In human
anatomy
Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...
, the median umbilical ligament is an unpaired midline ligamentous structure upon the lower inner surface of the anterior abdominal wall.
It is covered by the median umbilical fold.
The median umbilical ligament represents the remnant of the
fetal
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 stage, the fetal stage of development takes place. Prenatal development is a ...
urachus.
It extends from the apex of the
bladder
The bladder () is a hollow organ in humans and other vertebrates that stores urine from the kidneys. In placental mammals, urine enters the bladder via the ureters and exits via the urethra during urination. In humans, the bladder is a distens ...
to the
umbilicus, on the deep surface of the anterior abdominal wall.
The median umbilical ligament represents one of the five ligaments of the internal anterior abdominal wall inferior to the umbilicus; laterally on either side of it are one
medial umbilical ligament and finally one
lateral umbilical ligament.
Development
The median umbilical ligament begins as the
allantois in the
embryonic period. It then becomes the
urachus 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 ...
.
This later develops into the median umbilical ligament at birth.
It is also formed from the
cloaca
A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilagin ...
in utero.
Function
The median umbilical ligament has no known function.
Clinical significance
The median umbilical ligament may be used as a landmark for surgeons who are performing
laparoscopy, such as laparoscopic
inguinal hernia
An inguinal hernia or groin hernia is a hernia (protrusion) of abdominal cavity contents through the inguinal canal. Symptoms, which may include pain or discomfort especially with or following coughing, exercise, or bowel movements, are absen ...
repair. Other than this, it has no function in a born human and may be cut or removed with impunity.
It contains the
urachus, which is the obliterated form of the
allantois. The allantois forms a communication between the
cloaca
A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilagin ...
(terminal part of
hindgut
The hindgut (or epigaster) is the posterior ( caudal) part of the alimentary canal. In mammals, it includes the distal one third of the transverse colon and the splenic flexure, the descending colon, sigmoid colon and up to the ano-rectal junct ...
) and the
amniotic sac
The amniotic sac, also called the bag of waters or the membranes, is the sac in which the embryo and later fetus develops in amniotes. It is a thin but tough transparent pair of biological membrane, membranes that hold a developing embryo (and l ...
during
embryonic development
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm, sperm cell (spermat ...
. If the
urachus fails to close during fetal life, it can result in anatomical abnormalities such as a
urachal cyst,
urachal fistula,
urachal diverticulum or
urachal sinus.
In very rare cases the
urachus can fail to close fully. This can lead to a condition known as a ''
patent urachus'' (also ''urachal fistula''). Although it is mainly immediately diagnosed after birth it can occur at any stages of life. In this condition there is a functional tubular connection between the umbilicus and the bladder which can lead to urine draining through the umbilicus. Patients often present with umbilical wetness or recurring infections in the area. Treatment options include laparoscopic surgery, excision of the umbilicus or conservative therapy. Due to limited risks conservative therapy, while still being chosen rarely, has been gaining some traction in the last years.
Society and culture
The median umbilical ligament was jokingly referred to as "Xander's ligament" in a
YouTube
YouTube is an American social media and online video sharing platform owned by Google. YouTube was founded on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim who were three former employees of PayPal. Headquartered in ...
video published by Dr. Alexander R. Toftness (aka. ARTexplains on YouTube), and this name was subsequently used on
Wikipedia
Wikipedia is a free content, free Online content, online encyclopedia that is written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and La ...
for a short time.
This term was later used in a paper published in
Mayo Clinic Proceedings.
The term has also appeared in a medical textbook of
obstetrics
Obstetrics is the field of study concentrated on pregnancy, childbirth and the postpartum period. As a medical specialty, obstetrics is combined with gynecology under the discipline known as obstetrics and gynecology (OB/GYN), which is a su ...
and
gynaecology
Gynaecology or gynecology (see American and British English spelling differences) is the area of medicine concerned with conditions affecting the female reproductive system. It is often paired with the field of obstetrics, which focuses on pre ...
.
References
External links
* Median umbilical ligament
** - "The inguinal canal and derivation of the layers of the spermatic cord."
** - "The Male Pelvis: The Urinary Bladder"
**
* Median umbilical fold
** - "Internal surface of the anterior abdominal wall."
{{Authority control
Abdomen
Ligaments