implantation

process by which a blastocyst embeds itself in the uterine endometrium

incomplete dominance

pattern of inheritance in which a heterozygous genotype expresses a phenotype intermediate between dominant and recessive phenotypes

inner cell mass

cluster of cells within the blastocyst that is fated to become the embryo

involution

postpartum shrinkage of the uterus back to its pre-pregnancy volume

inguinal canal

opening in abdominal wall that connects the testes to the abdominal cavity

isthmus

narrow, medial portion of the uterine tube that joins the uterus

infundibulum

(of the uterine tube) wide, distal portion of the uterine tube terminating in fimbriae