Thoracic nerves
Encyclopedia
The thoracic nerves are the spinal nerves emerging from the thoracic vertebrae
. Branches also exit the spine and go directly to the Sympathetic Chain Ganglia of the Autonomic Nervous System
where they are involved in the functions of organs and glands in the head, neck, thorax and abdomen.
and Multifidus, which they supply; they then pierce the Rhomboidei and Trapezius, and reach the skin by the sides of the spinous processes.
The medial branches of the lower six are distributed chiefly to the Multifidus and Longissimus dorsi, occasionally they give off filaments to the skin near the middle line.
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...
. Branches also exit the spine and go directly to the Sympathetic Chain Ganglia of the Autonomic Nervous System
Autonomic nervous system
The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
where they are involved in the functions of organs and glands in the head, neck, thorax and abdomen.
Anterior divisions
- The intercostal nervesIntercostal nervesThe intercostal nerves are the anterior divisions of the thoracic spinal nerves from T1 to T11.Each nerve is connected with the adjoining ganglion of the sympathetic trunk by a gray and a white ramus communicans...
come from thoracic nerves T1-T11, and run between the ribs ("costae"). At T2 and T3, it further branches into the intercostobrachial nerveIntercostobrachial nerve-Second intercostal nerve:The lateral cutaneous branch of the second intercostal nerve does not divide, like the others, into an anterior and a posterior branch; it is named the intercostobrachial nerve. It pierces the Intercostalis externus and the Serratus anterior, crosses the axilla to the...
.
- The subcostal nerveSubcostal nerveThe anterior division of the twelfth thoracic nerve is larger than the others; it runs along the lower border of the twelfth rib, often gives a communicating branch to the first lumbar nerve, and passes under the lateral lumbocostal arch.It then runs in front of the Quadratus lumborum, perforates...
comes from nerve T12, and runs below the twelfth ribTwelfth ribThe twelfth rib has a single articular facet on the head, which is of rather large size. It has no necks or tubercles, and is pointed at its anterior ends....
.
Posterior divisions
The medial branches (ramus medialis; internal branch) of the posterior divisions of the upper six thoracic nerves run between the Semispinalis dorsiSemispinalis dorsi
The Semispinalis dorsi consists of thin, narrow, fleshy fasciculi, interposed between tendons of considerable length....
and Multifidus, which they supply; they then pierce the Rhomboidei and Trapezius, and reach the skin by the sides of the spinous processes.
The medial branches of the lower six are distributed chiefly to the Multifidus and Longissimus dorsi, occasionally they give off filaments to the skin near the middle line.