The uteroplacental circulation starts with the maternal blood flow into the intervillous space through decidual spiral arteries.
Exchange of oxygen and nutrients take place as the maternal blood flows around terminal villi in the intervillous space. The in-flowing maternal arterial blood pushes deoxygenated blood into the endometrial and then uterine veins back to the maternal circulation.
The fetal-placental circulation allows the umbilical arteries to carry deoxygenated and nutrient-depleted fetal blood from the fetus to the villous core fetal vessels. After the exchange of oxygen and nutrients, the umbilical vein carries fresh oxygenated and nutrient-rich blood circulating. Leandro, There are two types of vessels, arteries and veins. Arteries are brighter, since they transport blood rich in oxygen to the organs of the body. The veins afterwards transport the blood, which is at low oxygen level and thus darker, to the lungs and the liver.
For many medical applications it would be of great benefit, if the vessels could be distinguished into arteries and veins, since there are many diseases with one symptom being an abnormal ratio of the size of arteries to veins.
For example in diabetic patients the veins are abnormally wide, while diseases of the pancreas lead to narrowed arteries and high blood pressure results in thickened arteries. To detect these diseases the retina is routinely examined. An artery is a vessel that carries blood away from the heart and toward other tissues and organs. Arteries are part of the circulatory system, which delivers oxygen and nutrients to every cell of the body.
Veins are the blood vessels that carry deoxygenated blood from parts of our body back to the heart. The blood from the heart is carried through the body by a complex network of blood vessels. Arteries take blood away from the heart. The main artery is the aorta that branches into other major arteries, which take blood to different limbs and organs.
These major arteries include the carotid artery, which takes blood to the brain; the brachial arteries, which take blood to the arms; and the thoracic artery, which takes blood to the thorax and then into the hepatic, renal, and gastric arteries for the liver, kidneys, and stomach, respectively. The iliac artery takes blood to the lower limbs. The major arteries diverge into minor arteries, and then into smaller vessels called arterioles, to reach more deeply into the muscles and organs of the body.
Veins and arteries both have two further tunics that surround the endothelium: the middle, tunica media is composed of smooth muscle, while the outer tunica externa is connective tissue collagen and elastic fibers. The elastic, connective tissue stretches and supports the blood vessels, while the smooth muscle layer helps regulate blood flow by altering vascular resistance through vasoconstriction and vasodilation.
The arteries have thicker smooth muscle and connective tissue than the veins to accommodate the higher pressure and speed of freshly-pumped blood. The veins are thinner walled as the pressure and rate of flow are much lower. In addition, veins are structurally different from arteries in that veins have valves to prevent the backflow of blood. Because veins have to work against gravity to get blood back to the heart, contraction of skeletal muscle assists with the flow of blood back to the heart.
According to Gordon, Z. In the fetus, it extends into the umbilical cord. The umbilical arteries supply deoxygenated blood from the fetus to the placenta. Waste products and carbon dioxide from the fetus are sent back through the umbilical cord and placenta to the mother's circulation to be removed.
Click to Enlarge. The fetal circulatory system uses 3 shunts. These are small passages that direct blood that needs to be oxygenated. The purpose of these shunts is to bypass the lungs and liver. That's because these organs will not work fully until after birth. The shunt that bypasses the lungs is called the foramen ovale. This shunt moves blood from the right atrium of the heart to the left atrium. The ductus arteriosus moves blood from the pulmonary artery to the aorta.
Oxygen and nutrients from the mother's blood are sent across the placenta to the fetus. The enriched blood flows through the umbilical cord to the liver and splits into 3 branches. The blood then reaches the inferior vena cava. This is a major vein connected to the heart.
Most of this blood is sent through the ductus venosus. This is also a shunt that lets highly oxygenated blood bypass the liver to the inferior vena cava and then to the right atrium of the heart. But most of this highly oxygenated blood flows to a large vessel called the inferior vena cava and then into the right atrium of the heart. When oxygenated blood from the mother enters the right side of the heart, it flows into the upper chamber the right atrium.
Most of the blood flows across to the left atrium through a shunt called the foramen ovale. From the left atrium, blood moves down into the lower chamber of the heart the left ventricle. It's then pumped into the first part of the large artery coming from the heart the ascending aorta. From the aorta, the oxygen-rich blood is sent to the brain and to the heart muscle itself. Blood is also sent to the lower body. Blood returning to the heart from the fetal body contains carbon dioxide and waste products as it enters the right atrium.
It flows down into the right ventricle, where it normally would be sent to the lungs to be oxygenated.
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