Question

An often-seen complication of pregnancy is that of a fertilized ovum implanting itself in tissue other than the uterine wall. There are multiple sites where this may occur, but the most common site for an ectopic pregnancy is A. isthmic. B. cornual. C. ampullary. D. abdominal.

Short answer

C. ampullary.

Step-by-step solution

Understand the Question

The question is asking for the most common site of an ectopic pregnancy, where a fertilized ovum implants outside the uterine wall.

Know the Potential Locations

Identify the options provided: isthmic, cornual, ampullary, and abdominal. These are all potential sites for ectopic pregnancies.

Recall Medical Knowledge

Use knowledge of reproductive biology to determine which location is most common for ectopic pregnancies. The fallopian tubes are the most common site, with the ampullary region being the most commonly affected part.

Select the Correct Option

Among the given choices, the ampullary region is correct since it is the most common site for ectopic pregnancies.

Key concepts

fertilized ovum implantation

When an egg is fertilized by a sperm, it forms a zygote. This zygote then travels down the fallopian tube towards the uterus. Normally, the fertilized ovum implants itself in the lining of the uterus, where it can develop into an embryo.

However, sometimes this process does not go as planned. The fertilized ovum might implant itself outside the uterus. This abnormal implantation leads to an ectopic pregnancy. Ectopic pregnancies most commonly occur in the fallopian tubes but can also happen in other locations.

Implantation outside the uterus is problematic because these other tissues cannot support the growing embryo properly. This can cause serious and potentially life-threatening complications for the mother.

In summary, ‘fertilized ovum implantation’ typically refers to the normal process of a fertilized egg attaching itself to the uterine wall. Any deviation from this normal process can lead to complications such as an ectopic pregnancy.

fallopian tubes

The fallopian tubes are an essential component of the female reproductive system. They connect the ovaries to the uterus. Each month, during ovulation, an ovary releases an egg into the corresponding fallopian tube.

Fertilization usually occurs in the fallopian tube. The fertilized egg then travels down the tube to the uterus.

There are different parts of the fallopian tubes, including:

• Isthmic: closest to the uterus.
• Ampullary: the widest and longest section.
• Infundibulum: closest to the ovary, with finger-like projections called fimbriae.

In the case of an ectopic pregnancy, the fallopian tubes are the most common site. The ampullary region is particularly prone to ectopic pregnancy because it's where fertilization typically occurs. If the fertilized egg gets stuck here, it can’t reach the uterus, leading to complications.

ampullary region

The ampullary region is a specific part of the fallopian tube. It is the widest and longest section, making it a critical location for fertilization.

After ovulation, when an egg is released from the ovary, it enters the ampullary region. Here, it meets sperm and fertilization usually occurs. The fertilized ovum then continues its journey to the uterus.

The ampullary region is a common site for ectopic pregnancies. If the fertilized ovum implants in this region instead of traveling to the uterus, an ectopic pregnancy occurs.

This location is vulnerable because the fertilized egg might have trouble moving from the wide ampullary section to the narrower isthmic section. When the embryo begins to grow, it can stretch and potentially rupture the fallopian tube, which is a medical emergency.

Understanding the structure and function of the ampullary region helps in grasping why this area is particularly susceptible to ectopic pregnancies.