Navel -its importance and significance
The navel also called the belly button or umbilicus is a structure that does not receive much attention in adult life because of its obvious significance in the fetus. It is a scar left on the abdomen which shows the point of connection between the mother and the baby via the placenta in intrauterine life (life inside the womb).
Upon delivery, the umbilical cord is clamped and cut, leaving a little portion on the skin. This portion is cleaned continually and within a little period of time, falls off completely leaving a scar behind which is referred to as the navel.
This structure has some significance in fetal as well as in adult life; some of which are highlighted below:
Nutrient for the fetus
The umbilicus is what connects the umbilical cord to the mother, serving as a means by which the fetus sends out waste products and receives nutrients for its growth and development.
Because it is a scar that everyone has, the umbilicus is commonly used as a landmark in the body. It lies between the third and fourth lumbar vertebra (L3 and L4) in most people, though there may be little variations.
It is seen as a watershed as regards drainage of the lymph, and venous blood. This means that above the umbilicus, venous blood and lymph will flow upwards, and below it, venous blood and lymph will flow downwards.
Furthermore, to carry out an appendectomy (surgical removal of the appendix), surgeons use the umbilicus as a reference point. The incision is made at McBurney’s point, which lies at a point 2/3rd from the umbilicus to the anterior superior iliac spine (ASIS).
The umbilicus is also a meeting point of three major systems in fetal life – the excretory, digestive, and the vascular/circulatory system. These systems have various representations in the fetus.
Furthermore, minimally invasive surgeries like laparoscopy are performed through the umbilicus for cosmetic purposes. Many more surgeries in the future will be performed through this way to minimize scarring on the skin.
Any pain from damage or injury to an organ inside the body is felt most times at a different point from the origin of the pain. This type of pain is said to be referred. Referred pain is usually referred to a site of similar developmental origin or nerve supply.
For instance, when the intestinal walls are scarred, the pain is usually felt at a different spot called the epigastric region. Likewise, the umbilicus is the major site of referred pain in appendicitis (inflammation of the appendix). This is used by physicians as a major source of diagnosis.
Ailments and Diseases that can affect the umbilicus
The umbilicus is one of the sites where portocaval anastomosis occurs (portal veins anastomose with systemic veins). When there is portal hypertension (increase in blood pressure in portal veins), the veins become enlarged and become prominent on the surface around the umbilicus due to the increased pressure.
This is called caput-medusae, and it presents as radiations seen around the navel.
Dirt and bacteria can accumulate at the umbilicus causing infections like omphalitis which happens majorly in newborn.
As earlier stated, some weeks after delivery the umbilicus heals and leaves a scar. If this healing occurs as it should, it leaves no complications.
However, if there is a weakness at the umbilicus, it leads to umbilical hernia which may show sometimes as a bulge at the umbilicus.
Recall that in fetal life, the umbilicus is a meeting point of three important systems:
- the excretory system represented by the urachus
- the digestive system represented by the vitellointestinal duct and
- the vascular system represented by the umbilical veins and arteries (collectively called the umbilical vessels).
If the urachus persists, it forms a urinary fistula which opens at the umbilicus. The same is the case when the vitellointestinal duct remains; it forms a faecal fistula at the umbilicus.
A fistula is an abnormal connection between vessels or organs, which should have no connections normally. The fecal fistula causes fecal waste (feaces) in the gut to come out through the umbilicus, while the urinary fistula causes urine to flow out from the bladder to the umbilicus. These fistulas can be removed surgically.