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Nucleus Ambiguus
The nucleus ambiguus ("ambiguous nucleus" in English) is a group of large motor neurons, situated deep in the medullary part of the reticular formation named by Jacob Clarke. The nucleus ambiguus contains the cell bodies of neurons that innervate the muscles of the soft palate, pharynx, and larynx which are associated with speech and swallowing. As well as motor neurons, the nucleus ambiguus contains preganglionic parasympathetic neurons which innervate postganglionic parasympathetic neurons in the heart.Machado, BH and Brody, MJ"Role MJ of the nucleus ambiguus in the regulation of heart rate and arterial pressure."/ref> It is a region of histologically disparate cells located just dorsal ( posterior) to the inferior olivary nucleus in the lateral portion of the upper (rostral) medulla. It receives upper motor neuron innervation directly via the corticobulbar tract. This nucleus gives rise to the branchial efferent motor fibers of the vagus nerve (CN X) terminating in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Plane
A transverse plane is a plane that is rotated 90° from two other planes. Anatomy The transverse plane is an anatomical plane that is perpendicular to the sagittal plane and the dorsal plane. It is also called the axial plane or horizontal plane, especially in human anatomy, but horizontal plane can be misleading with other animals. The plane splits the body into a cranial (head) side and caudal (tail) side, so in humans the plane will be horizontal (dividing the body into superior and inferior sections) but in quadrupeds it will be vertical. Human anatomy Clinically relevant anatomical planes * Transverse '' thoracic plane'' * '' Xiphosternal plane'' (or xiphosternal junction) * '' Transpyloric plane'' * '' Subcostal plane'' * '' Umbilical plane'' (or transumbilical plane) * '' Supracristal plane'' * '' Intertubercular plane'' (or transtubercular plane) * '' Interspinous plane'' Associated structures * The transverse '' thoracic plane'' ** Plane through T4 & T5 verteb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solitary Tract
The solitary tract (tractus solitarius or fasciculus solitarius) is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla oblongata. The solitary tract is surrounded by the solitary nucleus, and descends to the upper cervical segments of the spinal cord. It was first named by Theodor Meynert in 1872. Composition The solitary tract is made up of primary sensory fibers and descending fibers of the vagus, glossopharyngeal, and facial nerves. Function The solitary tract conveys afferent information from stretch receptors and chemoreceptors in the walls of the cardiovascular, respiratory, and intestinal tracts. Afferent fibers from cranial nerves 7, 9 and 10 convey taste ( SVA) in its rostral portion, and general visceral sense ( general visceral afferent fibers, GVA) in its caudal part. Taste buds in the mucosa of the tongue can also generate impulses in the rostral Rostral may refer to: Anatomy * Rostral (anatomical term), situ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Levator Veli Palatini
The levator veli palatini () is a muscle of the soft palate and pharynx. It is innervated by the vagus nerve (cranial nerve X) via its pharyngeal plexus. During swallowing, it contracts, elevating the soft palate to help prevent food from entering the nasopharynx. Structure The levator veli palatini muscle occurs in the soft palate of the mouth. It forms a sling superior and immediately posterior to the palatine aponeurosis. Origin The primary site of origin of the muscle is a quadrangular roughened area upon the medial extremity of the inferior aspect of the petrous part of the temporal bone; here, the muscle arises by a small tendon. Additional fibres of the muscle arise from the inferior aspect of the cartilaginous part of pharyngotympanic tube, and the vaginal process of sphenoid bone. Insertion In the medial third of the soft palate, its fibers spread out between the two strands of the palatoglossus muscle to attach to the superior surface of the palatine aponeur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranial Root Of Accessory Nerves
The cranial root of accessory nerve (or part) is the smaller of the two portions of the accessory nerve. It is generally considered as a part of the vagus nerve and not part of the accessory nerve proper because the cranial component rapidly joins the vagus nerve and serves the same function as other vagal nerve fibers. Recently, the concept of a cranial root of the accessory nerve has been challenged by new neuroanatomical studies which found that an unambiguous cranial root was not present in the majority of the cases. However, a small study in 2007 followed by a substantially larger study published in 2012Cranial roots of the accessory nerve exist in the majority of adult humans. Tubbs RS, Benninger B, Loukas M, Cohen-Gadol AA 2012 Clin Anat. doi: 10.1002/ca.22125 both confirmed that the cranial root of the accessory nerve is commonly found in humans, matching traditional descriptions. Path The cranial root fibers arise from the cells of the nucleus ambiguus and emerge as four o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uvula
The uvula (: uvulas or uvulae), also known as the palatine uvula or staphyle, is a conic projection from the back edge of the middle of the soft palate, composed of connective tissue containing a number of racemose glands, and some muscular fibers. It also contains many serous glands, which produce thin saliva. It is only found in humans. Structure Muscle The muscular part of the uvula () shortens and broadens the uvula. This changes the contour of the posterior part of the soft palate. This change in contour allows the soft palate to adapt closely to the posterior pharyngeal wall to help close the nasopharynx during swallowing. Its muscles are controlled by the pharyngeal branch of the vagus nerve. Variation A bifid or bifurcated uvula is a split or cleft uvula. Newborns with cleft palate often also have a split uvula. The bifid uvula results from incomplete fusion of the palatine shelves but it is considered only a slight form of clefting. Bifid uvulas have les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysphonia
A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice can be associated with a feeling of unease or scratchiness in the throat. Hoarseness is often a symptom of problems in the vocal folds of the larynx. It may be caused by laryngitis, which in turn may be caused by an upper respiratory infection, a cold, or allergies. Cheering at sporting events, speaking loudly in noisy environments, talking for too long without resting one's voice, singing loudly, or speaking with a voice that is too high or too low can also cause temporary hoarseness. A number of other causes for losing one's voice exist, and treatment is generally by resting the voice and treating the underlying cause. If the cause is misuse or overuse of the voice, drinking plenty of water may alleviate the problems. It appears to occur more commonly in females and the elderly. Furthermore, certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysphagia
Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or liquids from the mouth to the stomach, a lack of pharyngeal sensation or various other inadequacies of the swallowing mechanism. Dysphagia is distinguished from other symptoms including odynophagia, which is defined as painful swallowing, and globus, which is the sensation of a lump in the throat. A person can have dysphagia without odynophagia (dysfunction without pain), odynophagia without dysphagia (pain without dysfunction) or both together. A psychogenic dysphagia is known as phagophobia. Classification Dysphagia is classified into the following major types: # Oropharyngeal dysphagia # Esophageal and obstructive dysphagia # Neuromuscular symptom complexes # Functional dysphagia is defined in some patients as having no organic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stylopharyngeus
The stylopharyngeus muscle is a muscle in the head. It originates from the temporal styloid process. Some of its fibres insert onto the thyroid cartilage, while others end by intermingling with proximal structures. It is innervated by the glossopharyngeal nerve (cranial nerve IX). It acts to elevate the larynx and pharynx, and dilate the pharynx, thus facilitating swallowing. Structure The stylopharyngeus is a long, slender, tapered pharyngeal muscle. It is cylindrical superiorly, and flattened inferiorly. It passes inferior-ward along the side of the pharynx between the superior pharyngeal constrictor (situated deep to the stylopharyngeus) and the middle pharyngeal constrictor (situated superficial to the stylopharyngeus), before spreads out beneath the mucous membrane. Origin It arises from (the medial side of the base of) the temporal styloid process. It is the only muscle of the pharynx not to originate in the pharyngeal wall. Insertion Some of its fibers are lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossopharyngeal Nerve
The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper Medulla oblongata, medulla, just anterior (closer to the nose) to the vagus nerve. Being a mixed nerve (sensorimotor), it carries afferent sensory and efferent motor information. The motor division of the glossopharyngeal nerve is derived from the Basal plate (neural tube), basal plate of the embryonic medulla oblongata, whereas the sensory division originates from the cranial neural crest. Structure From the anterior portion of the medulla oblongata, the glossopharyngeal nerve passes laterally across or below the Flocculus (cerebellar), flocculus, and leaves the skull through the central part of the jugular foramen. From the superior and inferior ganglia in jugular foramen, it has its own sheath of dura mater. The inferior ganglion on the inferior surface of petrous part of temporal is related with a tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musculus Uvulae
The musculus uvulae (also muscle of uvula, uvular muscle, or palatouvularis muscle) is a bilaterally muscle of the soft palate (one of five such muscles) that acts to shorten the uvula when both muscles contract. It forms most of the mass of the uvula. It is innervated by the pharyngeal plexus of vagus nerve (cranial nerve X). Anatomy The muscle is situated in between the two laminae of the palatine aponeurosis. From its origin, it passes posterior-ward superior to the swing that is formed by the levator veli palatini muscle. The musculus uvulae and levator veli palatini muscle form a right angle so that their contraction elevates the levator eminence to aid in separating the oral cavity and the oropharynx. Origin The muscle arises from the posterior nasal spine of the palatine bone, and the (superior aspect of the) palatine aponeurosis. Insertion The muscle inserts into the mucous membrane of the uvula. Vasculature The muscle receives arterial blood from the asce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagus Nerve
The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibers and serves as a major pathway that connects the brain to various organs, including the heart, lungs, and digestive tract. As a key part of the parasympathetic nervous system, the vagus nerve helps regulate essential involuntary functions like heart rate, breathing, and digestion. By controlling these processes, the vagus nerve contributes to the body's "rest and digest" response, helping to calm the body after stress, lower heart rate, improve digestion, and maintain homeostasis. The vagus nerve consists of two branches: the right and left vagus nerves. In the neck, the right vagus nerve contains approximately 105,000 fibers, while the left vagus nerve has about 87,000 fibers, according to one source. However, other sources report sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
