Spinalis
Encyclopedia
The spinalis is the portion of the erector spinae
, a bundle of muscle
s and tendon
s, located nearest to the spine. It is divided into three parts.
It is situated at the medial side of the Longissimus dorsi, and is intimately blended with it; it arises by three or four tendons from the spinous processes of the first two lumbar and the last two thoracic vertebrae
: these, uniting, form a small muscle which is inserted by separate tendons into the spinous processes of the upper thoracic vertebræ, the number varying from four to eight.
It is intimately united with the Semispinalis dorsi
, situated beneath it.
, and occasionally into the spinous processes of the two vertebrae below it.
.
Erector spinae
The Erector spinæ is a muscle group of the back in humans and animals. It is also known as sacrospinalis in older texts. A more modern term is extensor spinae, though this is not in widespread use. The name of the muscle is pronounced e-rec-tor speen-aye, or e-rec-tor spinae-ee.It is really not...
, a bundle of muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s and tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
s, located nearest to the spine. It is divided into three parts.
Spinalis dorsi
The Spinalis dorsi, the medial continuation of the Sacrospinalis, is scarcely separable as a distinct muscle.It is situated at the medial side of the Longissimus dorsi, and is intimately blended with it; it arises by three or four tendons from the spinous processes of the first two lumbar and the last two thoracic vertebrae
Thoracic vertebrae
In human anatomy, twelve thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper...
: these, uniting, form a small muscle which is inserted by separate tendons into the spinous processes of the upper thoracic vertebræ, the number varying from four to eight.
It is intimately united with the Semispinalis dorsi
Semispinalis dorsi
The Semispinalis dorsi consists of thin, narrow, fleshy fasciculi, interposed between tendons of considerable length....
, situated beneath it.
Spinalis cervicis
The Spinalis cervicis (Spinalis colli) is an inconstant muscle, which arises from the lower part of the ligamentum nuchæ, the spinous process of the seventh cervical, and sometimes from the spinous processes of the first and second thoracic vertebrae, and is inserted into the spinosus process of the axisAxis (anatomy)
In anatomy, the second cervical vertebra of the spine is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head, rotates....
, and occasionally into the spinous processes of the two vertebrae below it.
Spinalis capitis
The Spinalis capitis (Biventer cervicis) is usually inseparably connected with the Semispinalis capitisSemispinalis capitis
The Semispinalis capitis is situated at the upper and back part of the neck, deep to the Splenius, and medial to the Longissimus cervicis and capitis....
.
