Which tract contains primary afferent neuron Fibres?
More than two-thirds of the axons in the tract of Lissauer at mid-thoracic and lumbosacral levels of the rat spinal cord are primary afferent fibers.
Which is characteristic of C fibers?
The C group fibers are unmyelinated and have a small diameter and low conduction velocity, whereas Groups A and B are myelinated. Group C fibers include postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots (IV fiber). These fibers carry sensory information.
What nerves are involved in micturition?
The pelvic nerves, which originate at the S2-S4 level sacral level of the spinal cord, are the main parasympathetic nerves and they ‘make you pee’, they cause contraction of the detrusor muscle and relaxation of the internal sphincter.
What are nerve fibers?
axon, also called nerve fibre, portion of a nerve cell (neuron) that carries nerve impulses away from the cell body. A neuron typically has one axon that connects it with other neurons or with muscle or gland cells. Some axons may be quite long, reaching, for example, from the spinal cord down to a toe.
What are AB and C fibers?
A-alpha nerve fibers carry information related to proprioception (muscle sense). A-beta nerve fibers carry information related to touch. A-delta nerve fibers carry information related to pain and temperature. C-nerve fibers carry information related to pain, temperature and itch.
What is an afferent nerve fiber?
a nerve fiber, typically a sensory fiber, that conducts impulses toward the brain or spinal cord or from a lower to a higher center of the central nervous system.
What are afferent nerve fibres?
Afferent nerve fibers are the axons (nerve fibers) carried by a sensory nerve that relay sensory information from sensory receptors to regions of the brain. Afferent projections arrive at a particular brain region. Efferent nerve fibers are carried by efferent nerves and exit a region to act on muscles and glands.
What is a nerve fiber?
What are A and C nerve fibers?
What type of reflex is micturition?
The micturition reflex is one of the autonomic reflexes, but the release of urine is regulated by voluntary neural mechanisms that involve centers in the brain and spinal cord.