The umbilical artery is a paired
artery
An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...
(with one for each half of the body) that is found in the
abdominal and
pelvic regions. In the
fetus
A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...
, it extends into the
umbilical cord
In Placentalia, placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord i ...
.
Structure
Development
The umbilical arteries supply systemic arterial blood from the fetus to the
placenta. Although this blood is sometimes referred to as deoxygenated blood it is not, and has the same oxygen saturation and nutrients as blood distributed to the other fetal tissues. There are usually two umbilical arteries present together with one
umbilical vein in the
umbilical cord
In Placentalia, placental mammals, the umbilical cord (also called the navel string, birth cord or ''funiculus umbilicalis'') is a conduit between the developing embryo or fetus and the placenta. During prenatal development, the umbilical cord i ...
. The umbilical arteries surround the
urinary bladder
The bladder () is a hollow organ in humans and other vertebrates that stores urine from the Kidney (vertebrates), kidneys. In placental mammals, urine enters the bladder via the ureters and exits via the urethra during urination. In humans, the ...
and then carry all the deoxygenated blood out of the fetus through the umbilical cord. Inside the placenta, the umbilical arteries connect with each other at a distance of approximately 5 mm from the cord insertion in what is called the ''Hyrtl anastomosis''. Subsequently, they branch into
chorionic arteries or ''intraplacental fetal arteries''.
The umbilical arteries are actually the anterior division of the
internal iliac arteries, and retain part of this function after birth.
The umbilical arteries are one of two arteries in the human body that carry deoxygenated blood, the other being the
pulmonary arteries
A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the ''main pulmonary artery'' or ''pulmonary trunk'' from the heart, and ...
.
The
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
inside the umbilical artery is approximately 50
mmHg. Resistance to blood flow decreases during development as the artery grows wider.
After development
The umbilical artery regresses after birth. A portion obliterates to become the
medial umbilical ligament (not to be confused with the
median umbilical ligament, a different structure that represents the remnant of the embryonic
urachus). A portion remains open as a branch of the anterior division of the internal iliac artery. The umbilical artery is found in the
pelvis
The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...
, and gives rise to the
superior vesical arteries, which in males usually supplies the
artery to the ductus deferens. Alternately, the latter artery can be supplied by the
inferior vesical artery in some individuals.
Clinical significance
A
catheter
In medicine, a catheter ( ) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. ...
may be inserted into one of the umbilical arteries of critically ill babies for
drawing blood for
testing.
This is a common procedure in
neonatal intensive care, and can often be performed until 2 weeks after birth (when the arteries start to decay too much). The umbilical arteries are typically not suitable for
infusions.
Additional images
File:Gray31.png, Model of human embryo, 1.3 mm. long.
File:Gray1111.png, Transverse section of human embryo, eight and a half to nine weeks old.
File:Gray1115.png, Tail end of human embryo, twenty-five to twenty-nine days old.
File:Inguinal fossae.PNG, Inguinal fossae
File:Slide4khi.JPG, Umbilical artery. Deep dissection. Anterior view.
File:Slide4BLA.JPG, Umbilical artery. Deep dissection. Serial cross-section.
See also
*
Single umbilical artery
References
External links
* - "The Female Pelvis: Branches of Internal Iliac Artery"
{{DEFAULTSORT:Umbilical Artery
Arteries of the abdomen
Embryology of cardiovascular system