The Toxicologist's Pocket Handbook

Glossary—by Subject 311Estrus: Phase of the sexual cycle of female mammals characterized by willingnessto mate.Exencephaly: Brain outside of the skull as a result of a large cranial defect.Exomphalos: Congenital herniation of abdominal viscera into umbilical cord.Exophthalmos: Protrusion of the eyeball (“pop” eye).Fecundity: Ability to produce offspring rapidly and in large numbers.Feticide: The destruction of the fetus in the uterus.Gamete: A male (spermatozoa) or female (ovum) reproductive cell.Gastroschisis: Fissure of the abdominal wall (median line) not involving theumbilicus, usually accompanied by protrusion of the small part of the largeintestine, not covered by membranous sac.Hemivertebra: Presence of only one-half of a vertebral body.Hepatic lobe agenesis: Absence of a lobe of the liver.Hepatomegaly: Abnormal enlargement of the liver.Hydrocephaly: Enlargement of the head caused by abnormal accumulation ofcerebrospinal fluid in subarachnoid cavity (external hydrocephaly) or ventricularsystem (internal hydrocephaly).Hydronephrosis: Dilatation of the renal pelvis usually combined with destructionof renal parenchyma and often with dilation of the ureters (bilateral,unilateral). Note: This is a pathology term and should have histologicalconfirmation.Hypoplasia of the lung: Bronchial tree is poorly developed, and pulmonarytissue shows an abnormal histologic picture (total or partial); incompletedevelopment, smaller.Hypospadias: Urethra opening on the underside of the penis or on the perineum(males), or into the vagina (females).Imperforate: Not open; abnormally closed.Incomplete ossification (delayed, retarded): Extent of ossification is lessthan what would be expected for that developmental age, not necessarilyassociated with reduced fetal or pup weight.Levocardia: Displacement of the heart in the extreme left hemithorax.Lordosis: Anterior concavity in the curvature of the cervical and lumbar spineas viewed from the side.Macrobrachia: Abnormal size or length of the arm.Macrodactylia: Excessive size of one or more digits.