Dictionary

plaque, skin A broad, raised area on the skin. A skin plaque is broader than it is high.

plaque 1 The white, semihardened substance that forms on the teeth as a result of bacterial action on food particles and provides an ideal environment for dental caries (cavities). 2 A semihardened accumulation of substances, including cholesterol, on the inner walls of blood vessels that can lead to blood clot formation, heart attacks, and strokes….

plantar response See Babinski reflex.

plantar Having to do with the sole of the foot.

plague, sylvatic A type of plague that is spread by ground squirrels and other wild rodents. Sylvatic plague is sometimes seen in the western portion of the US.

plague An infectious disease that is caused by the bacterium Yersinia pestis, which mainly infects rats and other rodents. Fleas function as the prime vectors for carrying Y. pestis from one species to another. Transmission of the plague to people can also occur if people eat infected animals, such as squirrels. When someone has the…

placental stage of labor The part of labor that lasts from the birth of the baby until the placenta and fetal membranes are delivered. Also known as third stage of labor.

placental dystocia Difficulty in delivering the placenta. A number of techniques may be tried to overcome placental dystocia, including changing position, massage, nursing the newborn baby to induce uterine contractions, and in some cases using medications that induce uterine contractions.

placental chorioangioma A benign vascular (blood vessel) tumor of the placenta. Large chorioangiomas can cause complications, including excess amniotic fluid (polyhydramnios), maternal and fetal clotting problems (coagulopathies), premature delivery, toxemia, fetal heart failure, and hydrops (excess fluid) that affect the fetus.

placenta previa A condition in which the placenta is implanted near the outlet of the uterus, so that at the time of delivery the placenta precedes the baby. Placenta previa can cause painless bleeding in the last trimester of pregnancy, and it may be a reason to perform a C-section. Also known as low placenta.

placenta percreta A condition in which the placenta invades the uterine wall. In placenta percreta, the vascular processes of the chorion (chorionic villi), a fetal membrane that enters into the formation of the placenta, can invade the full thickness of the myometrium. This can cause an incomplete rupture of the uterus. The chorionic villi can…

placenta accreta The abnormal adherence of the chorion of the placenta to the myometrium of the uterus. Normally there is tissue intervening between the chorionic villi and the myometrium, but in placenta accreta, the vascular processes of the chorion grow directly in the myometrium. Placenta accreta can progress into placenta percreta.