Heavy bleeding after childbirth (postpartum haemorrhage) Heavy bleeding after childbirth is also known as postpartum haemorrhage (PPH), and is an emergency complication of childbirth. Postpartum haemorrhage is defined as a loss of 500ml or more blood from the genital tract in the first 24 hours after giving birth.
The afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems.They play an important role in the regulation of blood pressure as a part of the tubuloglomerular feedback mechanism.he afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems.
An arteriole /ÉrËtÉªÉri.oÊl/ is a small diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries. Arterioles have muscular walls (usually only one to two layers of smooth muscle) and are the primary site of vascular resistance. The greatest change in blood pressure and velocity of blood flow occurs at the transition of arterioles to capillaries. The decreased velocity of flow in the capillaries reduces the pressure and increases exchange of gas and nutrients. Arterioles receive autonomic nervous system innervation and respond to various circulating hormones in order to regulate their diameter. Retinal vessels lack a functional sympathetic innervation.