Which of the following arteries supplying uterus is insensitive to hormonal changes
**Core Concept**
The uterine arteries undergo significant physiological changes during the menstrual cycle and pregnancy, primarily in response to estrogen and progesterone levels. This is crucial for maintaining uterine blood flow and ensuring a healthy pregnancy.
**Why the Correct Answer is Right**
The uterine arteries are primarily regulated by estrogen and progesterone, leading to changes in their diameter and blood flow. However, there is one artery that remains relatively unaffected by these hormonal fluctuations. The internal iliac artery, which supplies the uterine arteries, has a rich sympathetic innervation that helps maintain its tone and blood flow, making it less sensitive to hormonal changes.
**Why Each Wrong Option is Incorrect**
**Option A:** The uterine artery itself is highly sensitive to hormonal changes, making this option incorrect.
**Option B:** The ovarian arteries, which supply the ovaries, are also sensitive to hormonal changes, particularly in response to estrogen and progesterone levels.
**Option C:** The middle cerebral artery, which supplies the brain, is not related to the uterine supply and is not affected by hormonal changes.
**Clinical Pearl / High-Yield Fact**
The uterine arteries undergo significant remodeling during pregnancy to increase blood flow and ensure a healthy placenta. This is mediated by estrogen and progesterone, which stimulate the production of growth factors and angiogenic factors.
**Correct Answer:** B. The internal iliac artery supplies the uterine arteries but is relatively insensitive to hormonal changes.