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The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal cord is hollow and contains a structure called the central canal, which contains cerebrospinal fluid.
The vertebral column, also known as the spinal column, spine or backbone, is the core part of the axial skeleton in vertebrate animals.The vertebral column is the defining and eponymous characteristic of the vertebrate endoskeleton, where the notochord (an elastic collagen-wrapped glycoprotein rod) found in all chordates has been replaced by a segmented series of mineralized irregular bones ...
Cauda equina syndrome, a rare disorder affecting the bundle of nerve roots (cauda equina) at the lower (lumbar) end of the spinal cord, is a surgical emergency. [3] Cauda equina syndrome occurs when the nerve roots in the lumbar spine are compressed, disrupting sensation and movement. [4] Nerve roots that control the function of the bladder and ...
A section of the human vertebral column, showing multiple vertebrae in a left posterolateral view. Each vertebra (pl.: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord.The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts.
Patellar reflex. Schematic representation of patellar tendon reflex (knee jerk) pathway. The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Many animals, most significantly humans, have been seen to have the patellar reflex, including dogs, cats, horses ...
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 nerves and ganglia, which lie outside the brain and the spinal cord. [1] The main function of the PNS is to connect the CNS to the limbs and organs ...
The evolution of nervous systems dates back to the first development of nervous systems in animals (or metazoans). Neurons developed as specialized electrical signaling cells in multicellular animals, adapting the mechanism of action potentials present in motile single-celled and colonial eukaryotes. Primitive systems, like those found in ...