Facial Colliculus

	Facial Colliculus The facial colliculus is an elevated area located in the pontine tegmentum (dorsal pons), within the floor of the fourth ventricle (i.e. the rhomboid fossa). It is formed by fibres from the facial motor nucleus looping over the abducens nucleus. The facial colliculus is an essential landmark of the rhomboid fossa. Anatomy The facial colliculus occurs within the rhomboid fossa (i.e. the floor of the fourth ventricle) where it is placed lateral to its (midline) median sulcus. Structure The facial colliculus is formed by brachial motor nerve fibres of the facial nerve (CN VII) looping over the (ipsilateral) abducens nucleus, forming a bump upon the surface. Clinical significance A facial colliculus lesion would result in ipsilateral facial paralysis (i.e. Bell's palsy Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Pontine Tegmentum Pontine may refer to: * Having to do with the pons, a structure located in the brain stem (from ''pons'', "bridge") * Pontine Marshes, a region of Italy near Rome * Pontine Islands The Pontine Islands (, also ; it, Isole Ponziane ) are an archipelago in the Tyrrhenian Sea off the coast of Lazio region, Italy. The islands were collectively named after the largest island in the group, Ponza. The other islands in the archipe ..., islands of Italy near Circeo See also {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Fourth Ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct (''aqueduct of Sylvius'') to the obex, and is filled with cerebrospinal fluid (CSF). The fourth ventricle has a characteristic diamond shape in cross-sections of the human brain. It is located within the pons or in the upper part of the medulla oblongata. CSF entering the fourth ventricle through the cerebral aqueduct can exit to the subarachnoid space of the spinal cord through two lateral apertures and a single, midline median aperture. Boundaries The fourth ventricle has a roof at its ''upper'' (posterior) surface and a floor at its ''lower'' (anterior) surface, and side walls formed by the cerebellar peduncles (nerve bundles joining the structure on the posterior sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Rhomboid Fossa The rhomboid fossa is a rhombus-shaped depression that is the anterior part of the fourth ventricle. Its anterior wall, formed by the back of the pons and the medulla oblongata, constitutes the floor of the fourth ventricle. It is covered by a thin layer of grey matter continuous with that of the spinal cord; superficial to this is a thin lamina of neuroglia which constitutes the ependyma of the ventricle and supports a layer of ciliated epithelium. Parts The fossa consists of three parts, superior, intermediate, and inferior: ;The superior part :The superior part is triangular in shape and limited laterally by the superior cerebellar peduncle; its apex, directed upward, is continuous with the cerebral aqueduct; its base is represented by an imaginary line at the level of the upper ends of the superior foveae. ;The intermediate part :The intermediate part extends from this level to that of the horizontal portions of the taeniae of the ventricle; it is narrow above where it is li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Facial Motor Nucleus The facial motor nucleus is a collection of neurons in the brainstem that belong to the facial nerve ( cranial nerve VII). These lower motor neurons innervate the muscles of facial expression and the stapedius. Structure The nucleus is situated in the caudal portion of the ventrolateral pontine tegmentum. Its axons take an unusual course, traveling dorsally and looping around the abducens nucleus, then traveling ventrally to exit the ventral pons medial to the spinal trigeminal nucleus. These axons form the motor component of the facial nerve, with parasympathetic and sensory components forming the intermediate nerve. The nucleus has a dorsal and ventral region, with neurons in the dorsal region innervating muscles of the upper face and neurons in the ventral region innervating muscles of the lower face. Function Because it innervates muscles derived from pharyngeal arches, the facial motor nucleus is considered part of the special visceral efferent (SVE) cell column, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Abducens Nucleus The abducens nucleus is the originating nucleus from which the abducens nerve (VI) emerges—a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the Anatomical terms of location, caudal portion of the pons, Anatomical terms of location, medial to the sulcus limitans. The abducens nucleus along with the internal genu of the facial nerve make up the facial colliculus, a hump at the caudal end of the medial eminence on the dorsal aspect of the pons. Structure Two primary neuron types are located in the abducens nucleus: motorneurons and interneurons. The former directly drive the contraction of the ipsilateral lateral rectus muscle via the abducens nerve (sixth cranial nerve); contraction of this muscle rotates the eye outward (abduction). The latter relay signals from the abducens nucleus to the contralateral oculomotor nucleus, where motoneurons drive the contraction of the ipsilateral medial rectus muscle (hence, contralateral to the abducens nucleus th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Facial Nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII (vestibulocochlear nerve). The facial nerve also supplies preganglionic parasympathetic fibers to several head and neck ganglia. The facial and intermediate nerves can be collectively referred to as the nervus intermediofacialis. The path of the facial nerve can be divided into six segments: # intracranial (cisternal) segment # meatal (canalicular) segment (within the internal auditory canal) # labyrinthine segment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 people have been diagnosed with some form of permanent or transient paralysis. The word "paralysis" derives from the Greek παράλυσις, meaning "disabling of the nerves" from παρά (''para'') meaning "beside, by" and λύσις (''lysis'') meaning "making loose". A paralysis accompanied by involuntary tremors is usually called "palsy". Causes Paralysis is most often caused by damage in the nervous system, especially the spinal cord. Other major causes are stroke, trauma with nerve injury, poliomyelitis, cerebral palsy, peripheral neuropathy, Parkinson's disease, ALS, botulism, spina bifida, multiple sclerosis, and Guillain–Barré syndrome. Temporary paralysis occurs during REM sleep, and dysregulation of this system can lead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Bell's Palsy Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary from mild to severe. They may include muscle twitching, weakness, or total loss of the ability to move one or, in rare cases, both sides of the face. Other symptoms include drooping of the eyelid, a change in taste, and pain around the ear. Typically symptoms come on over 48 hours. Bell's palsy can trigger an increased sensitivity to sound known as hyperacusis. The cause of Bell's palsy is unknown and it can occur in any age. Risk factors include diabetes, a recent upper respiratory tract infection, and pregnancy. It results from a dysfunction of cranial nerve VII (the facial nerve). Many believe that this is due to a viral infection that results in swelling. Diagnosis is based on a person's appearance and ruling out other possible causes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]