Full Title: Action of Tail when Elevated
Author: Kimberly Gradin
Date of Publication: October 31, 2011
Research Paper Text:
The report agreed upon with instructor, Jonathan, was regarding a specific articulation of the body. It was describing the action of the tail when elevated. I found this to be very difficult, just trying to find much on the tail itself. Here is what perseverance has taught me.
The soft tissues around the anus harden as muscles contract and press on the anal gland, also stretching the hamstring muscles. Every time a dog moves its tail it acts like a fan for scent. Therefore a dominant dog that carries his tail high will release much more natural scent from his anal glands than a dog that holds his tail lower.
The Sacrocaudalis muscles give mobility to the tail. The dog’s tail is elevated (extended) by contraction of the medial and lateral dorsal sacrocaudal muscles.
The dorsal sacrocaudal muscles get there name from being dorsally attached to the sacral and caudal (coccygeal) vertebrae, which is part of the axial skeleton. They are a small group of muscles in the hind limb area.
The lateral dorsal sacrocaudal muscle’s origin is a continuation of the longissimus, fleshy from aponeurosis of the longissimus and a tendinous origin from the mamillary processes of the first to sixth lumbar vertebra, the articular processes of the sacrum, and the mamillary processes of at least the first eight caudal vertebrae. Its insertion is mamillary processes of the fifth to last caudal vertebrae. The action is the extension or lifting of the tail, possibly also to move it to the side. The nerve innervations are branches of the plexus caudalis dorsalis (caudal and sacral nerves).
The medial dorsal sacrocaudal muscle’s origin is the small processes that are dorsolateral to the caudal edge of the caudal vertebrae. It is direct extension of the multifidus muscle. Its insertion is mamillary processes of the fifth through last caudal vertebrae. Its action is extension of the tail and possibly lateral flexion. The nerve innervations are also the branches of the plexus caudalis dorsalis (caudal and sacral nerves).
The medial caudal artery, and the bilaterally paired lateral caudal arteries (2), and branches of the caudal gluteal arteries are the 3 major sources of blood to the tail.
The ligaments attached are the dorsal sacroiliac ligament and the sacrotuberous ligament.
Basically when the dorsal sacrocaudal muscles contract, the tail elevates pressing on anal glands secreting the animals scent into the air. The sacral and caudal nerves supply the motion and feeling in the skin. The caudal and gluteal arteries supply blood to these muscles, and the dorsal sacroiliac and sacrotuberous ligaments keep it in line.