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Baroreflex
The baroreflex or baroreceptor reflex is one of the body's homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels. The baroreflex provides a rapid negative feedback loop in which an elevated blood pressure causes the heart rate to decrease. Decreased blood pressure decreases baroreflex activation and causes heart rate to increase and to restore blood pressure levels. Their function is to sense pressure changes by responding to change in the tension of the arterial wall. The baroreflex can begin to act in less than the duration of a cardiac cycle (fractions of a second) and thus baroreflex adjustments are key factors in dealing with postural hypotension, the tendency for blood pressure to decrease on standing due to gravity. The system relies on specialized neurons, known as baroreceptors, chiefly in the aortic arch and carotid sinuses, to monitor changes in blood pressure and relay them to the medulla oblongata. Baroreceptors are stretch recep ... [...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 sinuses are sensitive to pressure changes in the arterial blood at this level. They are two out of the four baroreception sites 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baroreceptors
Baroreceptors (or archaically, pressoreceptors) are stretch receptors that sense blood pressure. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous system. This sensory information is used primarily in autonomic reflexes that in turn influence the heart cardiac output and vascular smooth muscle to influence vascular resistance. Baroreceptors act immediately as part of a negative feedback system called the baroreflex as soon as there is a change from the usual mean arterial blood pressure, returning the pressure toward a normal level. These reflexes help regulate short-term blood pressure. The solitary nucleus in the medulla oblongata of the brain recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance. Baroreceptors can be divided into two categories based on the type of blood vessel in which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baroreceptor
Baroreceptors (or archaically, pressoreceptors) are stretch receptors that sense blood pressure. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous system. This sensory information is used primarily in autonomic reflexes that in turn influence the heart cardiac output and vascular smooth muscle to influence vascular resistance. Baroreceptors act immediately as part of a negative feedback system called the baroreflex as soon as there is a change from the usual mean arterial blood pressure, returning the pressure toward a normal level. These reflexes help regulate short-term blood pressure. The solitary nucleus in the medulla oblongata of the brain recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance. Baroreceptors can be divided into two categories based on the type of blood vessel in whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Feedback Loop
Negative feedback (or balancing feedback) occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances. Whereas positive feedback tends to instability via exponential growth, oscillation or chaotic behavior, negative feedback generally promotes stability. Negative feedback tends to promote a settling to equilibrium, and reduces the effects of perturbations. Negative feedback loops in which just the right amount of correction is applied with optimum timing, can be very stable, accurate, and responsive. Negative feedback is widely used in mechanical and electronic engineering, and it is observed in many other fields including biology, chemistry and economics. General negative feedback systems are studied in control systems engineering. Negative feedback loops also play an integral role in maintaining the atmospher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthostatic Hypotension
Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when they are standing up ( orthostasis) or sitting down. Primary orthostatic hypotension is also often referred to as neurogenic orthostatic hypotension. The drop in blood pressure may be sudden ( vasovagal orthostatic hypotension), within 3 minutes (classic orthostatic hypotension) or gradual (delayed orthostatic hypotension). It is defined as a fall in systolic blood pressure of at least 20 mmHg or diastolic blood pressure of at least 10 mmHg after 3 minutes of standing. It occurs predominantly by delayed (or absent) constriction of the lower body blood vessels, which is normally required to maintain adequate blood pressure when changing the position to standing. As a result, blood pools in the blood vessels of the legs for a longer period, and less is returned to the heart, thereby leading to a reduced cardiac output and inadequate blood flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic Nervous System
The sympathetic nervous system (SNS or SANS, sympathetic autonomic nervous system, to differentiate it from the somatic nervous system) 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. The latter stimulates the body to "feed and breed" and to (then) "rest-and-digest". The SNS has a major role in various physiological processes such as blood glucose levels, body temperature, cardiac output, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solitary Nucleus
The solitary nucleus (SN) (nucleus of the solitary tract, nucleus solitarius, or nucleus tractus solitarii) is a series of neurons whose cell bodies form a roughly vertical column of grey matter in the medulla oblongata of the brainstem. Their axons form the bulk of the enclosed solitary tract. The solitary nucleus can be divided into different parts including dorsomedial, dorsolateral, and ventrolateral subnuclei. The solitary nucleus receives general visceral and special visceral inputs from the facial nerve (CN VII), glossopharyngeal nerve (CN IX) and vagus nerve (CN X); it receives and relays stimuli related to taste and visceral sensation. It sends outputs to various parts of the brain, such as the hypothalamus, thalamus, and reticular formation, 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 rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rostral Ventrolateral Medulla
The rostral ventrolateral medulla (RVLM), also known as the pressor area of the medulla, is a part of the ventrolateral medulla in the brainstem responsible for basal and reflex control of sympathetic activity associated with cardiovascular function. Abnormally elevated sympathetic activity in the RVLM is associated with various cardiovascular diseases, such as heart failure and hypertension. The RVLM is notably involved in the baroreflex. It receives inhibitory GABAergic input from the caudal ventrolateral medulla (CVLM). The RVLM is a primary regulator of the sympathetic nervous system; it sends catecholaminergic projections to the sympathetic preganglionic neurons in the intermediolateral nucleus of the spinal cord via reticulospinal tract. Physostigmine, a choline-esterase inhibitor, elevates endogenous levels of acetylcholine and causes a rise in blood pressure by stimulation of the RVLM. Orexinergic neurons from the lateral hypothalamus The lateral hypothalamus (L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Ventrolateral Medulla
The ventrolateral medulla, part of the medulla oblongata of the brainstem, plays a major role in regulating arterial blood pressure and breathing. It regulates blood pressure by regulating the activity of the sympathetic nerves that target the heart and peripheral blood vessels. The ventrolateral medulla consists of a rostral ventrolateral medulla (RVLM) and a caudal ventrolateral medulla (CVLM). Neurons in the RVLM project directly to preganglionic neurons in the spinal cord and maintain tonic activity in the sympathetic vasomotor nerves. This activity is inhibited by GABA GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GA ... output from the CVLM. References Sympathetic nervous system Reflexes Medulla oblongata Cardiovascular physiology {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vagus Nerve
The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibers and serves as a major pathway that connects the brain to various organs, including the heart, lungs, and digestive tract. As a key part of the parasympathetic nervous system, the vagus nerve helps regulate essential involuntary functions like heart rate, breathing, and digestion. By controlling these processes, the vagus nerve contributes to the body's "rest and digest" response, helping to calm the body after stress, lower heart rate, improve digestion, and maintain homeostasis. The vagus nerve consists of two branches: the right and left vagus nerves. In the neck, the right vagus nerve contains approximately 105,000 fibers, while the left vagus nerve has about 87,000 fibers, according to one source. However, other sources report sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamatergic
Glutamatergic means "related to glutamate". A glutamatergic agent (or drug) is a chemical that directly modulates the excitatory amino acid (glutamate/aspartate) system in the body or brain. Examples include excitatory amino acid receptor agonists, excitatory amino acid receptor antagonists, and excitatory amino acid reuptake inhibitors. See also * Adenosinergic * Adrenergic * Cannabinoidergic * Cholinergic * Dopaminergic Dopaminergic means "related to dopamine" (literally, "working on dopamine"), a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain. Dopaminergic pathways, Dopaminergic brain pathways facil ... * GABAergic * GHBergic * Glycinergic * Histaminergic * Melatonergic * Monoaminergic * Opioidergic * Serotonergic * Sigmaergic References Neurochemistry Neurotransmitters {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2116 Baroreceptor Reflex Flow Art , synthetic chemical element with atomic number 116
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116 (''one hundred and sixteen'') may refer to: *116 (number) *AD 116 *116 BC *116 (Devon and Cornwall) Engineer Regiment, Royal Engineers, a military unit *116 (MBTA bus) *116 (New Jersey bus) *116 (hip hop group), a Christian hip hop collective *116 emergency number, see List of emergency telephone numbers ** 116 emergency telephone number in California *116 helplines in Europe *Route 116, see list of highways numbered 116 * 116 Sirona, a main-belt asteroid See also * 11/6 (other) * *Livermorium Livermorium is a synthetic chemical element; it has symbol Lv and atomic number 116. It is an extremely radioactive element that has only been created in a laboratory setting and has not been observed in nature. The element is named after the La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
