After the heart stops beating, do the red and white blood cells and the other cellular elements in the blood become non-functional immediately? Or does it take time? Would clotting occur after death?
1$\begingroup$ Not immediately, but clotting will happen within a matter of minutes. When I do blood draws from cardiac puncture in mice, the blood in the heart is coagulated enough that I cannot get a draw within about 10min. $\endgroup$– The NightmanSep 15, 2015 at 0:18
I don't exactly know what you meant to say by "non-functional".
- Red blood cells are delivering oxygen to tissues, but they cannot do this anymore in the lack of blood flow.
- White blood cells degenerate and after about 84 hours are no longer existing as cells (Babapulle CJ, Jayasundera NP, 1993). Neutrophiles degenerate first and lymphocytes last.
- Platelets follow an apparent increase in number due to hypostatic phenomena (Thomsen H et al, 1999). Then thrombolytic activity is increased and platelet-platelet aggregates form. Some also adhere to fibrinogen and erythrocytes.
Overall, due to increase of acidic metabolites concentration, the pH of the blood decreases. It takes about 20 hours to reach a blood pH of 5.5 (Andrea E. Donaldson and Iain L. Lamont, 2013)
- Babapulle CJ, Jayasundera NP. Cellular changes and time since death. Med Sci Law. 1993 Jul;33(3):213-22.
- Thomsen H, Kaatsch HJ, Krisch B. How and why does the platelet count in postmortem blood change during the early postmortem interval? Forensic Sci Int. 1999 May 17;101(3):185-94.
- Andrea E. Donaldson, Iain L. Lamont. Biochemistry Changes That Occur after Death: Potential Markers for Determining Post-Mortem Interval. PLoS One. 2013; 8(11): e82011. doi: 10.1371/journal.pone.0082011