Another meaning mentioned for alaqah in classical commentaries is “blood clot” or “similar to a blood clot”. The meaning of “a blood clot” accurately reflects the external appearance of the embryo and its sacs for at this stage blood forms in the blood vessels in the form of isolated islands. The blood, though fluid, does not circulate until the end of the third week. The heart joins with blood vessels in the embryo, connecting stalk, chorion, and umbilical vesicle to form a primitive cardiovascular system.
Figure 4 Diagram of the embryonic cardiovascular system during the fourth week (approximately 26 days), viewed from the left side during the ʿalaqah stage. The external appearance of the embryo and its sacs is similar to that of a blood clot, due to the presence of relatively large amounts of blood present in the embryo and the chorion. The umbilical vein carries well-oxygenated blood and nutrients from the chorionic sac to the embryo. The umbilical arteries carry poorly oxygenated blood and waste products from the embryo to the chorionic sac. (From Moore and Persaud (2007)).
By the end of the third week the blood starts to circulate and the heart begins to beat at 22 to 23 days (Figure 4). Although the embryo’s blood is fluid 10, it nevertheless takes on the appearance of a blood clot (see Figure 4 and Figure 5) 11. These features incorporate the meanings of “a blood clot” and “wet blood” for alaqah as given above.
9 For animated video footage of the embryo at this stage see http://web.tt.se/lennart_nilsson_video/video9.html and http://web.tt.se/lennart_nilsson_video/video10.html (accessed 22 December 2013). Footage by Lennart Nilsson.
10 “The blood is kept from clotting by an anticoagulant produced by the chorion ” Sherwood and Learning (2011, p. 778) “It secretes some anticoagulant substance which prevents coagulation of blood in the intervillous space ” Daftary and Chakravarty (2011)
11 An implanted blastocyst would also resemble a blood clot: “Implantation begins at about the 6th to 7th day after fertilization. The part of the blastocyst projecting into the uterine cavity remains relatively thin. The syntrophoblast contains a proteolytic enzyme which causes destruction of the endometrial cells so that that the blastocyst sinks deeper and deeper into the uterine mucosa…The final deficiency in the endometrium is sealed off by a blood or fibrin clot, overlying the blastocyst. This cover is called the operculum. By about 10 to 12 days after fertilization, the blastocyst is completely encased in the endometrium and thus, implantation is complete.” Allan and Kramer (2010, p. 23).
Figure 5 Embryo in the fourth week (about 22-24 days) shows the clear rudiments of brain and backbone. Its heart pumps blood to the liver and into the aorta. (A Child is Born, Lennart Nilsson, 1990, p. 79). The meaning of “a blood clot” describes the most prominent internal structure that affects the external appearance, for in the ʿalaqah stage, blood forms in the blood vessels in the form of isolated islands. The vessels resemble coagulated blood since the blood is circulating very slowly.
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| Figur 4 |
Figure 4 Diagram of the embryonic cardiovascular system during the fourth week (approximately 26 days), viewed from the left side during the ʿalaqah stage. The external appearance of the embryo and its sacs is similar to that of a blood clot, due to the presence of relatively large amounts of blood present in the embryo and the chorion. The umbilical vein carries well-oxygenated blood and nutrients from the chorionic sac to the embryo. The umbilical arteries carry poorly oxygenated blood and waste products from the embryo to the chorionic sac. (From Moore and Persaud (2007)).
By the end of the third week the blood starts to circulate and the heart begins to beat at 22 to 23 days (Figure 4). Although the embryo’s blood is fluid 10, it nevertheless takes on the appearance of a blood clot (see Figure 4 and Figure 5) 11. These features incorporate the meanings of “a blood clot” and “wet blood” for alaqah as given above.
9 For animated video footage of the embryo at this stage see http://web.tt.se/lennart_nilsson_video/video9.html and http://web.tt.se/lennart_nilsson_video/video10.html (accessed 22 December 2013). Footage by Lennart Nilsson.
10 “The blood is kept from clotting by an anticoagulant produced by the chorion ” Sherwood and Learning (2011, p. 778) “It secretes some anticoagulant substance which prevents coagulation of blood in the intervillous space ” Daftary and Chakravarty (2011)
11 An implanted blastocyst would also resemble a blood clot: “Implantation begins at about the 6th to 7th day after fertilization. The part of the blastocyst projecting into the uterine cavity remains relatively thin. The syntrophoblast contains a proteolytic enzyme which causes destruction of the endometrial cells so that that the blastocyst sinks deeper and deeper into the uterine mucosa…The final deficiency in the endometrium is sealed off by a blood or fibrin clot, overlying the blastocyst. This cover is called the operculum. By about 10 to 12 days after fertilization, the blastocyst is completely encased in the endometrium and thus, implantation is complete.” Allan and Kramer (2010, p. 23).
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| Figure 5 |
Figure 5 Embryo in the fourth week (about 22-24 days) shows the clear rudiments of brain and backbone. Its heart pumps blood to the liver and into the aorta. (A Child is Born, Lennart Nilsson, 1990, p. 79). The meaning of “a blood clot” describes the most prominent internal structure that affects the external appearance, for in the ʿalaqah stage, blood forms in the blood vessels in the form of isolated islands. The vessels resemble coagulated blood since the blood is circulating very slowly.
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