sino-atrial node

洞房結節

関

SA node、sinoatrial node、sinus node

WordNet

1. used to express refusal or denial or disagreement etc or especially to emphasize a negative statement; "no, you are wrong"
2. a negative; "his no was loud and clear"
3. referring to the degree to which a certain quality is present; "he was no heavier than a child" (同)no more
4. not in any degree or manner; not at all; "he is no better today"
5. quantifier; used with either mass nouns or plural count nouns for indicating a complete or almost complete lack or zero quantity of; "we have no bananas"; "no eggs left and no money to buy any"; "have you no decency?"; "did it with no help"; "Ill get you there in no time"
6. sway gently back and forth, as in a nodding motion; "the flowers were nodding in the breeze"
7. be almost asleep; "The old man sat nodding by the fireplace"
8. let the head fall forward through drowsiness; "The old man was nodding in his chair"
9. the act of nodding the head
10. a sign of assent or salutation or command
11. express or signify by nodding; "He nodded his approval"
12. lower and raise the head, as to indicate assent or agreement or confirmation; "The teacher nodded when the student gave the right answer"
13. any thickened enlargement (同)knob, thickening
14. (botany) the small swelling that is the part of a plant stem from which one or more leaves emerge (同)leaf node
15. a connecting point at which several lines come together
16. (computer science) any computer that is hooked up to a computer network (同)client, guest
17. (astronomy) a point where an orbit crosses a plane
18. (physics) the point of minimum displacement in a periodic system
19. any bulge or swelling of an anatomical structure or part
20. commit a sin; violate a law of God or a moral law (同)transgress, trespass
21. violent and excited activity; "they began to fight like sin" (同)hell
22. estrangement from god (同)sinfulness, wickedness
23. an act that is regarded by theologians as a transgression of Gods will (同)sinning
24. the 21st letter of the Hebrew alphabet
25. of or relating to a cavity or chamber in the body (especially one of the upper chambers of the heart)

PrepTutorEJDIC

1. 《名詞の前に置いて》『一つも』(『一人も,少しも』)・・・『ない』 / 《補語につけて》『決して・・・でない』 / 《省略文で》・・・なし;・・・お断り / 《話》少ししか(あまり)・・・ない / (肯定の問いに対して)『いいえ』;(否定の問いに対して)はい,ええ / 《not, norの前に挿入して》『いや』,否 / 《形容詞の前に置その形容詞を否定して》…どころではない / 《比較級の前に置いて》ちっとも…でない,…と全く同じ / 《… or no の形で》…であってもなくても / 《驚き・困惑・不信などを表して》とんでもない / 《単数形で》『拒否』,「『いいえ』」という返事 / 《複数形で》反対[投]票
2. (承諾・あいさつ・合図などで)『うなずく』,会釈する / (眠くて)『こっくりする』,(油断して)うとうとする《+off》 / 〈草木・穂などが〉揺れる / (承諾・あいさつなどで)〈頭〉‘を'『うなずかせる』 / …‘を'うなずいて示す / 《副詞[句]を伴って》〈人〉‘に'うなずいて示す / 《同意・承諾・あいさつ・命令など,また時には拒絶を表して》(…に対する)『うなずき』,『会釈』《+『to』+『名』》;(眠気による)こっくり
3. (茎・幹の)節(ふし) / (体組織にできた)結節,こぶ(リンパ瘤(りゅう)など) / (天体の軌道の)交点 / (物事の)中心点
4. 〈U〉(宗教・道徳上の)『罪』 / 〈C〉(宗教・道徳上の)『罪の行為』,罪悪 / 〈C〉《特におどけて》違反(過失)の行為 / (宗教・道徳上の)おきてを破る,罪を犯す / (…に)違反(過失)をする,背く《+『against』+『名』》
5. sine

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/01/12 10:37:29」(JST)

wiki en

[Wiki en表示]

Sinoatrial node
Low magnification micrograph of a sinoatrial node (center-right on image) and its surrounding tissue. The SA node surrounds the (sinuatrial) nodal artery (on lumen in the image), a branch of the right coronary artery, abuts cardiac myocytes (of the right atrium) on its deep aspect (left of image) and adipose tissue on its superficial (epicardial) aspect (right of image). H&E stain.
Isolated Heart conduction system, showing SA node
Latin	nodus sinuatrialis
Artery	sinuatrial nodal artery
MeSH	Sinoatrial+Node

The sinoatrial node (also commonly spelled sinuatrial node, abbreviated SA node or SAN, also called the sinus node) is the impulse-generating (pacemaker) tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava. These cells are specialized cardiomyocytes. Though they possess some contractile filaments, they do not contract robustly.

The SAN was first described in 1907 by Arthur Keith and Martin Flack.

Role as a pacemaker

Although all of the heart's cells have the ability to generate the electrical impulses (or action potentials) that trigger cardiac contraction, the sinoatrial node normally initiates it, simply because it generates impulses slightly faster than the other areas with pacemaker potential. Cardiomyocytes, like all muscle cells, have refractory periods following contraction during which additional contractions cannot be triggered; their pacemaker potential is overridden by the sinoatrial or atrioventricular nodes.

In the absence of extrinsic neural and hormonal control, cells in the sinoatrial node (SA node), situated in the upper right corner of the heart, will naturally discharge (create action potentials) at about 60-100 beats/minute. Because the sinoatrial node is responsible for the rest of the heart's electrical activity, it is sometimes called the primary pacemaker.

If the SA node does not function, or the impulse generated in the SA node is blocked before it travels down the electrical conduction system, a group of cells further down the heart will become the heart's pacemaker. These cells form the atrioventricular node (AV node), which is an area between the atria and ventricles, within the atrial septum. If the AV node also fails, Purkinje fibers (or known by some as the bundle of His) are capable of acting as the pacemaker. The reason Purkinje cells do not normally control the heart rate is that they generate action potentials at a lower frequency than the AV or SA nodes.

Histology

High magnification micrograph of sinoatrial node tissue and an adjacent nerve fibre. H&E stain.

The sinoatrial node is submyocardial at the lateral aspect of the junction of the superior vena cava and right atrium. Its deep aspect abuts cardiac myocytes belonging to the right atrium. Its superficial aspect is covered by adipose tissue. The SA node fibres vaguely resemble cardiac myocytes; however, they are measurably thinner, more tortuous and stain less intensely (on H&E) than cardiac myocytes.

Innervation

The SA node is richly innervated by parasympathetic nervous system fibers (CN X: Vagus Nerve) and by sympathetic nervous system fibers (T1-4, Spinal Nerves). This unique anatomical arrangement makes the SA node susceptible to distinctly paired and opposed autonomic influences.

• Stimulation of the vagus nerves (the parasympathetic fibers) causes a decrease in the SA node rate (thereby decreasing the heart rate). Parasympathetic fibers cannot change the force of contraction, however,because they only innervate the SA node and AV node (which control heart rate only)***(NOTE: This statement is not entirely accurate. The following study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2278718/ demonstrates how the parasympathetic nervous system, through the action of vagus nerve, exerts a negative inotropic effect upon the heart)
• Stimulation via sympathetic fibers causes an increase in the SA node rate (thereby increasing the heart rate and force of contraction). Sympathetic fibers can increase the force of contraction because in addition to innervating the SA and AV nodes, they innervate the atria and ventricles themselves.

Blood supply

In the majority of individuals, the SA node receives blood from the right coronary artery, meaning that a myocardial infarction occluding it will cause ischaemia in the SA node unless there is a sufficiently good anastomosis from the left coronary artery. If not, death of the affected cells will stop the SA node from triggering the heartbeat, and pacemaker function will be manifest more distal in the cardiac system (e.g. AV node).

Sinus node dysfunction

Sinus node dysfunction describes an irregular heartbeat caused by faulty electrical signals of the heart. When the heart's sinoatrial node is defective, the heart’s rhythms become abnormal – either too fast, too slow, or a combination.

Additional images

• Heart; conduction system

• Schematic representation of the atrioventricular bundle

See also

• Cardiology
  • Cardiac pacemaker
  • Electrical conduction system of the heart
• Heart block
• Sinus bradycardia
• Sinus tachycardia

References

External links

• sinuatrial+node at eMedicine Dictionary
• SUNY Figs 20:06-01 - "The conduction system of the heart."
• Diagram at gru.net
• thoraxlesson4 at The Anatomy Lesson by Wesley Norman (Georgetown University) (thoraxheartinternalner)
• http://www.healthyheart.nhs.uk/heart_works/heart03.shtml

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. Sick sinus syndrome: Clinical manifestations, diagnosis, and evaluation
• 2. Sick sinus syndrome: Epidemiology, etiology, and natural history
• 3. 洞不全症候群の治療 treatment of the sick sinus syndrome
• 4. 洞房結節の一時停止、停止、および進出ブロック sinoatrial nodal pause arrest and exit block
• 5. Permanent cardiac pacing: Overview of devices and indications

English Journal

• TRPM4 in cardiac electrical activity.

• Guinamard R1, Bouvagnet P2, Hof T1, Liu H3, Simard C1, Sallé L1.
• Cardiovascular research.Cardiovasc Res.2015 Aug 13. pii: cvv213. [Epub ahead of print]
• TRPM4 forms a non-selective cation channel activated by internal Ca2+. Its functional expression was demonstrated in cardiomyocytes of several mammalian species including human but the channel is also present in many other tissues. The recent characterization of the TRPM4 inhibitor 9-phenanthrol and
• PMID 26272755

• Burst pacemaker activity of the sinoatrial node in sodium-calcium exchanger knockout mice.

• Torrente AG1, Zhang R1, Zaini A1, Giani JF2, Kang J1, Lamp ST1, Philipson KD3, Goldhaber JI4.
• Proceedings of the National Academy of Sciences of the United States of America.Proc Natl Acad Sci U S A.2015 Aug 4;112(31):9769-74. doi: 10.1073/pnas.1505670112. Epub 2015 Jul 20.
• In sinoatrial node (SAN) cells, electrogenic sodium-calcium exchange (NCX) is the dominant calcium (Ca) efflux mechanism. However, the role of NCX in the generation of SAN automaticity is controversial. To investigate the contribution of NCX to pacemaking in the SAN, we performed optical voltage map
• PMID 26195795

• Transcription factor ISL1 is essential for pacemaker development and function.

• Liang X, Zhang Q, Cattaneo P, Zhuang S, Gong X, Spann NJ, Jiang C, Cao X, Zhao X, Zhang X, Bu L, Wang G, Chen HS, Zhuang T, Yan J, Geng P, Luo L, Banerjee I, Chen Y, Glass CK, Zambon AC, Chen J, Sun Y, Evans SM.
• The Journal of clinical investigation.J Clin Invest.2015 Aug 3;125(8):3256-68. doi: 10.1172/JCI68257. Epub 2015 Jul 20.
• The sinoatrial node (SAN) maintains a rhythmic heartbeat; therefore, a better understanding of factors that drive SAN development and function is crucial to generation of potential therapies, such as biological pacemakers, for sinus arrhythmias. Here, we determined that the LIM homeodomain transcrip
• PMID 26193633

Japanese Journal

• Autophagy Is Constitutively Active in Normal Mouse Sino-Atrial Nodal Cells

• Omatsu-Kanbe Mariko,Yamamoto Takefumi,Matsuura Hiroshi
• ACTA HISTOCHEMICA ET CYTOCHEMICA 44(5), 223-231, 2011
• … This study was designed to examine the autophagy in sino-atrial (SA) nodal cells from the normal adult mouse heart. … We examined whether the basal level of autophagy in SA nodal cells was different from that in ventricular or atrial myocytes. …
• NAID 130000941524

• Inhomogeneous distribution of action potential characteristics in the rabbit sino-atrial node revealed by voltage imaging

• Masumiya Haruko,Oku Yoshitaka,Okada Yasumasa
• The journal of physiological sciences : JPS 59(3), 227-241, 2009-05-01
• NAID 10025218875

• Creations of biological Pacemaker

• Narazaki Genta,Yamashita Jun K.
• 炎症・再生 : 日本炎症・再生医学会雑誌 = Inflammation and regeneration 29(2), 123-127, 2009-03-25
• NAID 10024797269

Related Links

• Sinoatrial nodeとは - goo Wikipedia (ウィキペディア)

Low magnification micrograph of a sinoatrial node (center-right on image) and its surrounding tissue. The SA node surrounds the (sinuatrial) nodal artery (on lumen in the image), a branch of the right coronary artery, abuts cardiac ...

• Sinoatrial node - definition of sinoatrial node by The Free ...

sinoatrial node n. A small mass of specialized cardiac muscle fibers located in the posterior wall of the right atrium of the heart that acts as a pacemaker by generating at regular intervals the electric impulses of the heartbeat. Also ...

Related Pictures

---

★リンクテーブル★

リンク元	「洞房結節」「SA node」
関連記事	「node」「atrial」「nod」

「洞房結節」

　　[★]

英

sinuatrial node (N,Z), SA node sino-atrial node

同

キース・フラック結節,SA結節、洞結節 sinus node

生理

• ペースメーカーと呼ばれている

• 自動的興奮性を有する
• 房室結節細胞やプルキンエ線維も自動的興奮性を有するが、閾電位に達する前に興奮が伝導してくるので、これらの自動性は潜在的

• 洞房結節の活動電位の発生にはNaチャネルの活性化はほとんど関与しない(授業プリント)

解剖

• 心臓の前外部で上大静脈と右心房の境界部で、心外膜のすぐ下に位置する(M.94)
• 右心房の内面で、上大静脈の開口のすぐ右側にあって、網状の特殊心筋線維からできる小部(KL.294)
• 長さ約25mm、幅2mm (KL.294)
• 洞房結節から特殊心筋線維が心房内に放散し、その筋層に移行している (KL.294)

「SA node」

　　[★]

洞房結節

関

sino-atrial node、sinoatrial node、sinus node

「node」

　　[★]

• n.

• 結節、リンパ節、節、ノード

関

clause、ganglia、ganglion、ganglionic、knot、lymph node、nodal、nodose、nodulate、section、tubercle、tubercular、tuberosity

　 　 　 　 　 　 　 　

「atrial」

　　[★]

• adj.

• 心房性の、心房の

関

atria、atrium、heart atria、heart atrium

　

「nod」

　　[★]