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An axon (from Greek ἄξων áxōn, axis) or nerve fiber (or nerve fibre: see spelling differences) is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different ...
When the muscle fibre is relaxed (before contraction), the myosin head has ADP and phosphate bound to it. When a nerve impulse arrives, Ca 2+ ions cause troponin to change shape; this moves the troponin + tropomyosin complex away, leaving the myosin binding sites open. The myosin head now binds to the actin myofilament.
C fibers respond to all kinds of physiological changes in the body. [8] For example, they can respond to hypoxia, hypoglycemia, hypo-osmolarity, the presence of muscle metabolic products, and even light or sensitive touch. [8] C fiber receptors include: C fiber nociceptors responsible for the second, burning pain; C fiber warming specific receptors
Association fibers are axons (nerve fibers) that connect cortical areas within the same cerebral hemisphere. [1]In human neuroanatomy, axons within the brain, can be categorized on the basis of their course and connections as association fibers, projection fibers, and commissural fibers. [1]
Fibroblasts can also migrate slowly over substratum as individual cells, again in contrast to epithelial cells. While epithelial cells form the lining of body structures, fibroblasts and related connective tissues sculpt the "bulk" of an organism. The life span of a fibroblast, as measured in chick embryos, is 57 ± 3 days. [4]
Activation of the neurons causes a contraction and stiffening of the end parts of the muscle spindle muscle fibers. [ citation needed ] Fusimotor neurons are classified as static or dynamic according to the type of muscle fibers they innervate and their effects on the responses of the Ia and II sensory neurons innervating the central, non ...
Amyloids are formed of long unbranched fibers that are characterized by an extended β-sheet secondary structure in which individual β strands (β-strands) (coloured arrows in the adjacent figure) are arranged in an orientation perpendicular to the long axis of the fiber. Such a structure is known as cross-β structure.
The smallest contractile unit in the fiber is called the sarcomere which is a repeating unit within two Z bands. The sarcoplasm also contains glycogen which provides energy to the cell during heightened exercise, and myoglobin , the red pigment that stores oxygen until needed for muscular activity.