|Thoracic spinal nerve|
The plan of the cervical and brachial plexuses.
The spinal cord with spinal nerves.
The thoracic spinal nerve 2 (T2) is a spinal nerve of the thoracic segment.
It originates from the spinal column from below the thoracic vertebra 2 (T2).
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of the nerves and ganglia outside the brain and spinal cord. The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body. Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood–brain barrier, which leaves it exposed to toxins and mechanical injuries.
A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into the corresponding cervical, thoracic, lumbar, sacral and coccygeal regions of the spine. There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves. The spinal nerves are part of the peripheral nervous system.
The long thoracic nerve supplies the serratus anterior muscle. This nerve characteristically arises from the anterior rami of three spinal nerve roots: the fifth, sixth, and seventh cervical nerves (C5-C7) although the root from C7 may be absent. The roots from C5 and C6 pierce through the scalenus medius, while the C7 root passes in front of the muscle.
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being a lot larger than the upper. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region.
The intercostal nerves are part of the somatic nervous system, and arise from the anterior rami of the thoracic spinal nerves from T1 to T11. The intercostal nerves are distributed chiefly to the thoracic pleura and abdominal peritoneum and differ from the anterior rami of the other spinal nerves in that each pursues an independent course without plexus formation.
The white ramus communicans from Latin ramus (branch) and communicans (communicating) is the preganglionic sympathetic outflow nerve tract from the spinal cord.
Sympathetic, or autonomic, ganglia are the ganglia of the sympathetic nervous system. Ganglia are 20,000 to 30,000 afferent and efferent nerve cell bodies that run along on either side of the spinal cord. Afferent nerve cell bodies bring information from your body to the brain and spinal cord. Efferent nerve cell bodies bring information from the brain and spinal cord to the rest of the body. The cell bodies create long sympathetic chains that are on either side of the spinal cord. They also form para- or pre- vertebral gangalia of gross anatomy. The afferent nerve cell bodies brings information from the body to the brain. The efferent nerve cell bodies bring information from the brain to the body regarding perceptions of danger. This perception of danger can instigate the fight-or-flight response associated with the sympathetic nervous system. The fight-or-flight response is adaptive when there is a real and present danger which can be avoided or diminished through increased sympathetic activity. Sympathetic activity could be increased heart rate, dilated pupils, or sweaty palms, for example.The fight-or-flight response is maladaptive when the danger is imagined, prolonged, or when it lasts after the threat is over. When the intensity or duration of the response is excessive, the individual may meet criteria for a variety of psychological disorders. Neuroblastoma tumors can arise from the sympathetic ganglia tissue.
The lateral grey column is one of the three grey columns of the spinal cord ; the others being the anterior and posterior grey columns. The lateral grey column is primarily involved with activity in the sympathetic division of the autonomic motor system. It projects to the side as a triangular field in the thoracic and upper lumbar regions of the postero-lateral part of the anterior grey column.
The ventral ramus is the anterior division of a spinal nerve. The ventral rami supply the antero-lateral parts of the trunk and the limbs. They are mainly larger than the dorsal rami.
The thoracic spinal nerve 1 (T1) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 3 (T3) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 4 (T4) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 5 (T5) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 6 (T6) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 7 (T7) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 8 (T8) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 9 (T9) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 10 (T10) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 11 (T11) is a spinal nerve of the thoracic segment.
The thoracic spinal nerve 12 (T12) is a spinal nerve of the thoracic segment.
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