Female accessory ducts

The Fallopian tube, also known as the oviduct or uterine tube, is a pair of muscular ducts that transport the ovum from the ovary to the uterus. It plays a crucial role in fertilization by providing the site where sperm meets the egg.

Each Fallopian tube is about 10-12 cm long and extends from the ovary to the uterus. It is lined internally by ciliated epithelium that helps in the movement of the ovum. It is divided into four regions:

Infundibulum: It is the funnel-shaped proximal (first) part near the ovary. It has finger-like projections called fimbriae, which help capture the ovum released from the ovary during ovulation. The ostium is the opening at the end of the infundibulum through which the egg enters the Fallopian tube.

Ampulla: It is the widest and longest part of the Fallopian tube. This is the site where fertilization occurs when a sperm meets the ovum. It has a thin wall and is highly coiled to facilitate the movement of the egg.

Isthmus: It is a short, narrow, and thick-walled segment that follows the ampulla. It connects the ampulla to the uterus and helps push the fertilized egg toward the uterine cavity.

Uterine part (Interstitial part): It is the shortest and narrowest part of the Fallopian tube. This region passes through the uterine wall and opens into the uterine cavity.

Collection of the Ovum – Fimbriae guide the released ovum into the Fallopian tube.

Site of Fertilization – The ampulla is where sperm meets the ovum to form a zygote.

Transport of Zygote – Cilia and muscle contractions help move the zygote towards the uterus.

Provides a Suitable Environment – Secretions from the Fallopian tube nourish both the ovum and sperm.

The uterus, also called the womb, is a hollow, muscular, pear-shaped organ located in the pelvic cavity, between the urinary bladder and the rectum. It plays a vital role in menstruation, implantation, pregnancy, and childbirth.

The uterus is divided into three main regions:

Fundus: The upper, dome-shaped part of the uterus. It is the widest part and receives the fallopian tubes from both sides. Normally, implantation of the embryo occurs here.

Body (Corpus): The middle and largest part of the uterus. It is highly muscular and flexible, allowing it to expand during pregnancy. It tapers downward toward the cervix.

Cervix: The lower narrow part of the uterus. It connects the uterus to the vagina through the cervical canal. The cervix has two openings: Internal Os – Opening between the cervix and body of the uterus. External Os – Opening between the cervix and the vagina.

The uterus has three histological layers:

Perimetrium (Outer Layer): It is the thin outer covering made of peritoneum (a type of connective tissue). Protects the uterus and holds it in place.

Myometrium (Middle Layer): The thickest and muscular layer. Made of smooth muscle fibers, responsible for: Strong contractions during childbirth (Labour or Parturition). Menstrual cramps during menstruation.

Endometrium (Inner Layer): Highly vascularized mucous membrane. Lined with simple columnar epithelium. It undergoes cyclic changes during the menstrual cycle: It thickens to prepare for implantation. If fertilization does not occur, it sheds during menstruation.

Menstruation – The endometrial lining is shed if fertilization does not occur.

Implantation – The uterus provides a site for the fertilized egg (zygote) to attach and grow.

Fetal Development – The uterine wall expands to accommodate the growing fetus.

Nourishment and Protection – The placenta forms in the uterus and provides nutrients and oxygen to the fetus.

Childbirth (Parturition) – The myometrium contracts forcefully to push the baby out during delivery.

The vagina is the female copulatory organ, a muscular, elastic, and tubular structure that plays a vital role in reproduction. It serves as the passageway for sperm during copulation (sexual intercourse), facilitates menstrual flow, and functions as the birth canal during parturition (childbirth).

Structure and Characteristics

Length and Location: The vagina is 7 to 10 cm long in an adult female. It extends from the cervix of the uterus to the vaginal orifice (opening), which is in the vestibule of the vulva.

Vaginal Orifice: The external opening of the vagina is called the vaginal orifice.

In young girls, it is partially covered by a thin membrane called the hymen.

Hymen: The hymen is a thin mucous membrane that partially covers the vaginal opening.

It may be torn due to sexual intercourse, physical activities (cycling, horse riding), or accidental injury.

In some females, the hymen may remain intact even after intercourse, making it an unreliable indicator of virginity.

Copulatory Function: The vagina receives the penis and sperm during intercourse, allowing fertilization to occur.

Passage for Menstrual Flow: The vagina serves as an outlet for menstrual blood during the menstrual cycle.

Birth Canal: The vagina acts as the birth canal during parturition (childbirth). The strong muscular contractions help in the expulsion of the baby. Protection Against Infections: The acidic pH of the vagina (due to lactic acid production) prevents the growth of harmful bacteria and infections.