Anatomy-Lexicon

umbilical cord

definition

The umbilical cord is the connection between the maternal placenta (placenta) and the embryo or fetus. It forms a bridge between the two bloodstreams and therefore serves both to supply the fetus with oxygen and nutrients and to remove metabolic end products such as carbon dioxide. In humans, the umbilical cord, which is around 50 cm long, is usually clamped twice at birth and then cut between the clamps.

anatomy

The umbilical cord is average in humans about 50 cm long, has a About 1.5 to 2 cm in diameter and is spiraled. It arises from the Fusion of yolk duct and sticky stalk. The yolk duct is the connection between the embryonic intestine and the yolk sac. The yolk sac is a fluid-filled bulge that loses size in the course of pregnancy and ultimately disappears almost completely. The sticky stem is the original connection between the embryo and the uterine lining and contains the vascular structures for the later umbilical vessels. At this point on the uterine lining, the placenta develops, which is responsible for supplying the fetus until birth.
The umbilical cord usually emerges centrally from the placenta, but it can also be connected to it at the side. The umbilical cord consists of a "gelatinous connective tissue", which is also called "Wharton jelly"Or"Wharton's jelly" referred to as. It contains many collagens and water-binding substances. This will make that Fabric elastic and resembles the consistency of rubber. The resulting stability and flexibility is important to ensure both the freedom of movement of the fetus and to withstand its "exertions". The tissue is surrounded by the inner membrane of the fetus, which is also called the "amnion" and is responsible for the generation of the Amniotic fluid (Amniotic fluid) is responsible.

The umbilical cord is subject to a constant process of development. In addition to the length and size, it is above all the content that changes. In the mature umbilical cord, embedded in the connective tissue, are the blood vessels that connect the mother's circulation with that of the fetus. Due to its rubber-like substance, the connective tissue prevents the umbilical cord and thus the vessels it contains from kinking, thereby protecting them. At the time of birth there are usually three vessels in the umbilical cord, the so-called umbilical vein (Umbilical vein) and the two umbilical arteries (Umbilical arteries)

Function of the umbilical cord

The umbilical cord serves the Supply of the embryo or fetus with oxygen and nutrients. This is made possible by the umbilical vessels embedded in the tissue. These vessels are an exception. Arteries normally carry oxygen-rich blood and veins carry oxygen-poor blood. In the case of the umbilical cord, however, this is exactly the opposite. The two umbilical arteries transport the depleted, oxygen-poor blood of the fetus to the placenta, where it is washed around by maternal, oxygen- and nutrient-rich blood. The replenished and regenerated blood is then transported via the somewhat larger umbilical vein from the placenta to the fetus in order to supply it.

After the birth, the umbilical cord is tied twice to interrupt the blood circulation. Then the umbilical cord is cut. This usually happens about 5-10 minutes after the birth. From this point on, the infant is responsible for its own care.

Umbilical cord stem cells

Stem cells are immature and undifferentiated body cells. Stem cells are subject to a constant process of division. The daughter cell that is created in the process can either be an undifferentiated stem cell that divides again or has already taken a certain "development direction". This happens through certain messenger substances (Hormones), which activate the cell and “show” to you what type of cell it should transform into. The special thing about it is that Stem cells can transform into several different tissues and thus can fulfill many different functions at the same time. Stem cells are so popular in research because they are so adaptable and because of that have a high potential to heal damage or illnesses caused.
The umbilical cord blood mainly contains "hematopoietic“Stem cells, which ones too Blood stem cells and can differentiate into a wide variety of blood cells. However, the umbilical cord tissue mainly contains "mesenchymal“Stem cells, which after differentiation are like different tissues for example bone, cartilage, muscle or connective tissue can generate.

Cord blood

Cord blood is amazing rich in baby's blood stem cells, since these are on their journey to the Bone marrow are where they ultimately remain and are also to be found in adults. However, it is much easier and more convenient for the patient to draw blood than to have a bone marrow puncture. In addition, the baby's blood stem cells are still very young and therefore very capable of dividing. They have not yet gone through the aging process and are usually virus free. The umbilical cord puncture at birth is painless for mother and child and is very easy to perform. It comes to one little blood loss from about 60-200 milliliters, which but very well compensated by healthy children becomes. All these reasons have led many medical professionals to increasingly research with umbilical cord blood.
It is now mainly used for blood diseases such as leukemia, as well as some other hereditary diseases. Here one can Stem cell transplant lead to healing. Also for the therapy of Type 1 diabetes and autism is currently being researched.

Store umbilical cord blood

Umbilical cord blood (and thus the stem cells it contains) can be removed from the umbilical cord through a puncture at birth and then stored. As described above, blood stem cells have numerous areas of application (blood cancer, hereditary diseases) and are therefore of great medical importance. The blood taken is usually stored and stored at around -196 ° C with liquid nitrogen. The costs for private storage are between 1500 and 3000 euros and must be taken over by the parents. However, there is also the possibility of the blood to leave free of charge to a public donor bank for stem cell donation.

Umbilical cord puncture

With umbilical cord puncture, also "Chordocentesis“Called, it is a voluntary, painless but invasive method of prenatal diagnosis, so the special prenatal care. A long and thin needle is used to puncture the baby's umbilical vein through the mother's abdominal wall. Through a parallel Ultrasonic the position of the puncture needle is constantly checked. The blood drawn (around one to two milliliters) is then examined in the laboratory. The diagnostic spectrum extends over the determination of the Blood count, so the Number and shape of each blood cell, as well as various antibodythat can indicate various diseases, the Detection of infections and metabolic disorders up to Chromosome determination.

An umbilical cord puncture is no routine examination and must therefore be desired by the parents. In most cases only the blood values are determined. That means, for example blood type with the rhesus factor, the Hematocrit and the blood cells that Hemoglobin content, as Antibodies to certain infections (Rubella, herpes, toxoplasmosis). A chromosome examination in which various hereditary diseases can be determined is rather rare.
Invasive examination methods always involve risks. In the case of umbilical cord puncture, it can occur in rare to exceptional cases, among other things Amniotic fluid loss, infections, needle injuries to the mother and fetus, bleeding and miscarriage. The necessity of such an examination should therefore be well discussed and weighed up in advance in a consultation between the doctor and the pregnant woman / parents.

The umbilical cord incident

A distinction is made between a "Presence of the umbilical cord"And a"Umbilical cord prolapse“.

A Presence of the umbilical cord describes the situation that, with the amniotic sac still intact, the umbilical cord is placed in front of the baby's previous part of the body. The umbilical cord can be repositioned prenatally by positioning the pregnant woman and therefore does not exclude vaginal birth, but it should be constantly monitored.
A Umbilical cord prolapse on the other hand, denotes a medical emergency in which the umbilical cord reaches the previous part of the baby due to a premature rupture of the bladder or during the birth. This can lead to the umbilical cord becoming trapped. However, since this is responsible for supplying the baby with oxygen, immediate action must be taken to prevent permanent damage to the child.The pregnant woman's pelvis is raised to reduce the pressure on the umbilical cord. A vaginal birth is then usually impossible and the child is born by caesarean section.

When does the umbilical cord fall off?

After the umbilical cord has been severed, a remnant approximately 2-3 cm long remains. This dries up over time because it is no longer supplied with blood. As a result, the umbilical remnant turns brown to brown-black and falls off by itself after about five to fifteen days. For most babies, however, this is achieved after ten days at the latest. What remains is a small open wound, which heals within a few days. These however, care should be taken to protect the wound from infection and accelerate the healing process.