psychomotor behavior
The specific behavior of an organism that combines cognitive functions and physical movement. For example, driving a car, throwing a ball, or playing a musical instrument.
blastocyst development
The process whose specific outcome is the progression of the blastocyst over time, from its formation to the mature structure. The mammalian blastocyst is a hollow ball of cells containing two cell types, the inner cell mass and the trophectoderm.
nematosome
Cytoplasmic, ball-like inclusion resembling a nucleolus and consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix. It measures approximately 0.9 microns and lacks a limiting membrane. Its strands (diameter = 400-600 A) appear to be made of an entanglement of tightly packed filaments and particles approximately 25-50 A thick. Cytochemical studies suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles.