Search results
Results From The WOW.Com Content Network
However, the trigeminal lemniscus also carries pain and temperature sensations from the contralateral orofacial region, just as the spinothalamic tract carries these sensations from the contralateral body. Thus, the trigeminal lemniscus of the head is functionally analogous to both the DCML tracts and the spinothalamic tract of the body.
The only exceptions to this rule are certain spinal-cord lesions and the medullary syndromes, of which Wallenberg syndrome is the best-known example. In this syndrome, a stroke causes a loss of pain-temperature sensation from one side of the face and the other side of the body. This is explained by the anatomy of the brainstem.
Light from a single point of a distant object and light from a single point of a near object being brought to a focus. The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near object, then looking at a distant object (and vice versa), comprising coordinated changes in vergence, lens shape (accommodation) and pupil size.
Descending pathways also activate opioid receptor-containing parts of the spinal cord. [citation needed] Afferent pathways interfere with each other constructively, so that the brain can control the degree of pain that is perceived, based on which pain stimuli are to be ignored to pursue potential gains.
The ophthalmic nerve (CN V 1) is a sensory nerve of the head.It is one of three divisions of the trigeminal nerve (CN V), a cranial nerve.It has three major branches which provide sensory innervation to the eye, and the skin of the upper face and anterior scalp, as well as other structures of the head.
Horizontal gaze palsies can be caused by a lesion affecting any structure in these pathways. Lesions to abducens nucleus or PPRF typically create an ipsilateral gaze palsy, while lesions to MLF typically cause Internuclear ophthalmoplegia , a type of horizontal gaze palsy in which the affected eye cannot adduct in conjugation with the ...
Descartes' pain pathway: "Particles of heat" (A) activate a spot of skin (B) attached by a fine thread (cc) to a valve in the brain (de) where this activity opens the valve, allowing the animal spirits to flow from a cavity (F) into the muscles causing them to flinch from the stimulus, turn the head and eyes toward the affected body part, and ...
This may be due to chronic pain, [2] or during dental or surgical procedures of the face such as for the management of postoperative pain associated with cleft lip correction. [ 4 ] The needle is inserted (aiming medially) near to the infraorbital foramen , which can be palpated . [ 2 ]