The current model of descending pain modulation involves both inhibitory and facilitatory influences on spinal nociceptive transmission. The balance between inhibition and facilitation is dependent on different behavioral, emotional, and…
The thalamus is the main relay structure for sensory information destined for the cortex; it is involved in reception, integration, and transfer of nociceptive potentials. WDR neurons project to the…
Although initially the affected pupil is larger than the contralateral pupil, with time it can become smaller. The pupil is very sensitive to acetylcholine (probably due to denervation supersensitivity), with…
Autonomic disorders may be classified as peripheral or central and acute or chronic disorders. ACUTE PERIPHERAL AUTONOMIC DISORDERS Acute/subacute autonomic neuropathies are usually due to toxic, metabolic, autoimmune, or paraneoplastic…
C-type fibers (unmyelinated) slowly propagate dull, burning (secondary) pain sensation information. Some C fibers are modality-specific and respond only to thermal, mechanical, or chemical noxious stimuli. However, the majority of…
SWEAT TESTING The thermoregulatory sweat test consists of the visual detection of skin humidity in response to warm external temperature. A dye that changes color when moist is painted or…
An inferior group of a few small nerves arises from the inferior hypogastric plexus and from the nerve loops around the lower end of the ureter (see page 195). This…
Sympathetic preganglionic fibers are the axons of intermediolateral column cells located in the lowest two or three thoracic and upper one or two lumbar segments of the spinal cord. They…
Most of the nerve fasciculi in the urinary bladder wall contain unmyelinated or finely myelinated fibers. A small proportion of larger myelinated and, presumably, sensory fibers are connected with terminal…
Sympathetic Fibers. The lumbar and sacral parts of the sympathetic trunks are directly continuous at the level of the pelvic brim. The sacral trunks lie in the pelvic fascia behind…
