tropho-, troph-, -trophy, -trophs, -trophically, -trophic, -trophous
(Greek: food, nutrition, nourishment; development)
Don't confuse this tropho-, -trophy element with tropo-, meaning "turn, turning," etc.
2. Defective nutrition of hair, often culminating in alopecia. May be acquired or congenital; the latter often with metabolic or other birth defects.
This condition is associated with failure to thrive in life, physical and mental retardation, and progressive severe deterioration of the brain; apparently a defect of copper transport.
The sulfur content of the hair is greatly reduced and mental retardation has frequently been a related feature.2. Congenital fragile hair with multiple fractures resulting from low sulfur-containing amino acid, cysteine, content of the hair, mental impairment, and short stature.
2. Relating to or dependent upon nutrition.
In mammals, a layer of tissue formed by cells forming the outer covering of the blastocyst. After implanation of the blastocyst, this layer is no longer cellular. At the 5th-5th day of human pregnancy, the blastocyst attaches to the luteinized endometrium and differentiates on its surface a syncytium which helps to penetrate the epithelium and then break through into the maternal mucous membrane (implanation).
As early as implanation (about the 8th-9th day), the trophoblast starts to establish a fetal-maternal exchange of gases and nutriments. When the blastocyst has completely penetrated into the maternal mucosa, the trophoblast consists of an external syncytial layer around the blastocyst, the syncytiotrophoblast, and an internal cellular layer, the cytotrophoblast.