26 Female Pelvic Viscera
The female pelvic viscera, as the name suggests, consists of the internal organs located within the pelvic cavity, including the reproductive, urinary and digestive components.
Uterus:
The uterus is a hollow, muscular organ located in the midline of the pelvic cavity situated between the urinary bladder and rectum. It has 4 unique structural regions as depicted below:
- Fundus: the dome shaped, upper portion of the uterus located above the uterine (fallopian) tubes
- Body: the main central portion of the uterus where implantation of the fertilized egg occurs
- Cervix: the lower cylindrical portion of the uterus which projects into the vagina. The cervix has an internal os (opening to the vagina) and the external os (opening to the cervix)
- Vagina: the portion which extends from the vaginal orifice and up to the cervix. It plays key roles in allowing menstrual flow to exit and accommodating the penis during intercourse
figure x. Anterior View; Uterus
Uterine wall:
The uterine wall plays key roles in implantation the fertilized egg, yet it also encompasses several layers:
- Endometrium: the inner lining of the uterus which thickens during the menstrual cycle in preparation for pregnancy. If implantation does not occur, this layer is shed during menstruation
- Myometrium: the thick muscular middle layer responsible for powerful contraction during labor and delivery
- Perimetrium: the outermost layer which is part of the peritoneum which covers the uterus
figure x. Anterior View; Uterus tissue layers
Uterine tubes:
Commonly referred to as the fallopian tubes, the uterine tubes are paired, slender tubes which transport the ovum from the ovaries to the uterus. They are also a common site of fertilization where sperm meets egg.
Each tube contains an infundibulum which is a funnel shaped distal portion with finger like projections (fimbriae) which help capture the release egg during ovulation.
Ovaries:
The ovaries were briefly discussed in Chapter 2 regarding their role as an endocrine gland yet their role is paramount in the female reproductive system. The ovaries are situated lateral to the uterus and inferior to the uterine tubes. They are carefully attached to the uterus via the ovarian ligament and suspended in the pelvic cavity by the suspensory ligament. The ovaries produce and release a mature egg (ovum) during the menstrual cycle (ovulation) about once a month – yet this can vary greatly!
figure x. Anterior View; Uterus, ovaries and infundibulum
Check out this meme about the uterus!
Hint: This meme is referencing the fact that many of us are aware of the uterus as part of the menstrual cycle, but that is not the only role! The diversity of its functions is showcased in this meme.