Longissimus muscle
| Longissimus muscle |
|---|
|
| Back muscles of man |
| origin |
| Sacrum and vertebrae |
| approach |
| Vertebrae, ribs , temporal bone |
| function |
| Stretching and sideways bending of the spine |
| Innervation |
| Spinal nerves ( rami dorsales ) |
The longissimus muscle ( Latin for "longest muscle") is a skeletal muscle of the back that belongs to the so-called " local back muscles ", more precisely to the sacrospinal system ( systema sacrospinale ). It extends the entire length of the back, from the sacrum to the head. It lies between the iliocostalis muscle and the semispinalis muscle , these three muscles are also summarized as the erector spinae muscle ("straightener of the spine") and belong to the "epaxial" trunk muscles, so they lie on the back ( dorsal ) of the transverse processes of the vertebrae ( processus transversi ).
The M. longissimus dorsi is known in kitchen language as salmon in slaughtered animals .
structure
The longissimus muscle is divided into 4 (in horses 5) sections, which follow one another like a backdrop:
- Musculus longissimus lumborum ("longest muscle of the loin ")
- Musculus longissimus thoracis ("longest muscle of the chest ")
- Musculus longissimus cervicis ("longest muscle of the neck ")
- Musculus longissimus atlantis ("longest muscle of the atlas "): only in horses, occasionally in dogs
- Musculus longissimus capitis ("longest muscle of the head ")
The longissimus lumborum originates on the iliac and on the spinous processes of the vertebrae ( spinous processes ). The fiber course of the muscle fibers is head to the side ( craniolateral ). A split between the longissimus and iliocostalis muscles, known as the Bogorodsky intermediate tendon , descends from its strong fascia . It is practically impossible to separate the two muscles in the lumbar region. The muscle fibers attach to the transverse processes of the vertebrae, some muscle spikes also to the additional processes ( processus accessorii ).
The musculus longissimus thoracis also arises from the spinous processes and attaches to the additional and transverse processes as well as to the rib margins ( tuberositas musculi longissimi ). In the upper chest area (in animals correspondingly in the front) the muscle becomes narrower and the tendons attach to the tuberculum costae of the ribs.
The longissimus cervicis muscle arises from the transverse processes of the first 5 to 8 thoracic vertebrae and extends to the transverse processes of the last 3 to 5 cervical vertebrae.
A longissimus atlantis muscle is only evident in horses, and occasionally it also occurs in dogs. It runs below the longissimus capitis muscle and attaches to the atlas wing ( Ala atlantis ).
The longissimus capitis muscle arises from the transverse processes of the first thoracic and articular processes ( processus articulares ) of the last cervical vertebrae and attaches to the processus mastoideus of the temporal bone .
function
With bilateral contraction, the muscle causes the spine to straighten (stretch) (a hollow back, lordosis ) and lift the neck. With unilateral contraction, the spine is bent sideways (see also scoliosis ).
literature
- Franz-Viktor Salomon: muscle tissue. In: Anatomy for veterinary medicine. Enke, Stuttgart 2004, ISBN 3-8304-1007-7 , pp. 147-234.