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.
Composed of a thick muscular wall, arterioles actively constrict and relax by means of myogenic, hormonal, and pharmacological mechanisms (19, 21). As the major vascular component that controls peripheral resistance, the arterioles are distinct from conduit arteries. The composition of arterioles is not dominated by collagen but by smooth muscle (7, 9), which makes up two thirds of arteriolar wall volume and determines the overall mechanical behavior. Collagen, which typically composes half of the volume of large arteries, has a negligible volume density in arteriolar composition (37). The composition of arteriolar walls has hardly been reported with the exception of the composition of rat cerebral pial arterioles, which have been extensively studied by