Brachiocephalicus muscle
| Brachiocephalicus muscle |
|---|
| origin |
| Clavicle tendon strips |
| approach |
| Cleidobrachialis muscle: crista humeri cleidocephalicus muscle: head or neck |
| function |
| Extension of the shoulder joint, pulling the neck sideways or down |
| Innervation |
| Ramus dorsalis of the accessory nerve |
The brachiocephalicus muscle ( Latinized from ancient Greek Βραχιοκεφαλικός , "upper arm-head muscle") is a skeletal muscle of the shoulder girdle muscles in mammals with a rudimentary collarbone or not integrated into the shoulder girdle . As a result, it is not trained in humans. It is a flat muscle on the side of the neck and forms the upper border of the throttle groove .
Parts
The muscle is divided into two sections that merge on the sinewy rudiment of the clavicle (clavicle tendon strip , intersectio clavicularis ) or on the clavicle, which is isolated from the shoulder girdle and embedded in the muscle (for example in cats ). These are the
- Musculus cleidobrachialis ("collarbone-upper arm muscle") and the
- Musculus cleidocephalicus ("clavicle-head muscle").
The cleidobrachialis muscle arises from the clavicle tendon strip or the collarbone and pulls towards the humerus ( crista humeri ) of the humerus . Comparatively anatomically, it corresponds to the pars clavicularis of the musculus deltoideus in humans.
The cleidocephalicus muscle pulls from the clavicle tendon strip to the head, and in predators also to the neck. In humans it is part of the sternocleidomastoid muscle . The cleidocephalicus muscle can - depending on the species - have several attachment points, which is why the muscle is further subdivided according to the attachment:
- The pars mastoidea is typical of most mammals. It starts at the mastoid process of the temporal bone .
- The pars occipitalis occurs in addition to the pars mastoidea in cloven-hoofed animals . It starts at the neck line or the neck ridge ( linea or crista nuchae ) of the occiput .
- In predators, the pars cervicalis is the second part next to the pars mastoidea . It pulls to the connection seam of the muscles on the back of the neck and merges there with the corresponding muscle on the opposite side.
function
The brachiocephalicus muscle can move the front limb as well as the neck and head. With the head and neck fixed by other muscles, it stretches the shoulder joint and thus guides the front limb forward. If the forelimbs are fixed, it pulls the head and neck down when the two-sided contraction occurs, and to the side when it is unilateral.
literature
- Franz-Viktor Salomon: muscle tissue. In: Anatomy for veterinary medicine. 2nd ext. Edition. Enke Stuttgart, 2008, ISBN 978-3-8304-1075-1 , pp. 147-234.