Physical Anatomy of the Equine Head & Neck

Posted in: Classical Equitation, Stories & Thoughts

I have spent enormous amounts of time through my life researching and learning about anatomy of the horse. I find it so interesting understanding what actually goes on beyond what we can see at face value by looking at the horse.

Unfortunately, it can be pretty scary – the more you understand, the more you realise that what we were taught when we learnt to ride or even what we are taught as adults as being THE accepted way of doing things, is actually pretty painful for the horse!

Anatomy of the horses head – this picture shows the anatomy of the outer surface of a horse’s head and top part of the neck. Interesting to look at but what struck me most of all was which of these are affected for instance when a crank noseband is used excessively tight or excessive pressure from a curb bit is applied – the obicularis oris, buccinator, masseter??

Nerves of the horses head – this picture shows the nerves in a horses head. This is even more scary when you think about a natural horsemanship halter with excessive pressure on it, or a bit in the horses mouth with excessive pressure being applied!

The Trigeminal has three branches:

Branch 1 – Mandibular Branch

This branch supplies sensation to the bone of the lower jaw, its teeth and to the related soft tissues of the tongue, chin, lips and gums. It also innervates the salivary glands and skin of the ear. It takes its name from the lower jaw or mandible and is known as the Mandibular Branch.

Branch 2 – Maxillary Branch

This second branch supplies the bone, teeth, hard palate, soft palate, nasal mucous membranes, lips and gums of the upper jaw or maxilla. Accordingly, it is known as the Maxillary Branch.

Branch 3 – Ophthalmic Branch

The third branch supplies sensation to the eye, eyelids, tear glands, skin of the forehead and the nearby nasal mucosa. This is known as the Ophthalmic Branch.

The bit

The action of the bit therefore can potentially trigger both acute and chronic pain along the course of the Trigeminal Nerve and down its 3 branches.

The pain may be transmitted directly to the brain or be initiated indirectly, by a process of feedback that results in what is known as referred pain. In this process, pain signals from any tributary of the Trigeminal Nerve which are in direct contact with the bit can spread to any other tributary of the same nerve, resulting in pain in areas of the face that actually have no direct contact with the bit at all.


My reason for posting this is not because I disagree with bits at all! I firmly believe that a bit introduced and explained to the horse systematically and then used correctly in light and soft, understanding, well educated hands without ever demonstrating a hint of backwards traction allows it to become a wonderful communication tool.

However, how many of us can put our hand on our hearts and honestly say our hands never, EVER use even the slightest of backwards traction, are soft, elastic, light and giving 100% of the time? And here inlies the possibility for pain as explained above.

To allow the bit to become this wonderful tool for exquisitely refined, feather-light, two-way communication which in turn results in complete self carriage in our horses requires the horse to be able to 1oo% trust the hands in which that bit sits never to cause pain.

Jo Hughes