第二心音

第二心音
第二心音，綠色為主要成因，半月瓣的關閉，藍色為次要原因。
基本資料
英文名稱second heart sound
代號S2
波形“dub”、“dup”或“答”
波的性質
頻率60～100Hz
時間長度0.08～0.10秒
主要成因
  • 主動脈瓣關閉
  • 肺動脈瓣關閉
次要成因
  • 血流速度發生改變
  • 房室瓣的開起

在心臟生理學中，第二心音（英語：second heart sound，S2）是一種心音，並且是心動週期中第二個發出的心音，聽起來像是“dub”、“dup”或“答” ，通常由主動脈 (A) 和肺動脈 (P)處發出，發生時間略晚於頸動脈搏，在半月瓣處擁有最大振幅，通常主動脈 (A)會比肺動脈 (P)提早發出。第二心音是一個複合波，振幅僅次於第一心音，頻率最高，歷時較短發生在心室舒張期，並標誌著心室舒張期的開始。[1]

特質

第二心音為複合波，由兩種主要震動和兩種次要震動波組成，主要震動分別為主動脈瓣關閉與肺動脈瓣關閉[2]，前者振幅較後者大。次要震動分別為血流速度發生改變與房室瓣的開起組成，平均頻率約為60～100赫茲，以主動脈瓣關閉時有最大振幅，整體歷時約為0.08秒，平均制振幅較第一心音弱。不与心尖搏动同步，在心底部最响。[3]

第二心音的振幅由主動脈與肺動脈的血壓決定，動脈血壓越高，則第二心音的振幅越大。

成因

第二心音发生在心室舒张期起始，多认为是血流在主动脉与肺动脉内突然减速和半月瓣突然关闭引起瓣膜振动所致。主动脉瓣关闭在前，形成该音的主动脉瓣部分（A2），肺动脉瓣关闭在后，形成该音的肺动脉瓣部分（P2）；正常情况下人耳无法分辨，听诊仅为一个音。其他如房室瓣的开放等因素也参与第二心音的形成。[3]

異常

參見

參考文獻

  1. ^ 医学教育网>临床医学理论>诊断学>第二心音的特点 （页面存档备份，存于互联网档案馆） med66.com [2013-11-30]
  2. ^ Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. The Second Heart Sound （页面存档备份，存于互联网档案馆） Butterworths; 1990. ISBN 0-409-90077-X
  3. ^ 3.0 3.1 陈文彬、潘祥林，诊断学（第8版）152页，人民卫生出版社。ISBN 978-7-117-17077-2

Read other articles:

الدوري النمساوي 1951–52

يفتقر محتوى هذه المقالة إلى الاستشهاد بمصادر. فضلاً، ساهم في تطوير هذه المقالة من خلال إضافة مصادر موثوق بها. أي معلومات غير موثقة يمكن التشكيك بها وإزالتها. (نوفمبر 2019) الدوري النمساوي 1951–52 تفاصيل الموسم الدوري النمساوي  النسخة 41  البلد النمسا  المنظم اتحاد النمسا ...

 

العلاقات اللبنانية الإيرانية

العلاقات اللبنانية الإيرانية     لبنان   إيران تعديل مصدري - تعديل   العلاقات اللبنانية الإيرانية، هي العلاقات الثنائية بين لبنان وإيران. التاريخ بدأت العلاقات الرسمية بين الدولتين في عهد الرئيس اللبناني الراحل كميل شمعون بين عامي 1952 و1958، والتي تزامنت مع تا...

 

Явления Христа ученикам

«Утром после Воскресения». Художник Э. Берн-Джонс Явление Христа ученикам — описанные в Евангелиях случаи явления воскресшего Иисуса Христа Его ученикам до Его Вознесения. Большинство явлений описаны в Евангелии от Иоанна. Содержание 1 Явления у евангелистов 2 Описан...

Cotswolds

Questa voce sull'argomento montagne del Regno Unito è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Coordinate: 52°00′00″N 1°42′00″W / 52°N 1.7°W52; -1.7 La Broadway Tower nelle Cotswolds. Le Cotswolds, anche Cotswold Hills, sono una catena collinare situata nell'area centrale dell'Inghilterra. Sono delimitate a nord dal fiume Avon, a est dalla città di Oxford, a ovest da Cheltenham e a sud dalla valle del Tamigi. Le colli...

 

FFVS J 22

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: FFVS J 22 – news · newspapers · books · scholar · JSTOR (March 2017) (Learn how and when to remove this template message) J 22 An FFVS J 22 on static display at the Swedish Air Force Museum, in the markings of Östgöta Wing (F 3), code L. Role FighterType of a...

 

Vegetarisme Buddhis

Vegetarisme Buddhis adalah praktik vegetarisme dengan porsi yang signifikan dari biksu dan biksuni Mahayana (juga umat perumah tangga) dan beberapa umat Buddha dari sekte lain. Dalam Buddhisme, pandangan tentang vegetarisme berbeda-beda di antara aliran pemikiran yang berbeda. Aliran-aliran Mahayana umumnya menganjurkan diet vegetaris karena Buddha Gautama menetapkan dalam beberapa sutra bahwa para pengikutnya tidak boleh memakan daging makhluk hidup apa pun.[1] Lihat pula Hidangan Bu...

Yahudi Bukhara

Yahudi BukharaJumlah populasisekitar 180.000–250.000 jiwaDaerah dengan populasi signifikan Israel100.000-120.000 Amerika Serikat70.000 Uni Eropa5.000-10.000 Uzbekistan1.500 Tajikistan1-5 Kanada1.500 Rusia1.000 Afghanistan1 Belanda8 [1]BahasaUmumnya Bukhara (dialek dari bahasa Tajik Yahudi), Tajik, Rusia, Ibrani (Israel), Inggris (Amerika Serikat, Kanada, Britania Raya, dan Australia), dan Jerman (Austria dan Jerman) dipakai selain Uzbek b...

 

PNG Air

PNG Air IATA ICAO Kode panggil CG TOK BALUS Didirikan1987PenghubungBandar Udara Internasional JacksonsArmada21Tujuan28Kantor pusatBandar Udara Internasional JacksonsPort Moresby, Papua NuginiTokoh utamaSir John Wild Sr. (chairman)Gary Toomey (CEO)Situs webhttp://www.apng.com PNG Air adalah maskapai penerbangan yang berpusat Bandar Udara Internasional Jacksons, Port Moresby, Papua Nugini.[1] Maskapai ini melayani penerbangan domestik dan internasional dan maskapai ini juga melakukan ko...

 

فوري

فوريالشعارمعلومات عامةالتأسيس 2008 النوع شركة مساهمة — تطبيق محمول المقر الرئيسي القرية الذكية موقع الويب fawry.com (الإنجليزية) المنظومة الاقتصاديةالنشاطات تكنولوجيا مالية، مدفوعات الكترونية، محافظ الكترونية، تمويلمناطق الخدمة مصر الموزعون جوجل بلاي الإيرادات والعائداتا�...

Wörth am Rhein

Questa voce sull'argomento centri abitati della Renania-Palatinato è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti del progetto di riferimento. WörthCittà, indipendente dalle VerbandsgemeindeWörth am Rhein Wörth – VedutaIl vecchio municipio LocalizzazioneStato Germania Land Renania-Palatinato DistrettoNon presente CircondarioGermersheim TerritorioCoordinate49°03′N 8°16′E / 49.05°N 8.266667°E4...

 

Gian Piero Ventura

Italian football manager Gian Piero Ventura Ventura in 2019Personal informationFull name Gian Piero Ventura[1]Date of birth (1948-01-14) 14 January 1948 (age 76)Place of birth Genoa, ItalyPosition(s) MidfielderYouth career SampdoriaSenior career*Years Team Apps (Gls)1968–1969 Sampdoria 0 (0)1969–1970 Sestrese 29 (0)1970–1974 Enna 9 (0)1974–1976 Sanremese 21 (0)1976–1978 Novese 30 (0)Managerial career1976–1979 Sampdoria (youth team)1979–1981 Sampdoria (assistant coac...

 

George W. Bush

President of the United States from 2001 to 2009 This article is about the 43rd president of the United States. For his father, the 41st president, see George H. W. Bush. George W. BushOfficial portrait, 200343rd President of the United StatesIn officeJanuary 20, 2001 – January 20, 2009Vice PresidentDick CheneyPreceded byBill ClintonSucceeded byBarack Obama46th Governor of TexasIn officeJanuary 17, 1995 – December 21, 2000Lieutenant Bob Bullock Rick Perry Preceded by...

Differential association

Theory in crimonology This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (April 2020) (Learn how and when to remove this message) Criminology and penology Theory Anomie Biosocial criminology Broken windows Collective efficacy Crime analysis Criminalization Differential association Deviance Expressive function of law Labeling theory Psychopathy Rational choice Ris...

 

1999 World Championships in Athletics – Women's 800 metres

Women's 800 metres at the 1999 World ChampionshipsVenueEstadio OlímpicoDates21 August (heats)22 August (semifinals)24 August (final)Competitors37 from 31 nationsWinning time1:56.68Medalists  Ludmila Formanová Czech Republic (CZE) Maria de Lurdes Mutola Mozambique (MOZ) Svetlana Masterkova Russia (RUS)← 19972001 → Events at the1999 World ChampionshipsTrack events100 mmenwomen200 mmenwomen400 mmenwome...

 

Maximian

Roman emperor from 286 to 305 For other people named Maximian, see Maximian (disambiguation). MaximianPortrait head, Musée Saint-Raymond[1]Roman emperor (in the West) Augustus1 April 286 – 1 May 305 (with Diocletian in the East)[2]PredecessorDiocletian (alone)SuccessorConstantius ICaesar21 or 25 July 285 – 286Augustus (rebelled)Late 306 – 11 November 308310 (briefly)BornMaximianusc. 250Sirmium (present-day Sremska Mitrovica, Serbia)Diedc. ...

Culture of Mongolia

Altar of 9th Jebtsundamba Khutughtu - the spiritual leader of the Gelug lineage among the Khalkha Mongols. Gandantegchinlen Monastery, Ulaanbaatar, Mongolia. The culture of Mongolia has been shaped by the country's nomadic tradition and its position at the crossroads of various empires and civilizations. Mongolian culture is influenced by the cultures of the Mongolic, Turkic, and East Asian peoples, as well as by the country's geography and its history of political and economic interactions ...

 

St Wilfrid's Church, Preston

Church in Preston, Lancashire, England Church in Lancashire, United KingdomSt. Wilfrid's PrestonCatholic Church of Saint Wilfrid, PrestonNorth end of St Wilfrid's Church, Chapel Street, PrestonSt. Wilfrid's PrestonLocation in Preston53°45′27″N 2°42′10″W / 53.757478°N 2.702855°W / 53.757478; -2.702855OS grid referenceSD5376529221LocationPreston, LancashireCountryUnited KingdomDenominationRoman CatholicWebsitehttp://stwilfridsparish.uk/HistoryStatusActiveFoun...

 

Duff Cooper

Questa voce sull'argomento politici britannici è solo un abbozzo. Contribuisci a migliorarla secondo le convenzioni di Wikipedia. Segui i suggerimenti del progetto di riferimento. Alfred Duff Cooper Alfred Duff Cooper, 1° Visconte di Norwich (Londra, 22 febbraio 1890 – oceano Atlantico, 1º gennaio 1954), è stato un politico britannico. Indice 1 Biografia 2 Ascendenza 3 Opere tradotte in italiano 4 Opere in inglese 5 Bibliografia 6 Altri progetti 7 Collegamenti esterni Biografia De...

Bullwheel

Wheel on which a rope turns For USS Bullwheel, see List of United States Navy ships: A–B. A chairlift's return bullwheel A bullwheel of a tricable gondola lift A bullwheel or bull wheel is a large wheel on which a rope turns, such as in a chairlift or other ropeway. In this application, the bullwheel that is attached to the prime mover is called the drive bullwheel, and the other is the return bullwheel. One of the bullwheels is usually attached to a cable tensioning system, which is usuall...

 

Teslin Lake

Lake in western Canada Teslin LakeTeslin LakeLocationBritish Columbia/YukonCoordinates60°1′N 132°26′W / 60.017°N 132.433°W / 60.017; -132.433Primary inflowsHayes River, Jennings River, Swift River, Teslin RiverPrimary outflowsTeslin RiverBasin countriesCanadaMax. length120 km (75 mi)Max. width5 km (3.1 mi)Surface area791 km2 (305 sq mi)Average depth59 m (194 ft)Max. depth214 m (702 ft)Surface elevation...