The intersegmental arteries are a set of 30 arteries arising from the embryonic dorsal aorta, [1] with each artery providing blood supply to one somite and its derivatives.
The cervical intersegmental arteries merge into the vertebral artery [1] with the exception of the 7th (or possibly the 6th) cervical intersegmental artery, which becomes the subclavian artery. [2] The confusion arises because the vertebral artery drains into the subclavian artery following the disappearance of the dorsal aortae in part of the cervical region.
The thoracic intersegmental arteries all develop into the intercostal arteries. [1]
The lumbar intersegmental arteries develop into the lumbar arteries, with the exception of the 5th (last) lumbar intersegmental artery, which becomes the common iliac arteries. [1]
These arteries merge into the lateral sacral artery. [1]
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.
In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.
In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. The thoracic duct usually begins from the upper aspect of the cisterna chyli, passing out of the abdomen through the aortic hiatus into first the posterior mediastinum and then the superior mediastinum, extending as high up as the root of the neck before descending to drain into the systemic (blood) circulation at the venous angle.
Neuromeres are morphologically or molecularly defined transient segments of the early developing brain. Rhombomeres are such segments that make up the rhombencephalon or hindbrain. More controversially, some argue that there exist early developmental segments that give rise to structures of the midbrain (mesomeres) and forebrain (prosomeres).
In tetrapods, cervical vertebrae are the vertebrae of the neck, immediately below the skull. Truncal vertebrae lie caudal of cervical vertebrae. In sauropsid species, the cervical vertebrae bear cervical ribs. In lizards and saurischian dinosaurs, the cervical ribs are large; in birds, they are small and completely fused to the vertebrae. The vertebral transverse processes of mammals are homologous to the cervical ribs of other amniotes. Most mammals have seven cervical vertebrae, with the only three known exceptions being the manatee with six, the two-toed sloth with five or six, and the three-toed sloth with nine.
The vertebral arteries are major arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, midline basilar artery. As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.
The stellate ganglion is a sympathetic ganglion formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion, which is present in 80% of individuals. Sometimes, the second and the third thoracic ganglia are included in this fusion.
The scalene muscles are a group of three pairs of muscles in the lateral neck, namely the anterior scalene, middle scalene, and posterior scalene. They are innervated by the third to the eight cervical spinal nerves (C3-C8).
The aortic arches or pharyngeal arch arteries are a series of six paired embryological vascular structures which give rise to the great arteries of the neck and head. They are ventral to the dorsal aorta and arise from the aortic sac.
Aberrant subclavian artery, or aberrant subclavian artery syndrome, is a rare anatomical variant of the origin of the right or left subclavian artery. This abnormality is the most common congenital vascular anomaly of the aortic arch, occurring in approximately 1% of individuals.
The thyrocervical trunk is an artery of the neck. It is a branch of the subclavian artery. It arises from the first portion of this vessel, between the origin of the subclavian artery and the inner border of the scalenus anterior muscle. It is located distally to the vertebral artery and proximally to the costocervical trunk. It gives off a number of branches to the neck. It helps to supply blood to the muscles of the neck.
The transverse cervical artery is an artery in the neck and a branch of the thyrocervical trunk, running at a higher level than the suprascapular artery.
Subclavian steal syndrome (SSS), also called subclavian steal steno-occlusive disease, is a constellation of signs and symptoms that arise from retrograde (reversed) blood flow in the vertebral artery or the internal thoracic artery, due to a proximal stenosis (narrowing) and/or occlusion of the subclavian artery. This flow reversal is called the subclavian steal or subclavian steal phenomenon, regardless of signs/symptoms being present. The arm may be supplied by blood flowing in a retrograde direction down the vertebral artery at the expense of the vertebrobasilar circulation. It is more severe than typical vertebrobasilar insufficiency.
The scapular anastomosis is a system connecting certain subclavian artery and their corresponding axillary artery, forming a circulatory anastomosis around the scapula. It allows blood to flow past the joint in case of occlusion, damage, or pinching of the following scapular arteries:
The deep cervical artery is an artery of the neck.
This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
The following outline is provided as an overview of and topical guide to human anatomy:
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around 45 cm (18 in) long in adult men and around 43 cm (17 in) long in adult women. The diameter of the spinal cord ranges from 13 mm in the cervical and lumbar regions to 6.4 mm in the thoracic area.
The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord found in all chordates has been replaced by a segmented series of bone: vertebrae separated by intervertebral discs. Individual vertebrae are named according to their region and position, and can be used as anatomical landmarks in order to guide procedures such as lumbar punctures. The vertebral column houses the spinal canal, a cavity that encloses and protects the spinal cord.
The spinal column, a defining synapomorphy shared by nearly all vertebrates, is a moderately flexible series of vertebrae, each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank, and on the other with phylogenetic differences among the vertebrate taxa.