The Female Reproductive System: Structure and Function

Female reproductive system Primary sex organs ● Ovary which produces the egg ● Paired structure ● Produces female sex hormone Internal and external organs ● Uterine tubes (fallopian tubes) ● Uterus (hollow muscular structure where implantation occurs and the foetus develops) ● Vagina (posterior to the bladder) Ovary ● Paired female gonad ● Inside the pelvic cavity ● Lateral to the uterus, very close to the pelvic walls ● For egg and estrogen production (female sex hormone) ○ Egg production occurs in the developing foetus ○ Produces from 5-7 million eggs but only 2 million survive at birth ○ Most eggs degenerate and they end up with 400 000 ● The uterine tubes being right next to the ovaries increases the likelihood of the tubes being able to scoop out the egg and scoop it into the uterine tubes ● Ligaments ○ Ovarian ligament (ovary to uterus) ■ Lateral to uterus ■ Posterior to uterine tube ○ Suspensory ligament to ovary (ovary to pelvic wall) ■ Starts at the pole where uterine tubes are located and extends towards the pelvic cavity ■ Pathway that the blood vessels have pierced through the peritoneum above ■ Ovarian artery and ovarian vein have pushed through the peritoneum and brought the peritoneum with it and attached to the ovary ■ Holds the ovary in place from above ■ Holds the blood vessels which supply and drain the ovary Uterine tubes ● Paired ● Extends between the ovary and uterus ● Functions: ○ Receives the egg released from the ovary into the tube ○ Transports the egg to the uterus ● Typical site of fertilisation ● Regions ○ Fimbriae ■ Finger like projections ■ Can be seen from a macroscopic perspective ■ Beat when the egg is released to create turbulence so that the egg can be drawn and swept into the opening of the uterine tube ○ Infundibulum ■ Circular opening of the uterine tube ■ Behind the fimbriae ■ Trumpet shape ○ Ampulla ■ Fertilisation typically occurs here ■ Widening of the tube ○ Isthmus ■ Narrowing of the uterine tube The uterus ● Single, hollow muscular structure ● Posterior and superior to urinary bladder ● Anterior to the rectum ● Regions ○ Fundus (rounded superior structure) ○ Body (large muscular part) ○ Cervix (neck of the uterus, narrowing of the cervix to the vagina which is inferior to the cervix) ● Layers ○ Perimetrium (outer, inferior part of the peritoneum lies on top of the perimetrium) ○ Myometrium (middle, muscle) ○ Endometrium (inner, where implantation occurs, has resources to provide safe space for the foetus to develop, if no implantation it will shed and create a new space for further implantation) ● Ligaments ○ Broad ligament ■ Where the peritoneum reflects over the surface of the uterus ■ Reflects over the uterine tube ■ Spreads broadly over the uterus and the uterine tubes ■ Purpose is to maintain the position of the uterus and uterine tubes especially during pregnancy ○ Round ligament ■ Extends from the body of the uterus ■ Extends laterally close to the pelvic cavity ■ Similar path to the ductus deferens ■ Pierces through the inguinal canal (anterior abdominal wall) ■ Extends anteriorly into the mons pubis (fatty mound forms part of external genitalia, anterior to the public bone) ■ Two arms coming to the front of the pelvic cavity, piercing through the anterior abdominal wall and embedding into the mons pubis ■ Purpose is to maintain the position of the uterus and uterine tubes especially during pregnancy Vagina ● Ensheathe the penis to maximise contact with the female reproductive tract ● Organ of copulation ● Posterior to the urethra ● Thin but distensible (can stretch to allow the passage of the baby's head through the birth canal) ● Extends higher than cervix ○ Spaces between the vaginal wall meets the cervix there are extra spaces called fornices (lateral, anterior and posterior), additional stretch space for when the cervix thins out and opens out during labour ● Vaginal orifice open into the external environment through the vestibule External genitalia ● Vestibule (bounded by the inner lips of the external genitalia known as the labia minora small lips) ● Labia minora ● Labia majora = bilateral structure ○ Larger lips to protect the vestibule ● Anterior = external urethral orifice ● Opening to the vagina = more posterior ● Clitoris ○ Filled with erectile tissue and synonymous with the penis ○ Blunt ended structure with no opening ○ Where the labia minora meet ventrally in the area of the vestibule ● Mons pubis ○ Round ligament of the uterus comes through the inguinal canal and embeds itself on the mons pubis (fatty mound at the level of the pubic bones)