The Neck & The 7 Cervical Vertebrae

To read the complete article click here 178 – September, 2012

By Wendell Sammet

The function of the seven cervical vertebrae in a dog is to support the head and protect the spinal cord. It is constructed in a gentle “S” curve allowing the head to be arched upwards and backwards, so the head can be held facing the direction of movement, and also allowing forward flexion to reach the ground for sniffing and eating.

The first cervical vertebrae is called the Atlas. It’s function allows the up and down motion of the head on the neck. The Atlas has a very small body that is joined by thick, long transverse processes called “wings”. These wings are attached to powerful neck muscles responsible for the arching of the neck. The Atlas articulates with the Occiput of the head. It is these articular surfaces that allow for the hinge-like up-and-down movement of the skull on the neck.

The second cervical vertebrae is called the Axis. Its function allows the rotary movement of the head on the neck. The Axis has a unique horn-like projection which is the Odontoid Process. The Odontoid Process has an articular surface that articulates with the corresponding articulate surface of the Atlas. This structure allows the rotation of the Atlas about the Axis and most of the head rotation. The spine of the Axis is very pronounced and prominent.

The last five cervical vertebrae are all similar with a prominent body structure, with rather short transverse processes and spinous processes. The spinous process starts on the third vertebrae, facing upwards toward the head. The remaining four processes flow in the same manner, lengthening with the sixth and seventh standing straight up.

The junction of the Atlas and Axis, joined with the five cervical vertebrae form the Pole, which shows a pronounced bend in the arch of the neck. These cervical vertebrae are joined by the intervertebral disc of ribocartilage.

The necks topline starts at the junction of the skull, continuing with a slight curve called the arch, and blends smoothly into laid-back shoulders.

A neck should be in proportion to the balance of the animal. It should be strong and long enough allowing the head to be carried in its proper position. A neck that joins smoothly into laid-back shoulders will exhibit a faultless appearance.

The neck that is set onto steep shoulders will be short and out of proportion. The short neck will appear stuffy, blocky, often covered with heavy, short, thick muscles, with no elegance. A throaty neck has loose skin in the dew lap area and generally accompanies the short neck!

The ewe neck is concave on the neckline, without an indication of an arch, and it abruptly joins the shoulders and back. The circumference of the neck is usually equal from top to bottom. An ewe neck lacks muscle and support.

Each breed has its individual description of the neck, associated with that breeds type of working ability.

The Pointer states that the head should be carried high, the purpose (for view of the terrain and to give better balance for quick changes in direction).

When the German Shepherd is at attention or excited, the head is raised and the neck carried high, otherwise typical carriage of the head is forward rather than up, and a bit higher than the top of the shoulders, particularly in motion.

The Saint Bernard’s neck is set high, very strong and, when alert, is carried errect. Otherwise, it is carriered horizontally or slightly downward. The junction of the head and neck is distinctly marked by an indentation. The nape of the neck is very muscular and rounded at the sides which make the neck appear rather short.

The Poodle’s neck is well-proportioned, strong and long enough to permit the head to be carried high with dignity. The skin should be snug at the throat. The neck rises from strong, muscular shoulders.

The cervical ligament is the most important factor in the function of the neck. It is a unique ligament composed of two parts. The first is a strong stretchable cord attached at the occiput of the skull running down the back of the neck attaching itself to the fourth dorsal vertebrae. The second part hangs onto the cervical ligament as a fan-like structure which radiates off and attaches itself to four cervical vertebrae below the pole. This portion of the ligament controls the position of the head and integrates with the third vertebrae to provide the basic strength to the forward reach of the dog’s front leg.

An important muscle of the neck is called the Brachiocephalicus muscle. This muscle coincides with the length of the neck, attaching itself just below the shoulder joint onto the upper arm (the humerus).

When the head is moved higher during locomotion, the Brachiocephalicus muscle is tightened and it assists the leg in excessive forward reach.

There are numerous muscles in this action, but mainly they act in accordance with the principal muscle, the Brachiocephalicus.

Muscles play a great part in the dogs appearance and movement. The bones of the dog are helpless in movement without the assistance of muscles.

Muscles are like fleshy elastic bands. They are activated by nerves that contract and elongate, assisting in moving bones.

It is rare for a muscle to produce an action on its own. It normally functions as one component or a group of muscles. Muscles can only produce movement when they contract – when a muscle relaxes, movement does not occur unless the part which has been moved is acted upon by the contraction of another group of muscles (or is affected by the pull of gravity). These attributes suggest that muscles are almost always arranged in opposing (antagonistic) groups performing opposite actions on any given joint. Cooperation between opposing muscle groups is an especially important function of overall muscle activity.

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