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Ventral Posterior Nucleus
The ventral posterior nucleus is the somatosensory relay nucleus in thalamus of the brain. Input and output The ventral posterior nucleus receives neuronal input from the medial lemniscus, spinothalamic tracts, and trigeminothalamic tract. It projects to the somatosensory cortex and the ascending reticuloactivation system. Subdivisions The ventral posterior nucleus is divided into: *Ventral posterolateral nucleus, which receives sensory information from the body via the medial lemniscus, and spinothalamic tracts. *Ventral posteromedial nucleus, which receives sensory information from the head and face via the trigeminal nerve. *Ventral intermediate nucleus, implicated in oscillatory tremor generation in Parkinson's disease and essential tremor. Function The ventral posterior nucleus has, by virtue of its afferent and efferent pathways, crucial relay and regulatory roles in touch, body position, pain, temperature, itch, taste, and arousal. Additionally, the VPN—and particul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midline Nuclear Group
The midline nuclear group (or midline thalamic nuclei) is a region of the thalamus consisting of the following nuclei: * Paraventricular thalamus, paraventricular nucleus of thalamus (''nucleus paraventricularis thalami'') - not to be confused with paraventricular nucleus of hypothalamus * paratenial nucleus (''nucleus parataenialis'') * nucleus reuniens (also known as the medioventral nucleus) * rhomboidal nucleus (''nucleus commissuralis rhomboidalis'') * subfascicular nucleus (''nucleus subfascicularis'') The List of regions in the human brain#Thalamus, midline nuclei are often called "nonspecific" in that they project widely to the cortex and elsewhere. This has led to the assumption that they may be involved in general functions such as alerting. However, anatomical connections might suggest more specific functions, with the paraventricular and paratenial nuclei involved in viscero-limbic functions, and the reuniens and rhomboid nuclei involved in multimodal sensory processin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Lemniscus
The medial lemniscus, also known as Reil's band or Reil's ribbon (for German anatomist Johann Christian Reil), is a large ascending bundle of heavily myelinated axons that decussate in the 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 conti ..., specifically in the medulla oblongata. The medial lemniscus is formed by the crossings of the internal arcuate fibers. The internal arcuate fibers are composed of axons of the gracile nucleus and the cuneate nucleus. The cell bodies of the nuclei lie contralaterally. The medial lemniscus is part of the somatosensory dorsal column–medial lemniscus pathway, which ascends in the spinal cord to the thalamus.Kamali A, Kramer LA, Butler IJ, Hasan KM. Diffusion tensor tractography of the somatosensory system in the human brains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arousal
Arousal is the physiology, physiological and psychology, psychological state of being awoken or of Five senses, sense organs stimulated to a point of perception. It involves activation of the ascending reticular activating system (ARAS) in the human brain, brain, which mediates wakefulness, the autonomic nervous system, and the endocrine system, leading to increased heart rate and blood pressure and a condition of sensory alertness, desire, mobility, and reactivity. Arousal is mediated by several neural systems. Wakefulness is regulated by the ARAS, which is composed of projections from five major neurotransmitter systems that originate in the brainstem and form connections extending throughout the Cerebral cortex, cortex; activity within the ARAS is regulated by neurons that release the neurotransmitters norepinephrine, acetylcholine, dopamine, serotonin and histamine. Activation of these neurons produces an increase in cortical activity and subsequently alertness. Arousal is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taste
The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste. Taste is the perception stimulated when a substance in the mouth biochemistry, reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue. Taste, along with olfaction, the sense of smell and trigeminal nerve stimulation (registering texture, pain, and temperature), determines Flavoring, flavors of food and other substances. Humans have taste receptors on taste buds and other areas, including the upper surface of the tongue and the epiglottis. The gustatory cortex is responsible for the perception of taste. The tongue is covered with thousands of small bumps called lingual papillae, papillae, which are visible to the naked eye. Within each papilla are hundreds of taste buds. The exceptions to this is the filiform papillae that do not contain taste buds. There are between 2000 and 5000Boron, W.F., E.L. Boulpaep. 200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itch
An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex, whereas itches leads to a scratch reflex. Unmyelinated nerve fibers for itches and pain both originate in the skin. Information for them is conveyed centrally in two distinct systems that both use the same nerve bundle and spinothalamic tract. Classification Most commonly, an itch is felt in one place. If it is felt all over the body, then it is called ''generalized itch'' or ''generalized pruritus''. Generalized itch is infrequently a symptom of a serious underlying condition, such as cholestatic liver disease. If the sensation of itching persists for six weeks or longer, then it is called ''chronic itch'' or ''c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making up a substance. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), with the third being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pain
Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." Pain motivates organisms to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Congenital insensitivity to pain may result in reduced life expectancy. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease. Pain is the most common reason for physician consultation in most developed countries. It is a major symptom in many medical conditions, and can interfere with a person's quality of life and general fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Position
Human positions refer to the different physical configurations that the human body can take. There are several synonyms that refer to human positioning, often used interchangeably, but having specific nuances of meaning. *''Position'' is a general term for a configuration of the human body. *''Posture'' means an intentionally or habitually assumed position. *''Pose'' implies an artistic, aesthetic, athletic, or spiritual intention of the position. *''Attitude'' refers to postures assumed for purpose of imitation, intentional or not, as well as in some standard collocations in reference to some distinguished types of posture: "Freud never assumed a fencer's attitude, yet almost all took him for a swordsman." *''Bearing'' refers to the manner of the posture, as well as of gestures and other aspects of the conduct taking place. Basic positions While not moving, a human is usually in one of the following basic positions: All-fours This is the static form of crawling which is a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Touch
The somatosensory system, or somatic sensory system is a subset of the sensory nervous system. The main functions of the somatosensory system are the perception of external stimuli, the perception of internal stimuli, and the regulation of body position and balance ( proprioception). It is believed to act as a pathway between the different sensory modalities within the body. As of 2024 debate continued on the underlying mechanisms, correctness and validity of the somatosensory system model, and whether it impacts emotions in the body. The somatosensory system has been thought of as having two subdivisions; *one for the detection of mechanosensory information related to touch. Mechanosensory information includes that of light touch, vibration, pressure and tension in the skin. Much of this information belongs to the sense of touch which is a general somatic sense in contrast to the special senses of sight, smell, taste, hearing, and balance. * one for the nociception ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Tremor
Essential tremor (ET), also called benign tremor, familial tremor, and idiopathic tremor, is a medical condition characterized by involuntary rhythmic contractions and relaxations ( oscillations or twitching movements) of certain muscle groups in one or more body parts of unknown cause. It is typically symmetrical, and affects the arms, hands, or fingers; but sometimes involves the head, vocal cords, or other body parts. Essential tremor is either an ''action'' (intention) tremor—it intensifies when one tries to use the affected muscles during voluntary movements such as eating and writing—or it is a ''postural'' tremor, which occurs when holding arms outstretched and against gravity. This means that it is distinct from a resting tremor, such as that caused by Parkinson's disease, which is not correlated with movement. Unlike Parkinson's disease, essential tremor may worsen with action. Essential tremor is a progressive neurological disorder, and the most common movement di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkinson's Disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become more prevalent as the disease progresses. The motor symptoms are collectively called parkinsonism and include tremors, bradykinesia, spasticity, rigidity as well as postural instability (i.e., difficulty maintaining balance). Non-motor symptoms develop later in the disease and include behavior change (individual), behavioral changes or mental disorder, neuropsychiatric problems such as sleep abnormalities, psychosis, anosmia, and mood swings. Most Parkinson's disease cases are idiopathic disease, idiopathic, though contributing factors have been identified. Pathophysiology involves progressive nerve cell death, degeneration of nerve cells in the substantia nigra, a midbrain region that provides dopamine to the basal ganglia, a system invo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigeminal Nerve
In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name (''trigeminal'', ) derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V), the maxillary nerve (V), and the mandibular nerve (V). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or "cutaneous") functions. Adding to the complexity of this nerve is that Autonomic nervous system, autonomic nerve fibers as well as special sensory fibers (taste) are contained within it. The motor division of the trigeminal nerve derives from the Basal plate (neural tube), basal plate of the embryonic pons, and the sensory division originates in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
