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Cranial Ganglia
In neuroanatomy, the cranial nerve ganglia are ganglia of certain cranial nerves. They can be parasympathetic or sensory. All cranial nerve ganglia are bilateral. Parasympathetic The four cranial parasympathetic ganglia are: * ciliary ganglion * pterygopalatine ganglion * otic ganglion * submandibular ganglion Sensory * trigeminal ganglion (CN V) * geniculate ganglion (CN VII) * spiral ganglion (CN VIII) * vestibular ganglion aka Scarpa's ganglion (CN VIII) * superior ganglion of glossopharyngeal nerve * inferior ganglion of glossopharyngeal nerve The inferior ganglion of the glossopharyngeal nerve (petrosal ganglion) is a sensory ganglion. It is larger than and inferior to the superior ganglion of the glossopharyngeal nerve. It is located within the jugular foramen. The pseudounipolar ne ... * superior ganglion of vagus nerve * inferior ganglion of vagus nerve References Nervous ganglia {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroanatomy
Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defined nervous systems. Their neuroanatomy is therefore better understood. In vertebrates, the nervous system is segregated into the internal structure of the brain and spinal cord (together called the central nervous system, or CNS) and the series of nerves that connect the CNS to the rest of the body (known as the peripheral nervous system, or PNS). Breaking down and identifying specific parts of the nervous system has been crucial for figuring out how it operates. For example, much of what neuroscientists have learned comes from observing how damage or "lesions" to specific brain areas affects behavior or other neural functions. For information about the composition of non-human animal nervous systems, see nervous system. For information a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglia
A ganglion (: ganglia) is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system, this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system, there are both sympathetic and parasympathetic ganglia which contain the cell bodies of postganglionic sympathetic and parasympathetic neurons respectively. A pseudoganglion looks like a ganglion, but only has nerve fibers and has no nerve cell bodies. Structure Ganglia are primarily made up of somata and dendritic structures, which are bundled or connected. Ganglia often interconnect with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems. Among vertebrates there are three major groups of ganglia: * Dorsal root ganglia (also known as the spinal ganglia) cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranial Nerves
Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and from regions of the head and neck, including the special senses of Visual perception, vision, taste, Olfaction, smell, and hearing. The cranial nerves emerge from the central nervous system above the level of the Atlas (anatomy), first vertebra of the vertebral column. Each cranial nerve is paired and is present on both sides. There are conventionally twelve pairs of cranial nerves, which are described with Roman numerals I–XII. Some considered there to be thirteen pairs of cranial nerves, including the non-paired cranial nerve zero. The numbering of the cranial nerves is based on the order in which they emerge from the brain and brainstem, from front to back. The terminal nerves (0), olfactory nerves (I) and optic nerves (II) emerge f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasympathetic System
The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed-and-breed" activities that occur when the body is at rest, especially after eating, including sexual arousal, salivation, lacrimation (tears), urination, digestion, and defecation. Its action is described as being complementary to that of the sympathetic nervous system, which is responsible for stimulating activities associated with the fight-or-flight response. Nerve fibres of the parasympathetic nervous system arise from the central nervous system. Specific nerves include several cranial nerves, specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve, and vagus nerve. Three spinal nerves in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliary Ganglion
The ciliary ganglion is a parasympathetic ganglion located just behind the eye in the posterior orbit. It is 1–2 mm in diameter and in humans contains approximately 2,500 neurons. The ganglion contains postganglionic parasympathetic neurons. These neurons supply the pupillary sphincter muscle, which constricts the pupil, and the ciliary muscle which contracts to make the lens more convex. Both of these muscles are involuntary since they are controlled by the parasympathetic division of the autonomic nervous system. The ciliary ganglion is one of four parasympathetic ganglia of the head. The others are the submandibular ganglion, pterygopalatine ganglion, and otic ganglion. Structure The ciliary ganglion contains postganglionic parasympathetic neurons that supply the ciliary muscle and the pupillary sphincter muscle. Because of the much larger size of the ciliary muscle, 95% of the neurons in the ciliary ganglion innervate it compared to the pupillary sphincter. Roots T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterygopalatine Ganglion
The pterygopalatine ganglion (aka Meckel's ganglion, nasal ganglion, or sphenopalatine ganglion) is a parasympathetic ganglion in the pterygopalatine fossa. It is one of four parasympathetic ganglia of the head and neck, (the others being the submandibular, otic, and ciliary ganglion). It is innervated by the Vidian nerve (formed by the greater superficial petrosal nerve branch of the facial nerve and deep petrosal nerve) and maxillary division of the trigeminal nerve. Its postsynaptic axons project to the lacrimal glands and nasal mucosa. The flow of blood to the nasal mucosa, in particular the venous plexus of the conchae, is regulated by the pterygopalatine ganglion and heats or cools the air in the nose. Structure The pterygopalatine ganglion (of Meckel), the largest of the parasympathetic ganglia associated with the branches of the maxillary nerve, is deeply placed in the pterygopalatine fossa, close to the sphenopalatine foramen. It is triangular or heart-shaped ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otic Ganglion
The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopharyngeal nerve and innervates the parotid gland for salivation. It is one of four parasympathetic ganglia of the head and neck. The others are the ciliary ganglion, the submandibular ganglion and the pterygopalatine ganglion. Structure and relations The otic ganglion is a small (2–3 mm), oval shaped, flattened parasympathetic ganglion of a reddish-grey color, located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is in relation, laterally, with the trunk of the mandibular nerve at the point where the motor and sensory roots join; medially, with the cartilaginous part of the auditory tube, and the origin of the tensor veli palatini; posteriorly, with the middle meningeal artery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submandibular Ganglion
The submandibular ganglion (or submaxillary ganglion in older texts) is part of the human autonomic nervous system. It is one of four parasympathetic ganglia of the head and neck. (The others are the otic ganglion, pterygopalatine ganglion, and ciliary ganglion). Location and relations The submandibular ganglion is small and fusiform in shape. It is situated above the deep portion of the submandibular gland, on the hyoglossus muscle, near the posterior border of the mylohyoid muscle. The ganglion 'hangs' by two nerve filaments from the lower border of the lingual nerve (itself a branch of the mandibular nerve, CN V3). It is suspended from the lingual nerve by two filaments, one anterior and one posterior. Through the posterior of these it receives a branch from the chorda tympani nerve which runs in the sheath of the lingual nerve. Fibers Like other parasympathetic ganglia of the head and neck, the submandibular ganglion is the site of synapse for parasympathetic fibers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigeminal Ganglion
The trigeminal ganglion (also known as: Gasserian ganglion, semilunar ganglion, or Gasser's ganglion) is the sensory ganglion of each trigeminal nerve (CN V). The trigeminal ganglion is located within the trigeminal cave (Meckel's cave), a cavity formed by dura mater. Anatomy The trigeminal ganglion contains cell bodies of the pseudo-unipolar sensory neurons of the trigeminal nerve which extend their axons both distally/peripherally into the three divisions of the trigeminal nerve on the one end, and proximally/centrally to the brainstem on the other end; the trigeminal root extends from the trigeminal ganglion to the ventrolateral aspect of the pons. The trigeminal ganglion is situated within the trigeminal cave (or Meckel's cave), a cerebrospinal fluid-filled cavity formed by a double layer of dura mater overlying the trigeminal impression near the apex of the petrous part of the temporal bone. Structure The trigeminal ganglion is somewhat crescent-shaped, with its co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geniculate Ganglion
The geniculate ganglion (from Latin ''genu'', for "knee") is a bilaterally paired special sense ganglion of the intermediate nerve component of the facial nerve (CN VII). It is situated within facial canal of the head. It contains cell bodies of first-order unipolar sensory neurons which convey gustatory (taste) afferents from taste receptors of the anterior two-thirds of the tongue by way of the chorda tympani, and of the palate by way of the greater petrosal nerve, From the ganglion, the proximal fibres proceed to the gustatory (i.e. superior/rostral) part of the solitary nucleus where they synapse with second-order neurons. Anatomy Structure The geniculate ganglion is conical in shape. The greater petrosal nerve diverges from CNVII and the lesser petrosal nerve diverges from CN IX at the geniculate ganglion. Relations It is located close to the internal auditory meatus. It is covered superiorly by the petrous part of the temporal bone (which is sometimes abse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Ganglion
The spiral (cochlear) ganglion is a group of neuron cell bodies in the modiolus, the conical central axis of the cochlea. These bipolar neurons innervate the hair cells of the organ of Corti. They project their axons to the ventral and dorsal cochlear nuclei as the cochlear nerve, a branch of the vestibulocochlear nerve (CN VIII). Structure Neurons whose cell bodies lie in the spiral ganglion are strung along the bony core of the cochlea, and send fibers (axons) into the central nervous system (CNS). These bipolar neurons are the first neurons in the auditory system to fire an action potential, and supply all of the brain's auditory input. Their dendrites make synaptic contact with the base of hair cells, and their axons are bundled together to form the auditory portion of eighth cranial nerve. The number of neurons in the spiral ganglion is estimated to be about 35,000–50,000. Two apparent subtypes of spiral ganglion cells exist. Type I spiral ganglion cells com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibular Ganglion Aka Scarpa's Ganglion
The Vestibular (from , "entrance hall") is a competitive examination and is the primary and widespread entrance system used by Brazilian universities to select the students admitted. The Vestibular usually takes place from November to January, right before the start of school year in February or March, although certain universities hold it every semester. The exams often span several days, usually two, with different disciplines being tested each day. Structure Several Brazilian universities follow the FUVEST (University of São Paulo's entry exam) pattern, which is divided into two stages or "phases". The first stage consists of 90 multiple choice questions, including subjects such as Portuguese Language, Portuguese Literature and Brazilian Literature; Math, History, Geography, Biology, Physics, Chemistry and Foreign Language. The answers are marked on an answer card, and they are graded afterwards by an automated optical reader. Some institutions establish a cutoff score ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
