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Lumbar Enlargement
The lumbar enlargement (or lumbosacral enlargement) is a widened area of the spinal cord that gives attachment to the nerves which supply the lower limbs. It commences about the level of T11 and ends at L2, and reaches its maximum circumference, of about 33 mm. Inferior to the lumbar enlargement is the conus medullaris. An analogous region for the upper limbs exists at the cervical enlargement The cervical enlargement corresponds with the attachments of the large nerves which supply the upper limbs. Located just above the brachial plexus, it extends from about the fifth cervical to the first thoracic vertebra, its maximum circumferen .... Additional images File:Slide5sese.GIF, Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view. References External links * * - "Vertebral Canal and Spinal Cord: Regions of the Spinal Cord" * - "Spinal Cord, Fetus, Posterior View" Spinal cord {{neuroscience-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerves
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon, within the nerve, is an extension of an individual neuron, along with other supportive cells such as some Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium. The axons are bundled together into groups called fascicles, and each fascicle is wrapped in a layer of connective tissue called the perineurium. Finally, the entire nerve is wrapped in a layer of connective tissue called the epineurium. Nerve cells (often called neurons) are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Limbs
The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males. Structure In human anatomy, the lower leg is the part of the lower limb that lies between the knee and the ankle. Anatomists restrict the term ''leg'' to this use, rather than to the entire lower limb. The thigh is between the hip and knee and makes up the rest of the lower limb. The term ''lower limb'' or ''lower extremity'' is commonly used to de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conus Medullaris
''Conus'' is a genus of predatory sea snails, or cone snails, marine gastropod mollusks in the family Conidae.Bouchet, P.; Gofas, S. (2015). Conus Linnaeus, 1758. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=137813 on 2015-11-12 Prior to 2009, cone snail species had all traditionally been grouped into the single genus ''Conus''. However, ''Conus'' is now more precisely defined, and there are several other accepted genera of cone snails. For a list of the currently accepted genera, see Conidae. Description The thick shell of species in the genus ''Conus'' sensu stricto, is obconic, with the whorls enrolled upon themselves. The spire is short, smooth or tuberculated. The narrow aperture is elongated with parallel margins and is truncated at the base. The operculum is very small relative to the size of the shell. It is corneous, narrowly elongated, with an apical nucleus, and the impr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Enlargement
The cervical enlargement corresponds with the attachments of the large nerves which supply the upper limbs. Located just above the brachial plexus, it extends from about the fifth cervical to the first thoracic vertebra, its maximum circumference (about 38 mm.) being on a level with the attachment of the sixth pair of cervical nerves 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 .... The reason behind the enlargement of the cervical region is because of the increased neural input and output to the upper limbs. An analogous region in the lower limbs occurs at the lumbar enlargement. References External links * * - "Vertebral Canal and Spinal Cord: Regions of the Spinal Cord" * - "Spinal Cord, Fetus, Posterior View" Nerves of the upper limb {{neuroscience- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
