Human skin color is determined by the interaction of melanin, carotene and hemoglobin. Storage of water, fat, glucose and vitamin D is also a function of the integumentary system, according to the AAD.
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The aPTT is considered a more sensitive version of the PTT and is used to monitor the patientâs response to heparin therapy. The reference range of the aPTT is 30-40 seconds. The reference range of the PTT is 60-70 seconds.