See Also: pityriasis nigra(medicine)
Nigra(medicine)
nigra(dictionary)
Linea nigra(health)
tinea nigra(medicine)
cataracta nigra(medicine)
substantia nigra(medicine)
seborrhoea nigra(medicine)
cardiopathia nigra(medicine)
Substantia nigra(health)

Fetal circulation (health) and pityriasis nigra (medicine)


Fetal circulation (health)


The blood circulation in the fetus before birth. Before birth, the blood from the heart headed for the lungs in the aptly named pulmonary artery is shunted away from the lungs and returned to the greatest of arteries, the aorta. This arterial shunting occurs through a short vessel called the ductus arteriosus. When the shunt is open, it is said to be patent (pronounced p?tent). The ductus arteriosus usually tourniquets itself off at or shortly after birth. After closure of the ductus, blood is permitted from that time on to course freely to the lungs. Sometimes, however, the patent ductus arteriosus (PDA) persists and simply will not close by itself. Surgery is then done to ligate (tie off) the ductus. PDA ligation is a closed-heart operation. Historically, it was one of the earliest surgical procedures performed in children with cardiovascular disease.





pityriasis nigra (medicine)


pityriasis nigra -->
tinea nigra


A fungus infection due to Exophiala werneckii, marked by dark lesions giving a spattered appearance and occurring most commonly on the palms of the hands.

Synonym: pityriasis nigra.