Spiral arteries are small arteries which temporarily supply blood to the

endometrium The endometrium is the inner epithelium, epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The funct ...

of the

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

during the

luteal phase The menstrual cycle is on average 28 days in length. It begins with Menstruation, menses (day 1–7) during the follicular phase (day 1–14), followed by ovulation (day 14) and ending with the luteal phase (day 14–28). While historically, medi ...

of the

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that makes pregnancy possible. The ovarian cycle controls the production and release of eg ...

. In

histology Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

, identifying the presence of these arteries is one of the most useful techniques in identifying the phase of the cycle. The spiral arteries are converted for uteroplacental blood flow during pregnancy, involving: * Loss of smooth muscle and elastic lamina from the vessel wall. * 5-10 fold dilation at the mouth of the vessel. Failure of the physiological conversion of the spiral arteries can cause a number of complications, including

intrauterine growth restriction Intrauterine growth restriction (IUGR), or fetal growth restriction, is the poor growth of a fetus while in the womb during pregnancy. IUGR is defined by clinical features of malnutrition and evidence of reduced growth regardless of an infant's ...

and

pre-eclampsia Pre-eclampsia is a multi-system disorder specific to pregnancy, characterized by the new onset of hypertension, high blood pressure and often a significant amount of proteinuria, protein in the urine or by the new onset of high blood pressure a ...

References

Arteries of the abdomen articles {{circulatory-stub