The continent can be broken into four major landform regions: the Coastal Plains, the Eastern Highlands, the Central Lowlands and the Western Plateau. These landform regions have been created by movements in the Earth's crust, river erosion and changes in climate and sea level.
Causes of Low HGB and Low HCT. Figuring out hematocrit levels in the blood is done through Mean Corpuscular Volume or MCV and Red Cell Distribution Width or RDW. These tests determine whether someone is suffering from low Hgb and/or low HCT levels in their blood and can help doctors determine a cause. 1.Anemia is the direct result of a low red blood cell count.iguring out hematocrit levels in the blood is done through Mean Corpuscular Volume or MCV and Red Cell Distribution Width or RDW. These tests determine whether someone is suffering from low Hgb and/or low HCT levels in their blood and can help doctors determine a cause.
HCG is the hormone that  pregnancy tests  detect. HCG increases to a peak at around 12 weeks. It has mild thyroid stimulating effects and, as a result, can cause some symptoms of hyperthyroidism. HCG is in part responsible for the nausea during the first trimester. In situations of multiple pregnancies (twins, triplets) HCG levels are even higher, and symptoms can be more pronounced. Temporary subclinical (no apparent symptoms) hyperthyroidism occurs in 10-20% of normal pregnant women during this period, and these women typically do not require treatment.