von Ebner Glands
Parasympathetic Fibers, Postganglionic
Ionotropic glutamate receptor expression in preganglionic neurons of the rat inferior salivatory nucleus. (1/2)
Glutamate receptor (GluR) subunit composition of inferior salivatory nucleus (ISN) neurons was studied by immunohistochemical staining of retrogradely labeled neurons. Preganglionic ISN neurons innervating the von Ebner or parotid salivary glands were labeled by application of a fluorescent tracer to the lingual-tonsilar branch of the glossopharyngeal nerve or the otic ganglion respectively. We used polyclonal antibodies to glutamate receptor subunits NR1, NR2A, NR2B, (NMDA receptor subunits) GluR1, GluR2, GluR3, GluR4 (AMPA receptor subunits), and GluR5-7, KA2 (kainate receptor subunits) to determine their expression in ISN neurons. The distribution of the NMDA, AMPA and kainate receptor subunits in retrogradely labeled ISN neurons innervating the von Ebner and parotid glands was qualitatively similar. The percentage of retrogradley labeled ISN neurons innervating the parotid gland expressing the GluR subunits was always greater than those innervating the von Ebner gland. For both von Ebner and parotid ISN neurons, NR2A subunit staining had the highest expression and the lowest expression of GluR subunit staining was NR2B for von Ebner ISN neurons and GluR1 for parotid ISN neurons. The percentage of NR2B and GluR4 expressing ISN neurons was significantly different between the two glands. The percentage of ISN neurons that expressed GluR receptor subunits ranged widely indicating that the distribution of GluR subunit expression differs amongst the ISN neurons. While ISN preganglionic neurons express all the GluR subunits, differences in the percentage of ISN neurons expression between neurons innervating the von Ebner and parotid glands may relate to the different functional roles of these glands. (+info)Necessity of the glossopharyngeal nerve in the maintenance of normal intake and ingestive bout size of corn oil by rats. (2/2)
(+info)Von Ebner glands, also known as serous glands of von Ebner or striated ducts of von Ebner, are specialized exocrine glands located in the tongue. They are found in the deep surface of the circumvallate papillae and some other taste papillae on the dorsal surface of the tongue. These glands secrete serous fluid that helps to clean and lubricate the taste buds, as well as to wash away tastant molecules, enabling the tongue to continuously taste new stimuli. The fluid secreted by von Ebner glands also contains enzymes that help in digestion, such as lingual lipase. These glands are named after the German anatomist Victor von Ebner (1842-1925), who first described them in 1873.
Parasympathetic fibers, postganglionic, refer to the portion of the parasympathetic nervous system's peripheral nerves that arise from ganglia (clusters of neurons) located near or within the target organs. These postganglionic fibers are responsible for transmitting signals from the ganglia to the effector organs such as glands, smooth muscles, and heart, instructing them to carry out specific functions.
The parasympathetic nervous system is one of the two subdivisions of the autonomic nervous system (the other being the sympathetic nervous system). Its primary role is to conserve energy and maintain homeostasis during rest or digestion. The preganglionic fibers originate in the brainstem and sacral spinal cord, synapsing in the ganglia located near or within the target organs. Upon receiving signals from the preganglionic fibers, the postganglionic fibers release neurotransmitters like acetylcholine to activate muscarinic receptors on the effector organ, leading to responses such as decreased heart rate, increased gastrointestinal motility and secretion, and contraction of the urinary bladder.
The sublingual glands are a pair of salivary glands located in the floor of the mouth, beneath the tongue. They are the smallest of the major salivary glands and produce around 5-10% of the total saliva in the mouth. The sublingual glands secrete saliva containing electrolytes, enzymes (such as amylase), and antibacterial compounds that help in digestion, lubrication, and protection against microorganisms.
The sublingual glands' secretions are released through multiple small ducts called the ducts of Rivinus or minor sublingual ducts, as well as a larger duct called the duct of Wharton, which is a common excretory duct for both sublingual and submandibular glands.
Sublingual gland dysfunction can lead to conditions such as dry mouth (xerostomia), dental caries, or oral infections.
The parotid gland is the largest of the major salivary glands. It is a bilobed, accessory digestive organ that secretes serous saliva into the mouth via the parotid duct (Stensen's duct), located near the upper second molar tooth. The parotid gland is primarily responsible for moistening and lubricating food to aid in swallowing and digestion.
Anatomically, the parotid gland is located in the preauricular region, extending from the zygomatic arch superiorly to the angle of the mandible inferiorly, and from the masseter muscle anteriorly to the sternocleidomastoid muscle posteriorly. It is enclosed within a fascial capsule and has a rich blood supply from the external carotid artery and a complex innervation pattern involving both parasympathetic and sympathetic fibers.
Parotid gland disorders can include salivary gland stones (sialolithiasis), infections, inflammatory conditions, benign or malignant tumors, and autoimmune diseases such as Sjögren's syndrome.