1964; Vanden Berge, 1970). See also Annot. 75 and 83.
(10) M. cucullaris capitis, pars clavicularis. Synonymy: Mm. claviculohyoideus and claviculoglandularis mandibularis externus anterior (Zweers, 1982). A ventral terminal part of cucullaris capitis inserting principally on the clavicle. In those birds which have a pendulant crop (Ingluvies, Digest. Annot 24), e.g., tinamous, galliform birds, the hoatzin, sandgrouse, pigeons and doves, and psittacines, Pars clavicularis may form superficial and deep sheets which ensheath this organ and support it in a sling-like fashion ("M. levator ingluviei", Furbringer,1888).