Placenta is generally characterized on the basis of the degree of coverage to the internal os that are as given below:
Total placenta previa, in this the the placenta covers the cervical os where as the partial placenta previa the internal os is covered partially by the placenta.
Marginal placenta is present on the margin or edge of cervical os and in low lying it is present near but not reach it.
In humans, the brain accounts for ~2% of the body weight, but it consumes ~20% of glucose-derived energy making it the main consumer of glucose (~5.6 mg glucose per 100 g human brain tissue per minute.
