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Vagal Response
Reflex syncope is a brief loss of consciousness due to a neurologically induced drop in blood pressure and/or a decrease in heart rate. Before an affected person passes out, there may be sweating, a decreased ability to see, or ringing in the ears. Occasionally, the person may twitch while unconscious. Complications of reflex syncope include injury due to a fall. Reflex syncope is divided into three types: vasovagal, situational, and carotid sinus. Vasovagal syncope is typically triggered by seeing blood, pain, emotional stress, or prolonged standing. Situational syncope is often triggered by urination, swallowing, or coughing. Carotid sinus syncope is due to pressure on the carotid sinus in the neck. The underlying mechanism involves the nervous system slowing the heart rate and dilating blood vessels, resulting in low blood pressure and thus not enough blood flow to the brain. Diagnosis is based on the symptoms after ruling out other possible causes. Recovery from a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagus Nerve
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves—but they are typically referred to collectively as a single subsystem. The vagus is the longest nerve of the autonomic nervous system in the human body and comprises both sensory and motor fibers. The sensory fibers originate from neurons of the nodose ganglion, whereas the motor fibers come from neurons of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The vagus was also historically called the pneumogastric nerve. Structure Upon leaving the medulla oblongata between the olive and the inferior cerebellar peduncle, the vagus nerve extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotid Sinus
In human anatomy, the carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage. The carotid sinus extends from the bifurcation to the "true" internal carotid artery. The carotid sinus is sensitive to pressure changes in the arterial blood at this level. It is the major baroreception site in humans and most mammals. Structure The carotid sinus is the reflex area of the carotid artery, consisting of baroreceptors which monitor blood pressure. Function The carotid sinus contains numerous baroreceptors which function as a "sampling area" for many homeostatic mechanisms for maintaining blood pressure. The carotid sinus baroreceptors are innervated by the carotid sinus nerve, which is a branch of the glossopharyngeal nerve (CN IX). The neurons which innervate the carotid sinus centrally project to the solitary nucleus in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagal
The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves—but they are typically referred to collectively as a single subsystem. The vagus is the longest nerve of the autonomic nervous system in the human body and comprises both sensory and motor fibers. The sensory fibers originate from neurons of the nodose ganglion, whereas the motor fibers come from neurons of the dorsal motor nucleus of the vagus and the nucleus ambiguus. The vagus was also historically called the pneumogastric nerve. Structure Upon leaving the medulla oblongata between the olive and the inferior cerebellar peduncle, the vagus nerve extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest, and abdom ... [...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 s ... [...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 bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleus Tractus Solitarii
In the human brainstem, the solitary nucleus, also called nucleus of the solitary tract, nucleus solitarius, and nucleus tractus solitarii, (SN or NTS) is a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column of grey matter embedded in the medulla oblongata. Through the center of the SN runs the solitary tract, a white bundle of nerve fibers, including fibers from the facial, glossopharyngeal and vagus nerves, that innervate the SN. The SN projects to, among other regions, the reticular formation, parasympathetic preganglionic neurons, hypothalamus and thalamus, forming circuits that contribute to autonomic regulation. Cells along the length of the SN are arranged roughly in accordance with function; for instance, cells involved in taste are located in the rostral part, while those receiving information from cardio-respiratory and gastrointestinal processes are found in the caudal part. Inputs * Taste information from the facial nerve via the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micturition Syncope
Micturition syncope or post-micturition syncope is the name given to the human phenomenon of fainting shortly after or during urination. The underlying cause is not fully understood, but it may be a result of vasovagal response, postural hypotension, or a combination thereof. People often become pale, lightheaded, nauseated, sweaty and weak before they lose consciousness. Sometimes defecating, coughing, or severe vomiting may cause fainting in a similar way. Causes When one strains to increase the flow of urine, it stimulates the vagus nerve (usually more pronounced in elderly men with large prostates). The vagus nerve stimulus causes slowing down of the heart (bradycardia) and a drop in blood pressure. The heart cannot perform effectively as a pump because insufficient blood comes to it. It can be associated with a very rare tumour known as a paraprostatic pheochromocytoma within the urinary bladder. Treatment There is no specific treatment for micturition syncope. General ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcranial Magnetic Stimulation
Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse generator, or stimulator, is connected to a magnetic coil connected to the scalp. The stimulator generates a changing electric current within the coil which creates a varying magnetic field, inducing a current within a region in the brain itself.NICE. January 201Transcranial magnetic stimulation for treating and preventing migraine/ref>Michael Craig Miller for Harvard Health Publications. July 26, 201Magnetic stimulation: a new approach to treating depression?/ref> TMS has shown diagnostic and therapeutic potential in the central nervous system with a wide variety of disease states in neurology and mental health, with research still evolving. Adverse effects of TMS appear rare and include fainting and seizure. Other potential issues inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fear Of Needles
Fear of needles, known in medical literature as needle phobia, is the extreme fear of medical procedures involving injections or hypodermic needles. This can lead to avoidance of medical care, including vaccine hesitancy. It is occasionally referred to as '' aichmophobia'', although this term may also refer to a more general fear of sharply pointed objects. Overview and incidence The condition was officially recognized in 1994 in the DSM-IV ( Diagnostic and Statistical Manual of Mental Disorders, 4th edition) as a specific phobia of blood-injection-injury type phobia (BII phobia). Phobic level responses to injections cause sufferers to avoid inoculations, blood tests, and in the more severe cases, all medical care. It is estimated that at least 10% of American adults have a fear of needles, and it is likely that the actual number is larger, as the most severe cases are never documented due to the tendency of the sufferer to avoid all medical treatment. The diagnosis crite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Phobia
Blood phobia (also known as hemophobia or hematophobia in American English and haemophobia or haematophobia in British English) is an extreme irrational fear of blood, a type of specific phobia. Severe cases of this fear can cause physical reactions that are uncommon in most other fears, specifically vasovagal syncope (fainting). Similar reactions can also occur with trypanophobia and traumatophobia. For this reason, these phobias are categorized as blood-injection-injury phobia by the DSM-IV. Some early texts refer to this category as "blood-injury-illness phobia." Causes Blood phobia is often caused by direct or vicarious trauma in childhood. Though some have suggested a possible genetic link, a study of twins suggests that social learning and traumatic events, rather than genetics, is of greater significance.. Blood-injection-injury phobia (BII) affects about 4% of the population in the United States. The inclusion of BII within the category of specific or simple phob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 internal organs, smooth muscle and glands. The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions, such as the heart rate, its force of contraction, digestion, respiratory rate, pupillary response, urination, and sexual arousal. This system is the primary mechanism in control of the fight-or-flight response. The autonomic nervous system is regulated by integrated reflexes through the brainstem to the spinal cord and organs. Autonomic functions include control of respiration, cardiac regulation (the cardiac control center), vasomotor activity (the vasomotor center), and certain reflex actions such as coughing, sneezing, swallowing and vomiting. Those are then subdivided into other areas and are also linked to autonomic subsystems and the peripheral nervous syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epileptic Seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness (tonic-clonic seizure), to shaking movements involving only part of the body with variable levels of consciousness (focal seizure), to a subtle momentary loss of awareness (absence seizure). Most of the time these episodes last less than two minutes and it takes some time to return to normal. Urinary incontinence, Loss of bladder control may occur. Seizures may be provoked and unprovoked. Provoked seizures are due to a temporary event such as low blood sugar, alcohol withdrawal, abusing alcohol together with prescription medication, low blood sodium, fever, brain infection, or concussion. Unprovoked seizures occur without a known or fixable cause such that ongoing seizures are likely. Unprovoked seizur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
