What is the Function and Structure of Fallopian Tubes?

Fallopian tube Meaning

Fallopian tube is a pair of thin tubes that lead from the ovaries of the female mammals to the uterus through the uterotubal junction.

Fallopian tubes have a vital role to play in the transportation of gametes, in the process of fertilization and in the early development of the embryo that could be influenced by a range of aspects impairing fertility.

Uterine tube or fallopian tube is a hollow muscular structure that connects the ovaries to the uterus. Here, let’s learn the structure and function of the uterine tube in detail.

Table of Content:

• What is Fallopian tube?
• Fallopian tube Anatomy
• Fallopian tube Diagram
• Fallopian tube Location
• Fallopian tube Structure
• Fallopian tube Functions
• Uterus and Fallopian tubes
• Frequenty Asked Questions

The fallopian tube is a part of the female reproductive system in mammals. It is the female accessory duct and is also known as oviduct. A pair of fallopian tubes connect the ovaries to the uterus. The main function of the fallopian tube is to collect the mature ovum from ovaries and provide passage to the fertilized ovum to reach the uterus for implantation. The fertilisation of the ovum with sperm takes place in the ampulla region of the fallopian tube.

Fallopian tube – Origin

In the 4th or 6th week, the Mullerian ducts or paramesonephric ducts take form in the female embryos because there is no anti-mullerian hormone (AMH). The cranial terminals of these ducts gradually start forming the fallopian tubes due to the stimulation of estrogen. The paramesonephric ducts caudally unite in the midline and eventually forms the uterus and the superior vagina.

These fallopian tubes are hollow seromuscular structures originating at the uterine horns laterally extending in the superior edge of the mesosalpinx of the broad ligament and end near the ipsilateral ovary.

The fallopian tube shows 4 different anatomical structures – uterine, ampulla, isthmus and the infundibulum.

The uterine section medially is the uterine ostium and a short part near the uterine horn. The isthmus is seen adjacent to the uterine section. Ampulla is the common site of fertilization, it is lateral to the isthmus.

Distal from the uterus, the infundibulum terminates at an abdominal ostium opening into the peritoneal cavity and the fimbriae. It traps the released oocyte at the time of menstrual cycle. The fimbria ovarica (fimbria) forms a connection between the infundibulum and the ovary closeby. Furthermore, it provides a region for fertilization to take place. The fallopian tube serves as a passageway for the gamete to the ovary and the uterus.

Different parts of Fallopian tube

Infundibulum – Nearest part to the ovaries, the Infundibulum is the funnel-like part of the tube and shows the ginger-like projections called fimbriae which extend towards the ovary. Fimbriae traps eggs once they are released from the ovary and take in the fallopian tube.

Ampulla – Main passageway in the uterine tube and is seen between the isthmus and infundibulum. It is the site of fertilization.

Isthmus – Small passageway connecting the ampulla to the part of the fallopian tube which is nearest to the uterus – the intramural part.

Interstitial part – This part reaches the top of the uterus and leads into the uterine cavity. Here an embryo can embed into the uterine wall and eventually develop into the fetus.

There are two slender, long fallopian tubes – one on the left side of the uterus and one on the right side. Each tube stretches from the ovary leading into the uterus. Female gametes move from the ovaries all through the fallopian tubes leading into the uterus. On each side of the uterus, there is one ovary and one fallopian tube in the female reproductive system.

A pair of fallopian tubes or uterine tubes are part of the mammalian female reproductive system. The main characteristics of fallopian tubes are:

• It is ~ 10 to 12 cm long.
• Fallopian tubes connect both the ovaries to the uterus.
• The fallopian tube is composed of three parts, infundibulum, ampulla and isthmus.
• Oviduct is lined by ciliated epithelium, which helps in the movement of secondary oocytes towards the uterus.
• Infundibulum – It is a funnel-shaped structure present close to the ovaries. This part collects the ovum after ovulation. The finger-like projections called fimbriae at the edges near the ovaries help in ovum collection.
• Ampulla – Infundibulum leads into a wider ampullary region. Here fertilisation takes place.
• Isthmus – It is the last part of the fallopian tubes. It has a narrow lumen and connects to the uterus.

The main function of the uterine tubes is to transport secondary oocytes after ovulation. Fertilisation takes place in the fallopian or uterine tubes. If the ovum is not fertilised then it gets degenerated here. After fertilisation, the zygote moves towards the uterus with the help of ciliated epithelium and muscle movement of the fallopian tube.

Initial embryo development occurs in the fallopian tube. The embryo enters the uterine cavity on the fifth day and gets implanted on the sixth day after fertilisation.

The uterus is a hollow, muscular structure, shaped as an upside-down pear showing a thick lining with muscular walls. It can be found near the floor of the pelvic cavity allowing a fertilized egg to get embedded and grow.  It enables the inner lining of the uterus to accumulate till the implantation of the fertilized egg or until it gets sheds at the time of menstrual cycle.

Muscles of the Uterus

The muscles of the uterus are said to be one of the strongest and are able to contract and expand to accommodate a growing foetus and to push at the time of labour. The rhythmic contraction of the muscles at the time of an orgasm is suggested to aid in pushing or guiding the sperm all the way to the uterus and fallopian tubes, where fertilization is possible.

Structure of Uterus

The uterus is approximately 3 inches in length with a width of about 2 inches. However, at the time of pregnancy there is a dramatic change. The fundus is the top rim of the uterus. The body of the uterus and fundus of the uterus is referred to by the uterine cavity.

Uterus are supported by ligaments which attach from the body of the uterus to the abdominal and pelvic wall. At the time of pregnancy, the ligaments tend to prolapse as a result of the growing uterus and retracts post parturition.

Once the egg reaches the fallopian tube, the fine hair in the lining of the tube helps push it towards the uterus. The developing egg cell reaches the length of the fallopian tube in about 4-5 days. Fertilization takes place if enough sperm is ejaculated during coitus and there is oocyte in the fallopian tube.

The fertilized egg, after fertilization, continues to the uterus and embeds itself in the wall of the uterus where it develops and grows.

Clinical Significance

• Ectopic pregnancy – It is the condition when the embryo gets implanted in the fallopian tube itself instead of the uterus. It is also known as tubal pregnancy. Any damage in the fallopian tube lining may hinder the further movement of fertilised egg and it gets lodged there. It can lead to internal bleeding and rupture.
• Surgery – The surgical removal of fallopian tube is termed a salpingectomy. The removal of atleast one ovary along with fallopian tube is called a salpingo-oophorectomy. Also, the surgery done to remove the tube obstruction is called tuboplasty.

This was in brief about Fallopian tubes. Test your understanding with MCQs on Female Reproductive System, only at BYJU’S.

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