the different mechanisms of action potential propagation in the heart

نویسندگان

s mahdavi

m rezaei-tavirani

f towhidkhah

sh gharibzadeh

چکیده

it was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (ap). it seems that some other types of mechanisms must be involved in ap propagation. in this article, we study the different suggested mechanisms of ap propagation. we have calculated different conduction routes and hypothesized novel viewpoints on the mechanisms of conduction in myocyte. it seems that electric field and gap junctions are the main routes for propagation of action potential, but they are affected in different phases of action potential. gap junction has a dynamic behavior in each cardiac cycle, managing different routes of propagation in the diverse moments. gap junctions could be open in phases 0, 1, 3 and 4 and close in phase 2 (plateau) of action potential. whenever gap junction is open, conduction can be fulfilled rapidly by current flow and whenever it is closed, the electrical field will be the main route of propagation. this view on ap propagation may be useful for better exploitation of drugs or designing new remedies in arrhythmias and diseases that cause diminished cardiac contractility such as cardiac failure.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The Different Mechanisms of Action Potential Propagation in the Heart

It was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. Some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (AP). It seems that some other types of mechanisms must be involved in AP propagation. In this article, we...

متن کامل

The Different Mechanisms of Action Potential Propagation in the Heart

It was thought previously that cardiac muscle gap junctions provide low-resistance connections between cells and permit the local-circuit current to flow. Some evidences show that myocardial cells may not require low-resistance connections for successful propagation of the action potential (AP). It seems that some other types of mechanisms must be involved in AP propagation. In this article, we...

متن کامل

romantic education:reading william wordsworths the prelude in the light of the history of ideas

عصر روشنگری زمان شکل گیری ایده های مدرن تربیتی- آموزشی بود اما تاکید بیش از اندازه ی دوشاخه مهم فلسفی زمان یعنی عقل گرایی و حس گرایی بر دقت و وضوح، انسان عصر روشنگری را نسبت به دیگر تواناییهایش نابینا کرده و موجب به وجود آمدن افرادی تک بعدی شد که افتخارعقلانیتشان، تاکید شان بر تجربه فردی، به مبارزه طلبیدن منطق نیاکانشان وافسون زدایی شان از دنیا وتمام آنچه با حواس پنجگانه قابل درک نبوده و یا در ...

the analysis of the role of the speech acts theory in translating and dubbing hollywood films

از محوری ترین اثراتی که یک فیلم سینمایی ایجاد می کند دیالوگ هایی است که هنرپیش گان فیلم میگویند. به زعم یک فیلم ساز, یک شیوه متأثر نمودن مخاطب از اثر منظوره نیروی گفتارهای گوینده, مثل نیروی عاطفی, ترس آور, غم انگیز, هیجان انگیز و غیره, است. این مطالعه به بررسی این مسأله مبادرت کرده است که آیا نیروی فراگفتاری هنرپیش گان به مثابه ی اعمال گفتاری در پنج فیلم هالیوودی در نسخه های دوبله شده باز تولید...

15 صفحه اول

the effect of task cognitive complexity and time limit on the performance of the learners with different proficiency levels in second language writing skill

this study investigated the effects of manipulating the cognitive complexity of tasks along +/- few elements and the time limits on l2 learners writing performance. to conduct the study, 60 iranian efl learners with two levels of proficiency, low and high intermediate, were selected and assigned to three groups based on the time devoted to task completion. the participants performed both a simp...

15 صفحه اول

the effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
iranian journal of pharmaceutical research

جلد ۲۰۰۷، شماره ۱، صفحات ۵۱-۵۶

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023