Passage
Endometriosis is a chronic, treatable disease of the female reproductive tract associated with infertility and pelvic pain in women of reproductive age. The endometrium, a layer of epithelial tissue that grows and sheds during the menstrual cycle, normally makes up the interior lining of the uterus. In individuals with endometriosis, endometrial tissue is also found ectopically (outside the uterine cavity) .The mechanism by which endometrial tissue successfully implants outside the uterine cavity is thought to be dependent on signaling molecules that promote the formation of blood vessels locally. One of these signaling molecules is vascular endothelial growth factor (VEGF) , a protein that is normally synthesized and secreted by various tissues in response to reduced oxygen levels. Because VEGF is thought to be implicated in ectopic endometrial tissue growth, researchers hypothesize that the abdominal and pelvic structures of women with endometriosis would contain higher levels of VEGF compared to women without endometriosis.In an experiment, women ages 25-40 were divided into groups based on endometriosis disease status. Individuals on any type of medication were excluded from the study. Using minimally invasive surgery, samples of peritoneal fluid were taken from healthy subjects (n = 19) and from subjects diagnosed with endometriosis (n = 30) . An enzyme-linked immunosorbent assay (ELISA) was used to characterize the concentration of VEGF protein present within these samples.In a separate procedure that took place five days after peritoneal fluid collection, uterine endometrial samples were obtained from all subjects and visualized under a microscope to determine the menstrual cycle phase of each participant. Figure 1 shows the level of VEGF in the abdominal fluid categorized by disease status and menstrual cycle phase.
Figure 1 VEGF concentration in sampled peritoneal fluid (Note: * = p < 0.05; Proliferative phase = stage immediately preceding ovulation; Secretory phase = stage immediately following ovulation)
-VEGF signaling also leads to the dilation of existing blood vessels. One function of vasodilation is to:

Question

Passage
Endometriosis is a chronic, treatable disease of the female reproductive tract associated with infertility and pelvic pain in women of reproductive age. The endometrium, a layer of epithelial tissue that grows and sheds during the menstrual cycle, normally makes up the interior lining of the uterus. In individuals with endometriosis, endometrial tissue is also found ectopically (outside the uterine cavity) .The mechanism by which endometrial tissue successfully implants outside the uterine cavity is thought to be dependent on signaling molecules that promote the formation of blood vessels locally. One of these signaling molecules is vascular endothelial growth factor (VEGF) , a protein that is normally synthesized and secreted by various tissues in response to reduced oxygen levels. Because VEGF is thought to be implicated in ectopic endometrial tissue growth, researchers hypothesize that the abdominal and pelvic structures of women with endometriosis would contain higher levels of VEGF compared to women without endometriosis.In an experiment, women ages 25-40 were divided into groups based on endometriosis disease status. Individuals on any type of medication were excluded from the study. Using minimally invasive surgery, samples of peritoneal fluid were taken from healthy subjects (n = 19) and from subjects diagnosed with endometriosis (n = 30) . An enzyme-linked immunosorbent assay (ELISA) was used to characterize the concentration of VEGF protein present within these samples.In a separate procedure that took place five days after peritoneal fluid collection, uterine endometrial samples were obtained from all subjects and visualized under a microscope to determine the menstrual cycle phase of each participant. Figure 1 shows the level of VEGF in the abdominal fluid categorized by disease status and menstrual cycle phase.

Figure 1 VEGF concentration in sampled peritoneal fluid (Note: * = p < 0.05; Proliferative phase = stage immediately preceding ovulation; Secretory phase = stage immediately following ovulation)
-VEGF signaling also leads to the dilation of existing blood vessels. One function of vasodilation is to:

Quizplus · Accepted Answer

11ecba2d_1003_c572_a3bf_0d22ad3a23b9_MD0008_00 Blood vessels are tubular channels that transport blood throughout the body. Many vessels are surrounded by smooth muscle, which contracts to facilitate narrowing or relaxes to promote widening of the blood vessels in response to neural and hormonal inputs. Narrowing of the blood vessels (decreased diameter) is known as vasoconstriction. Vasoconstriction reduces blood vessel volume, resulting in increased blood pressure (BP; the pressure of blood against vessel walls). Consequently, vasoconstriction functions to maintain BP following sudden blood pressure drops (eg, following fluid loss). Vasoconstriction also reduces blood flow (the volume of blood travelling through a vessel per unit time), and can therefore redirect blood flow to other tissues. In contrast, widening of the blood vessels (increased diameter) is known as vasodilation. Vasodilation increases blood vessel volume and decreases BP. Vasodilation also increases blood flow to promote the delivery of oxygen and nutrients to tissues supplied by that blood vessel. For example, during exercise muscle activity is enabled as blood vessels supplying skeletal muscles dilate. Likewise, digestion is promoted as blood vessels supplying the abdominal organs dilate following a meal. (Choice A) When body temperature is higher than normal (eg, in warm environments), blood vessels supplying the skin vasodilate to facilitate blood flow to the body surface, promoting heat loss through the skin and decreasing body temperature. However, when body temperature is lower than normal (eg, in cold environments), blood vessels supplying the skin vasoconstrict to limit the amount of blood reaching the body surface, limiting heat loss to the environment and increasing body temperature. (Choice C) Vasodilation of renal blood vessels increases blood flow to the kidney and consequently increases the glomerular filtration rate (amount of blood filtered per unit time). This leads to increased urine output and decreased blood volume, worsening dehydration. (Choice D) Vasodilation following fluid loss further decreases BP. Educational objective: Vasodilation (blood vessel widening) decreases blood pressure and increases blood flow to the tissues supplied by that blood vessel. Vasoconstriction (blood vessel narrowing) increases blood pressure and decreases blood flow to the tissues supplied by that blood vessel.