1. Any simple separation of normally joined parts. SYN: divarication. 2. The mid-portion of diastole when the blood enters the ventricle slowly or ceases to enter prior to atrial systole. D. duration is in inverse proportion to heart rate and is absent at very high heart rates. [G. a separation]
- d. recti separation of rectus abdominis muscles away from the midline, sometimes seen during or following pregnancy.
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1) an abnormal separation of parts normally joined together
2) the rest phase of cardiac diastole occurring between filling of the ventricle and the start of atrial contraction
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di·as·ta·sis (di-asґtə-sis) [Gr. “separationâ€] 1. a form of dislocation in which there is separation of two bones normally attached to each other without the existence of a true joint; as in separation of the pubic symphysis. Also, separation beyond the normal between associated bones, as between the ribs, or the ulna and radius. 2. a relatively quiescent period of slow ventricular filling during the cardiac cycle; it occurs in mid-diastole, following the rapid filling phase and just prior to atrial systole. See illustration at cardiac cycle, under cycle.Medical dictionary. 2011.