At the level of the iliac tubercle, a bony prominence on the lateral aspect of the crest 5 cm posterior to the anterior superior iliac spine, the FL is preferentially thickened and this represents the origin of the ITB.
The highest layer of earths atmosphere is the exosphere. The inner core has the most or highest amount of density (iron/nickel). I think its the core of the Earth with highest temperature with  6000 degree Celsius. The crust is the layer of the Earth that has the the lowest density. It depends a bit on what you consider being a part.
Let's review. The Earth's mantle is the thickest layer of the planet and accounts for about 84% of the Earth's volume and 67% of its mass. It lies between the crust and the core. The Earth's mantle is never very far away from us; much closer than the Moon, for instance. But, it's truly an alien environment down there, a realm of extreme temperatures and pressures where rock undergoes convection like boiling water in a kettle.