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Autonomic Nerve
The autonomic nerve is a small nerve which carries postganglionic sympathetic and parasympathetic neurons from the zygomaticotemporal nerve; a branch of the maxillary nerve, to the lacrimal nerve; a branch of the ophthalmic nerve. These neurons derive from the superior cervical ganglion and the pterygopalatine ganglion respectively. They will travel to the lacrimal gland The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each or ... via the lacrimal nerve. Parasympathetic will induce lacrimation and vice versa. References Nerves {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postganglionic Nerve Fibers
In the autonomic nervous system, fibers from the ganglion to the effector organ are called postganglionic fibers. Neurotransmitters The neurotransmitters of postganglionic fibers differ: * In the parasympathetic division, neurons are ''cholinergic''. That is to say acetylcholine is the primary neurotransmitter responsible for the communication between neurons on the parasympathetic pathway. * In the sympathetic division, neurons are mostly ''adrenergic'' (that is, epinephrine and norepinephrine function as the primary neurotransmitters). Notable exceptions to this rule include the sympathetic innervation of sweat glands and arrectores pilorum muscles where the neurotransmitter at both pre and post ganglionic synapses is acetylcholine. Another notable structure is the medulla of the adrenal gland, where chromaffin cells function as modified post-ganglionic nerves. Instead of releasing epinephrine and norepinephrine into a synaptic cleft, these cells of the adrenal medulla rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic Nervous System
The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system. The autonomic nervous system functions to regulate the body's unconscious actions. The sympathetic nervous system's primary process is to stimulate the body's fight or flight response. It is, however, constantly active at a basic level to maintain homeostasis. The sympathetic nervous system is described as being antagonistic to the parasympathetic nervous system which stimulates the body to "feed and breed" and to (then) "rest-and-digest". Structure There are two kinds of neurons involved in the transmission of any signal through the sympathetic system: pre-ganglionic and post-ganglionic. The shorter preganglionic neurons originate in the thoracolumbar division o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasympathetic Nervous 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 enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygomaticotemporal Nerve
The zygomaticotemporal nerve (zygomaticotemporal branch, temporal branch) is a small nerve of the face. It is derived from the zygomatic nerve, a branch of the maxillary nerve (CN V2). It is distributed to the skin of the side of the forehead. It communicates with the facial nerve and with the auriculotemporal branch of the mandibular nerve. Structure The zygomaticotemporal nerve is a branch of the zygomatic nerve, a branch of the maxillary nerve. It runs along the lateral wall of the orbit in a groove in the zygomatic bone, receives a branch of communication from the lacrimal nerve, and passes through the zygomaticotemporal foramen in the zygomatic bone to enter the temporal fossa. It ascends between the bone and the substance of the temporalis muscle. It pierces the temporal fascia about 2.5 cm above the zygomatic arch. This is around 17 mm lateral to and 6.5 mm superior to the lateral palpebral fissure. It is distributed to the skin of the side of the forehead. The zygo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary Nerve
In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate and subsequently that of the mid-face, and is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 180 Structure It begins at the middle of the trigeminal ganglion as a flattened plexiform band then it passes through the lateral wall of the cavernous sinus. It leaves the skull through the foramen rotundum, where it becomes more cylindrical in form, and firmer in texture. After leaving foramen rotundum it gives two branches to the pterygopalatine ganglion. It then crosses the pterygopalatine fossa, inclines lateralward on the back of the maxilla, and enters the orbit through the inferior orbital fissure. It then r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Nerve
The lacrimal nerve is the smallest branch of the ophthalmic nerve (V1), itself a branch of the trigeminal nerve (CN V). The other branches of the ophthalmic nerve are the frontal nerve and nasociliary nerve. Structure The lacrimal nerve branches from the ophthalmic nerve immediately before traveling through the superior orbital fissure to enter the orbit. It travels through it lateral to the frontal nerve outside the annulus of Zinn. After entering, it travels anteriorly along the lateral wall with the lacrimal artery, above the upper margin of the lateral rectus. It receives a communicating branch from the zygomatic nerve which carries the postganglionic parasympathetic axons from the pterygopalatine ganglion. It travels through the lacrimal gland giving sensory and parasympathetic branches to it and then continues anteriorly as a few small sensory branches. Function The lacrimal nerve provides sensory innervation to the lacrimal gland, conjunctiva of the lateral upper eyeli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmic Nerve
The ophthalmic nerve (V1) is a sensory nerve of the face. It is one of three divisions of the trigeminal nerve (CN V). It has three branches that provide sensory innervation to the eye, the skin of the upper face, and the skin of the anterior scalp. Structure The ophthalmic nerve is the first branch of the trigeminal nerve (CN V). It is joined by filaments from the cavernous plexus of the sympathetic, and communicates with the oculomotor, trochlear, and abducent nerves. It gives off a recurrent (meningeal) filament which passes between the layers of the tentorium. Branches The ophthalmic nerve divides into three major branches as it passes through the superior orbital fissure. *The nasociliary nerve gives off several sensory branches to the orbit. It then continues out through the anterior ethmoidal foramen, where it enters the nasal cavity. It provides innervation for much of the anterior nasal mucosa. It also gives off a branch which exits through the nasal bones to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Cervical Ganglion
The superior cervical ganglion (SCG) is part of the autonomic nervous system (ANS); more specifically, it is part of the sympathetic nervous system, a division of the ANS most commonly associated with the fight or flight response. The ANS is composed of pathways that lead to and from ganglia, groups of nerve cells. A ganglion allows a large amount of divergence in a neuronal pathway and also enables a more localized circuitry for control of the innervated targets. The SCG is the only ganglion in the sympathetic nervous system that innervates the head and neck. It is the largest and most rostral (superior) of the three cervical ganglia. The SCG innervates many organs, glands and parts of the carotid system in the head. Structure Location The SCG is located opposite the second and third cervical vertebrae. It lies deep to the sheath of the internal carotid artery and internal jugular vein, and anterior to the Longus capitis muscle. The SCG contains neurons that supply sympathetic ... [...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 found in the pterygopalatine fossa. It is largely innervated by the greater petrosal nerve (a branch of the facial nerve); and its postsinaptic 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. It is one of four parasympathetic ganglia of the head and neck, the others being the submandibular ganglion, otic ganglion, and ciliary ganglion. 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, of a reddish-gray color, and is situated just below the maxillary nerve as it cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Gland
The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called dacryoadenitis. The lacrimal gland produces tears which are secreted by the lacrimal ducts, and flow over the ocular surface, and then into canals that connect to the lacrimal sac. From that sac, the tears drain through the lacrimal duct into the nose. Anatomists divide the gland into two sections, a palpebral lobe, or portion, and an orbital lobe or portion. The smaller ''palpebral lobe'' lies close to the eye, along the inner surface of the eyelid; if the upper eyelid is everted, the palpebral portion can be seen. The orbital lobe of the gland, contains fine interlobular ducts that connect the orbital lobe and the palpebra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
