کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3432563 1594903 2015 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Why the heart is like an orchestra and the uterus is like a soccer crowd
ترجمه فارسی عنوان
چرا قلب مثل یک ارکستر است و رحم یک جمعیت فوتبال است
کلمات کلیدی
رفتار فوق العاده ای مکانیک انتقال، بارداری، هماهنگ سازی رحم
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی پزشکی و دندانپزشکی (عمومی)
چکیده انگلیسی

The human uterus has no pacemaker or motor innervation, yet develops rhythmic, powerful contractions that increase intrauterine pressure to dilate the cervix and force the fetus through the pelvis. To achieve the synchronous contractions required for labor, the muscle cells of the uterus act as independent oscillators that become increasingly coupled by gap junctions toward the end of pregnancy. The oscillations are facilitated by changes in resting membrane potential that occur as pregnancy progresses. Reductions of potassium channels in the myocyte membranes in late pregnancy prolong myocyte action potentials, further facilitating transmission of signals and recruitment of neighboring myocytes. Late in pregnancy prostaglandin production increases leading to increased myocyte excitability. Also late in pregnancy myocyte actin polymerizes allowing actin-myosin interactions that generate force, following myocyte depolarization, calcium entry, and activation of myosin kinase. Labor occurs as a consequence of the combination of increased myocyte to myocyte connectivity, increased depolarizations that last longer, and activated intracellular contractile machinery. During labor the synchronous contractions of muscle cells raise intrauterine pressure to dilate the cervix in a process distinct from peristalsis. The synchronous contractions occur in a progressively larger region of the uterine wall. As the size of the region increases with increasing connectivity, the contraction of that larger area leads to an increase in intrauterine pressure. The resulting increased wall tension causes myocyte depolarization in other parts of the uterus, generating widespread synchronous activity and increased force as more linked regions are recruited into the contraction. The emergent behavior of the uterus has parallels in the behavior of crowds at soccer matches that sing together without a conductor. This contrasts with the behavior of the heart where sequential contractions are regulated by a pacemaker in a similar way to the actions of a conductor and an orchestra.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: American Journal of Obstetrics and Gynecology - Volume 213, Issue 2, August 2015, Pages 181–185
نویسندگان
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