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Encyclopedia > Carotid sinus
Arteries of the neck. The carotid sinus is at the origin of the internal carotid artery.
Arteries of the neck. The carotid sinus is at the origin of the internal carotid artery.

In human anatomy, the carotid sinus is a localized dilation of the internal carotid artery at its origin, the common carotid artery bifurcation. It contains numerous baroreceptors, which function as a "sampling area" for many homeostatic mechanisms for maintaining blood pressure. Manual stimulation of the carotid sinus can induce the carotid sinus reflex, which may reduce the heart rate and/or blood pressure to some degree.[1] Image File history File links Download high resolution version (600x864, 102 KB) Summary The internal carotid and vertebral arteries from the right side. ... Image File history File links Download high resolution version (600x864, 102 KB) Summary The internal carotid and vertebral arteries from the right side. ... The carotid artery is a major artery of the head and neck that supplies blood to the head and neck. ... Human anatomy or anthropotomy is a special field within anatomy. ... The carotid artery is a major artery of the head and neck that supplies blood to the head and neck. ... Left Common Carotid Artery- One of three arteries that originate along the aortic arch. ... Baroreceptors (or baroceptors) in the human body detect the pressure of blood flowing though them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. ... Heart rate is a term used to describe the frequency of the cardiac cycle. ... Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. ...

Contents


Disease of the carotid sinus

The carotid sinus often has atherosclerotic plaques because of disturbed hemodynamics (low wall shear stress, flow reversal/recirculation).[2] Since these plaques, if large and unstable, predispose to ischemic strokes and transient ischemic attacks, carotid endarterectomies are frequently done for prophylaxis. Atherosclerosis is a disease of arterial blood vessels. ... Hemodynamics is concerned with the forces generated by the heart and the motion of blood through the cardiovascular system. ... In physics, shear stress is a stress state in which the shape of a material tends to change (usually by sliding forces -- torque by transversely-acting forces) without particular volume change. ... A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ... Transient ischemic attacks (TIA) are caused by temporary disturbance of blood supply to a restricted area of brain and cause recurrent and brief (less than 24 hours) neurologic dysfunctions. ... Carotid entarterectomy is a surgical procedure used to correct carotid stenosis (obstruction of the carotid artery by atheroma), used particularly when this causes medical problems, such as transient ischemic attacks (TIAs) or cerebrovascular accidents (CVAs, strokes). ... Prophylaxis refers to any medical or public health procedure whose purpose is to prevent, rather than treat or cure, disease. ...


The carotid sinus can be oversensitive to manual stimulation, a condition known as carotid sinus hypersensitivity, carotid sinus syndrome or carotid sinus syncope, in which manual stimulation causes large changes in heart rate and/or blood pressure.[1] Heart rate is a term used to describe the frequency of the cardiac cycle. ... Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. ...


Carotid sinus massage

Massage of the carotid sinus, carotid sinus massage is used to diagnose carotid sinus syncope and is sometimes useful for differentiating supraventricular tachycardia (SVT) from ventricular tachycardia. It, like the valsalva maneuver, is a therapy for SVT.[3] However, it is less effective than pharmaceutical management of SVT with verapamil or adenosine.[4] To meet Wikipedias quality standards, this article or section may require cleanup. ... A supraventricular tachycardia (SVT) is a rapid rhythm of the heart in which the origin of the electrical signal is either the atria or the AV node. ... Tachycardia is an abnormally rapid beating of the heart, defined as a resting heart rate of over 100 beats per minute. ... A Valsalva maneuver is any attempted exhalation against a closed glottis or against a closed mouth and nose. ... Verapamil (brand names: Isoptin®, Verelan®, Calan®) is a medical drug that acts as an L-type calcium channel blocker. ... The chemical structure of adenosine Adenosine is a nucleoside comprised of adenine attached to a ribose (ribofuranose) moiety via a β-N9-glycosidic bond. ...


Carotid sinus reflex death

Carotid sinus reflex death is a disputed mechanism of death in which manual stimulation of the carotid sinus alledgedly causes strong vagus nerve impulses leading to terminal cardiac arrest. Carotid sinus reflex death has been pointed out as a possible cause of death in cases of strangulation and hanging, but such deductions remain controversial. Studies have however shown that the carotid sinus reflex can be a contributing factor in other mechanisms of death by reducing blood pressure and heart rate, especially in the elderly or in people suffering from carotid sinus hypersensitivity. [5] Death is the cessation of physical life in a living organism, or the state of the organism after that event. ... The vagus nerve is tenth of twelve paired cranial nerves and is the only nerve that starts in the brainstem (somewhere in the medulla oblongata) and extends all the way down past the head, right down to the abdomen. ... Hanging is a form of execution or a method for suicide. ... Blood pressure is the pressure exerted by the blood on the walls of the blood vessels. ... Heart rate is a term used to describe the frequency of the cardiac cycle. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ...


References

  1. a b Wijetunga, M; Schatz, I. Carotid Sinus Hypersensitivity. www.emedicine.com. URL last accessed February 28, 2006
  2. Glagov S, Zarins C, Giddens DP, Ku DN. Hemodynamics and atherosclerosis. Insights and perspectives gained from studies of human arteries. Arch Pathol Lab Med. 1988 Oct;112(10):1018-31. PMID 3052352
  3. Lim SH, Anantharaman V, Teo WS, Goh PP, Tan AT. Comparison of treatment of supraventricular tachycardia by Valsalva maneuver and carotid sinus massage. Ann Emerg Med. 1998 Jan;31(1):30-5. PMID 9437338
  4. Ballo P, Bernabo D, Faraguti SA. Heart rate is a predictor of success in the treatment of adults with symptomatic paroxysmal supraventricular tachycardia. Eur Heart J. 2004 Aug;25(15):1310-7. PMID 15288158
  5. Passig ,K. Carotid Sinus reflex death - a theory and its history. www.datenschlag.org. URL last accessed February 28, 2006.

  Results from FactBites:
 
THE MERCK MANUAL OF GERIATRICS, Ch. 18, Syncope (3398 words)
Carotid sinus hypersensitivitycan cause syncope when neck movement, a tight collar, or a tumor or other lesion at the carotid bifurcation stimulates baroreceptors in the carotid sinus, resulting in excessive slowing of the heart, vasodilation, or both.
Carotid sinus syndrome refers to symptomatic carotid sinus hypersensitivity and is defined by a sinus pause that lasts > 3 sec (cardioinhibitory response) or a drop in systolic BP of > 50 mm Hg (vasodepressor response) during carotid sinus massage.
Carotid sinus massage should be done to detect carotid sinus hypersensitivity when no other cause of syncope is apparent, but only in patients who have no evidence of cerebrovascular disease (eg, carotid bruit, previous stroke, transient ischemic attacks) or cardiac conduction abnormalities.
eMedicine - Carotid Sinus Hypersensitivity : Article by Mevan N Wijetunga, MD (2188 words)
Afferent impulses are transmitted by the carotid sinus, glossopharyngeal, and vagus nerves to the nuclei tractus solitarius and the para median nucleus in the brain stem.
The term induced carotid sinus syndrome refers to a clinical situation in which a patient has no clear history of accidental mechanical manipulation of the carotid sinuses and has a negative result from workup for syncope, except for a hypersensitive response to carotid sinus massage, which can be attributed to the patient's symptoms.
Permanent pacing is discouraged in patients with a hypersensitive cardioinhibitory response to carotid sinus stimulation in the absence of symptoms.
  More results at FactBites »

 
 

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