Early Development, Devel. Physiol., Dr. D. Penney
Table 2.06 - Some Human Heart Facts from a Cellular Point of View:
DNA: Concentration highest at birth, decreases with growth.
At birth - 1/2 in muscle cells, 1/2 in fibroendothelial cell nuclei.
By childhood - 2/5 in muscle cells, 3/5 in fibroendothelial cell nuclei
Adult - less than 1/3 in myocytes, 2/3 in fibroendothelial cell nuclei
Cell Numbers: Myocyte nuclei double in LV after birth; also in RV but occurs a little later.
Myocyte numbers in human heart 2,000,000,000; at birth 7-9000,000,000, and in childhood 1- 2,000,000,000.
There are an equal number of fibroblasts at birth, later 4-6,000,000,000.
Capillary Density: 4,000 per mm2 in infants, 3,342 per mm2 in adults
Faster proliferation of capillaries relative to myocytes occurs during postnatal development
Mean intercapillary distance decreases from 31-18 um.
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