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Preganglionic Neurons
A ganglion 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) contain the cell bodies of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrograph
A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a microscope but is only slightly magnified, usually less than 10 times. Micrography is the practice or art of using microscopes to make photographs. A micrograph contains extensive details of microstructure. A wealth of information can be obtained from a simple micrograph like behavior of the material under different conditions, the phases found in the system, failure analysis, grain size estimation, elemental analysis and so on. Micrographs are widely used in all fields of microscopy. Types Photomicrograph A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, a process referred to as ''photomicroscopy''. At a basic level, photomicroscopy may be performed simply by connecting a camera to a microscope, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autonomic Ganglion
An autonomic ganglion is a cluster of nerve cell bodies (a ganglion) in the autonomic nervous system The autonomic nervous system (ANS), formerly referred to as the vegetative nervous system, is a division of the peripheral nervous system that supplies viscera, internal organs, smooth muscle and glands. The autonomic nervous system is a control .... The two types are the sympathetic ganglion and the parasympathetic ganglion. References {{Authority control Autonomic nervous system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ganglion Cyst
A ganglion cyst is a fluid-filled bump associated with a joint or tendon sheath. It most often occurs at the back of the wrist, followed by the front of the wrist. Onset is often over several months, typically with no further symptoms. Occasionally, pain or numbness may occur. Complications may include carpal tunnel syndrome. The cause is unknown. The underlying mechanism is believed to involve an outpouching of the synovial membrane. Risk factors include gymnastics activity. Diagnosis is typically based on examination with light shining through the lesion being supportive. Medical imaging may be done to rule out other potential causes. Treatment options include watchful waiting, splinting the affected joint, needle aspiration, or surgery. About half the time, they resolve on their own. About three per 10,000 people newly develop ganglion of the wrist or hand a year. They most commonly occur in young and middle-aged females. Presentation The average size of these cysts is 2.0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Nerve
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin. It originates from the brachial plexus, carrying fibers from the ventral roots of spinal nerves C5, C6, C7, C8 & T1. The radial nerve and its branches provide motor innervation to the dorsal arm muscles (the triceps brachii and the anconeus) and the extrinsic extensors of the wrists and hands; it also provides cutaneous sensory innervation to most of the back of the hand, except for the back of the little finger and adjacent half of the ring finger (which are innervated by the ulnar nerve). The radial nerve divides into a deep branch, which becomes the posterior interosseous nerve, and a superficial branch, which goes on to innervate the dorsum (back) of the hand. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teres Minor Muscle
The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the greater tubercle of the humerus and the posterior surface of the joint capsule. The primary function of the teres minor is to modulate the action of the deltoid, preventing the humeral head from sliding upward as the arm is abducted. It also functions to rotate the humerus laterally. The teres minor is innervated by the axillary nerve. Structure It arises from the dorsal surface of the axillary border of the scapula for the upper two-thirds of its extent, and from two aponeurotic laminae, one of which separates it from the infraspinatus muscle, the other from the teres major muscle. Its fibers run obliquely upwards and laterally; the upper ones end in a tendon which is inserted into the lowest of the three impressions on the greater tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Free Dictionary
''The Free Dictionary'' is an American online dictionary and encyclopedia that aggregates information from various sources. Content The site cross-references the contents of ''The American Heritage Dictionary of the English Language'', the ''Collins English Dictionary'', the ''Columbia Encyclopedia'', the ''Computer Desktop Encyclopedia'', the ''Hutchinson Encyclopedia'' (subscription), and Wikipedia, as well as the Acronym Finder database, several financial dictionaries, legal dictionaries, and other content. It has a feature that allows a user to preview an article while positioning the mouse cursor over a link. One can also double-click on any word to look it up in the dictionary. Site operator The site is run by Farlex, Inc., located in Huntingdon Valley, Pennsylvania. Farlex also maintains a companion title, ''The Free Library'', an online library of out-of-copyright classic books as well as a collection of periodicals of over four million articles dating back to 1984, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminologia Anatomica
''Terminologia Anatomica'' is the international standard for human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology, a program of the International Federation of Associations of Anatomists (IFAA). The second edition was released in 2019 and approved and adopted by the IFAA General Assembly in 2020. ''Terminologia Anatomica'' supersedes the previous standard, ''Nomina Anatomica''. It contains terminology for about 7500 human anatomical structures. Categories of anatomical structures ''Terminologia Anatomica'' is divided into 16 chapters grouped into five parts. The official terms are in Latin. Although equivalent English-language terms are provided, as shown below, only the official Latin terms are used as the basis for creating lists of equivalent terms in other languages. Part I Chapter 1: General anatomy # General terms # Reference planes # Reference lines # Human body positions # Movements # Parts of human body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating cardiac, and respiratory function, helping to control heart rate and breathing rate. It also provides the main motor and sensory nerve supply to the face and neck via the cranial nerves. Ten pairs of cranial nerves come from the brainstem. Other roles include the regulation of the central nervous system and the body's sleep cycle. It is also of prime importance in the conveyance of motor and sensory pathways from the rest of the brain to the body, and from the body back to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamus
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, allowing hub-like exchanges of information. It has several functions, such as the relaying of sensory signals, including motor signals to the cerebral cortex and the regulation of consciousness, sleep, and alertness. Anatomically, it is a paramedian symmetrical structure of two halves (left and right), within the vertebrate brain, situated between the cerebral cortex and the midbrain. It forms during embryonic development as the main product of the diencephalon, as first recognized by the Swiss embryologist and anatomist Wilhelm His Sr. in 1893. Anatomy The thalamus is a paired structure of gray matter located in the forebrain which is superior to the midbrain, near the center of the brain, with nerve fibers projecting out to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of allocortex. It is separated into two cortices, by the longitudinal fissure that divides the cerebrum into the left and right cerebral hemispheres. The two hemispheres are joined beneath the cortex by the corpus callosum. The cerebral cortex is the largest site of neural integration in the central nervous system. It plays a key role in attention, perception, awareness, thought, memory, language, and consciousness. The cerebral cortex is part of the brain responsible for cognition. In most mammals, apart from small mammals that have small brains, the cerebral cortex is folded, providing a greater surface area in the confined volume of the cranium. Apart from minimising brain and cranial volume, cortical folding is crucial for the brain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleus (neuroanatomy)
In neuroanatomy, a nucleus (plural form: nuclei) is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem. The neurons in one nucleus usually have roughly similar connections and functions. Nuclei are connected to other nuclei by tracts, the bundles (fascicles) of axons (nerve fibers) extending from the cell bodies. A nucleus is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up as a region of gray matter, often bordered by white matter. The vertebrate brain contains hundreds of distinguishable nuclei, varying widely in shape and size. A nucleus may itself have a complex internal structure, with multiple types of neurons arranged in clumps (subnuclei) or layers. The term "nucleus" is in some cases used rather loosely, to mean simply an identifiably distinct group of neurons, even if they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Ganglia
The basal ganglia (BG), or basal nuclei, are a group of subcortical nuclei, of varied origin, in the brains of vertebrates. In humans, and some primates, there are some differences, mainly in the division of the globus pallidus into an external and internal region, and in the division of the striatum. The basal ganglia are situated at the base of the forebrain and top of the midbrain. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas. The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, conditional learning, eye movements, cognition, and emotion. The main components of the basal ganglia – as defined functionally – are the striatum, consisting of both the dorsal striatum (caudate nucleus and putamen) and the ventral striatum (nucleus accumbens and olfactory tubercle), the globus pallidus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
