Symptoms include: 1  excessive fatigue and exhaustion. 2  non-refreshing sleep (you get sufficient hours of sleep, but wake fatigued) 3  overwhelmed by or unable to cope with stressors. 4  feeling rundown or overwhelmed. 5  craving salty and sweet foods. 6  you feel most energetic in the evening.
The blastocyst is the second major stage of development, after the morula, for a newly fertilized individual once cell division has begun. Cells begin to differentiate, or become specialized, and have moved on to an outer/inner arrangement: the outer cells are called the trophoblast which will give rise to the placenta, and the inner are called the embryoblast (or inner cell mass) as they will give rise to the embryo.
The outer layer of the blastocyst consists of cells collectively called the trophoblast. This layer surrounds the inner cell mass and a fluid-filled cavity known as the blastocoele.