Uterus: Miscellaneous | Medical Science Optional Notes for UPSC PDF Download

Uterus-Gross Anatomy

Gross Anatomy and Relationships:

1. The uterus, an organ vital for childbearing in females, is positioned in the pelvis between the bladder and rectum.
2. Anteversion and Anteflexion: Typically, the long axis of the uterus forms an approximately 90-degree angle with the long axis of the vagina, opening forward. The forward bending of the uterus in relation to the vagina is known as anteversion. Additionally, the uterus exhibits a slight flexion on itself, referred to as anteflexion, with an angle of anteflexion measuring 125 degrees.
3. The body comprises: 
   a. A fundus,
   b. Two surfaces – anterior or vesical and posterior or intestinal, and
   c. Two lateral borders.
4. The fundus is constituted by the free upper end of the uterus, situated above the openings of the uterine tubes. It assumes a convex, dome-like shape, and the fertilized oocyte typically implants in the posterior wall of the fundus.
5. The anterior or vesical surface is flat and in proximity to the urinary bladder.
   
6. The convex posterior or intestinal surface is associated with the coils of the terminal ileum and the sigmoid colon. Covered with peritoneum, it constitutes the anterior wall of the rectouterine pouch.
7. Each rounded and convex lateral border serves as an attachment point for the broad ligament of the uterus, linking it to the lateral pelvic wall. The uterine tube opens into the uterus at the upper end of this border.
8. The cervix, the lower cylindrical section of the uterus, exhibits less mobility than the body. Measuring approximately 2.5 cm in length, it is slightly wider in the middle than at either end. The lower part of the cervix extends into the anterior wall of the vagina.

Supports of the Uterus

The uterus, a dynamic organ, undergoes significant alterations in size and shape throughout the reproductive phase of life. It is sustained and protected from descent by the following supports:

Uterus-blood supply

The uterine artery provides the blood supply to the uterus, and the venous drainage occurs through a plexus in the broad ligament, ultimately draining into the uterine veins.

Arteries

The uterine artery originates as a branch of the anterior division of the internal iliac artery. A significant branch ascends the uterus in a tortuous path within the ligament until it reaches the region of the ovarian hilum, where it forms an anastomosis with branches of the ovarian artery. Another branch descends to supply the cervix and forms anastomoses with branches of the vaginal artery.

Each uterine artery emits numerous branches that penetrate the uterine wall, dividing and running circumferentially as groups of anterior and posterior arcuate arteries. The terminal branches within the uterine muscle are characterized by their tortuosity and are referred to as helical arterioles.

Veins

The uterine veins course laterally within the broad ligaments, closely following the path of the arteries and traversing over the ureters. These veins ultimately drain into the internal iliac veins. The uterine venous plexus forms connections with the venous plexuses of the vagina and ovaries through anastomoses.

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Uterus-Lymphatic drainage

• Lymphatic vessels within the uterus are present in both the superficial (subperitoneal) and deep layers of the uterine wall. Collecting vessels from the body of the uterus and cervix travel laterally in the parametrium, reaching three main groups of lymph nodes: the external and internal iliac nodes, as well as the obturator nodes.
• Lymph vessels originating from the fundus of the uterus and the uterine tubes may accompany the lymph drainage from the ovaries to the para-aortic nodes.
• The area surrounding the isthmus of the uterine tube might drain along the round ligament to the superficial inguinal nodes.

Uterus-Clinical Anatomy

• Retroverted Uterus: In certain instances, the uterus aligns in a straight line with the vagina, a condition known as a retroverted uterus.
• Prolapse of the Uterus: Occasionally, the uterus descends into the vagina, causing prolapse. This condition results from the weakening of various supports for the uterus.
• IUCD (Intrauterine Contraceptive Device): The insertion of a foreign body into the uterus can prevent the implantation of a fertilized oocyte. This principle forms the basis for various intrauterine contraceptive devices used to prevent pregnancy.
• Hysterectomy: The removal of the uterus is termed a hysterectomy. The opening of the uterus is referred to as hysterotomy, while the stabilization of an abnormally mobile uterus is termed hysteropexy.
• Hysterosalpingography: Radiological visualization of the uterus and uterine tubes is possible by filling them with a radiopaque dye, a procedure known as hysterosalpingography.
• D and C (Dilation and Curettage): A therapeutic procedure involving the dilation of the cervix and curettage of the endometrium is performed to address dysfunctional uterine bleeding.

Uterus - Repeats

• Discuss relations and supports of uterus. Add a note on its applied anatomy. (2011) 
• Write gross anatomy of uterus. Add notes on supports of uterus, its histological structure and development (2005).