Fig. 3.1 Surface features: left lateral view. The palpable bony ‘landmarks’ of the neck are shown. The hyoid, larynx and trachea are clearly palpable on the underside of the neck. Soft structures which are occasionally palpable include the mandibular and superficial cervical lymph nodes. The external jugular vein may be raised by pressure in the jugular fossa at the thoracic inlet.

Fig. 3.2 Skeleton: left lateral view. The palpable bony features shown in Fig. 3.1 are colored green on this diagram for reference. However, any features of cervical vertebrae 3 to 7 are, even in thin dogs, only palpable with difficulty, and not at all in larger breeds.

Fig. 3.3 Radiograph of the neck: left lateral view. The major structural features of the neck are shown in this and the following radiograph. Both give clear views of the vertebral canal housing the spinal cord. The atlanto-occipital space extends inwards to the atlanto-occipital membrane spanning the gap between the dorsal arch of the atlas and the dorsal border of the foramen magnum. The space is enlarged when the head is bent down on the neck providing access to the vertebral canal through the atlanto-occipital membrane.

Fig. 3.4 Radiograph of the neck: ventrodorsal view. This radiograph shows the position of transverse processes, especially the readily palpable wings of the atlas. It also demonstrates the variety of joints providing the extensive mobility of the head and neck – (i) overlapping synovial joints between articular processes of contiguous vertebrae; (ii) cartilaginous (radiolucent) intervertebral discs between vertebral bodies; (iii) atlanto-occipital joint at the occipital condyles allowing up and down movements of the head on the neck; (iv) atlantoaxial joint based on the pivotal peg of the dens allowing rotational movement of the head on the neck. The absence of a clavicle is clearly apparent in this view of the shoulder.

Fig. 3.5 Radiograph of the larynx: lateral view. The laryngeal cartilages are poorly visible as ill-defined soft tissue opacities highlighted by the air within the larynx. The tympanohyoid bone is cartilaginous and so not visible against the retropharyngeal soft tissues.

Fig. 3.6 Superficial structures (1). Superficial fascia, cutaneous muscles and cutaneous nerves: left lateral view. The superficial fascia of the neck is exposed following removal of the skin. It continues cranially (over temporal, parotid and masseteric regions) as the superficial fascia of the head, and caudally as the superficial brachial and pectoral fascia. Exposed are the prominent platysma muscle and some isolated strands of the superficial sphincter colli muscle.

Fig. 3.7 Superficial structures (2). Cutaneous muscles and cutaneous nerves: dorsal view. The two components of the platysma muscle can be seen as a number of separate strands originating from the mid-dorsal line of the neck, and as a more substantial component arising from the internal surface of the skin itself. The two join dorsolaterally on the neck. The cutaneous branches from the dorsal rami of the cervical spinal nerves appear close to the mid-dorsal line and spread over the platysma surface.

Fig. 3.8 Superficial structures (3). Cutaneous nerves and external jugular vein: left lateral view. The platysma muscle has been removed, and the superficial fascia cleared, to expose the underlying muscles, and isolate cutaneous ramifications of cervical nerves 2, 3 and 4. Cervical nerve 5 lacks lateral cutaneous branches, whilst cervical nerves 6, 7 and 8 contribute to the brachial plexus (see Fig. 3.19). Cutaneous branches from cervical nerve 4 distribute to the base of the neck.

Fig. 3.9 Superficial structures (4). Cutaneous nerves, external jugular vein and jugular fossa: left craniolateral view. This clearly demonstrates the jugular fossa at the base of the neck and the deep and somewhat triangular depression bounded by sternocephalic, brachiocephalic and superficial pectoral muscles (see also Fig. 3.41). Also evident is the clavicular intersection within the brachiocephalic muscle, denoted by an indistinct fascial line lateral to the jugular fossa.

Fig. 3.10 Superficial musculature: left lateral view. The loose superficial fascia in the prescapular region and the retromandibular fossa has been cleaned, and the cutaneous muscles removed. This has exposed the mandibular and parotid salivary glands, the mandibular lymph nodes, and the main tributaries of the external jugular vein.

Fig. 3.11 Omotransverse muscle and dorsal ramus of the accessory nerve: left lateral view. The pinna of the ear has been pulled forwards onto the head to expose the craniodorsal part of the neck. The cervicoauricular and cervicoscutular muscles have been cut from their attachments in the dorsal midline of the neck. The cleidocervical muscle has been removed from the lateral surface of the neck by cutting through its belly on a line with the dorsal border of the external jugular vein. This has exposed the full extent of the dorsal branch of the accessory nerve (XI) to the trapezius muscle.