Presentation on theme: "District I ACOG Medical Student Education Module 2011"— Presentation transcript:
1District I ACOG Medical Student Education Module 2011 Pelvic AnatomyDistrict I ACOGMedical Student Education Module 2011
2Gynecologic Viscera Uterus: thick, muscular organ Derived from the fusion of the paramesonephric (mullerian) ducts.These ducts also form the upper 2/3 of the vagina and the fallopian tubes.Divided into 3 segments: fundus, lower segment and cervix.3 layers: serosa, myometrium (smooth muscle), and endometrium.
3Gynecologic VisceraFallopian tubes: cm in length, <1 cm in diameter.Isthmus - 1 mm in diameter - perfect spot for tubal ligation.Ampulla - 6mm in diameter - fertilization occurs here as well as most ectopics.
4Ligamentous Support Round Ligament: Fibrous and muscle tissue Anterior to the fallopian tubesCorrelate with the male gubernaculumsThey extend laterally, cross the external iliac vessels, and enter the internal inguinal ring, and insert in the labia majora.Sampson’s artery, a branch of the uterine artery, runs along the length of the round ligament.
5Ligamentous Support Broad Ligament: Cardinal Ligament: Double reflection of the peritoneum, draped over the round ligaments.Cardinal Ligament:Found at the base of the broad ligament.Provides the main support for the uterus and cervix.It attaches to the cervix and extends laterally, connecting to the endopelvic fascia.
6Ligamentous Support Uterosacral Ligaments: Provide minor cervical support.Originate from the upper posterior cervix, travel around the rectum bilaterally, and fan out to attach to the 1st - 5th sacral vertebrae.
7Gynecologic Viscera Ovaries: Supported along the lateral pelvic sidewalls by the ovarian ligaments (attaching to the posteriolateral aspect of the uterus), the mesovarium (anastomotic region of the uterine and ovarian vessels), and the infundibulo-pelvic ligament (“The IP”), which are reflections of the broad ligament attaching the ovaries to the lateral pelvis.
8OvariesThey rest in the ovarian fossa, immediately adjacent to the iliac vessles and the ureters.They contain 3 distinct cell populations:Germ cellsStromal cells - tightly packed around developing follicles and secrete hormones.Epithelium
9Bladder and Rectum Don’t forget they are close by… Bladder is anterior to the uterus.Ureters originate in the renal calyces and insert in to the inferior bladder at the trigone.Careful attention to the ureters path in the pelvis is essential for dissection in gynecologic surgery.
11Key Points of the Ureter In the pelvis the ureter runs medial to and parallel with the internal iliac artery.Uterine artery crosses over the ureter (water under the bridge).The remaining 2-3cm of the ureter passes through the cardinal ligament into the bladder.
12RectumLies posterior to the uterus following the curvature of the sacrum.
13Blood SupplyMajority originates from the internal iliac artery (aka: hypogastric artery).Additional supply comes from the ovarian arteries, the inferior mesenteric artery, and the external iliac artery.
14Common iliac --> external and internal iliac External becomes the femoral arteryInternal iliac --> anterior and posterior divisionsPosterior division - rarely seen in pelvic surgery, has three branches that supply the gluteal region:Superior glutealIliolumbarLateral sacral arteries
15Anterior division: Uterine Vaginal Superior, Middle, and Inferior VesicalsMiddle and Inferior RectalObturatorInferior glutealInternal PudendalObliterated umbilical arteries
16During retroperitoneal surgery the primary branches identified are the: Superior vesical arteryUterine arteryObturator artery
17Ovarian arteries Ovarian veins: Originate directly from the aorta, inferior to the renal arteries.Most frequently identified at the IP ligament.Ovarian veins:Left ovarian vein drains into the left renal veinRight ovarian vein drains directly into the inferior vena cava.
18Lymph Drainage Cervical Cancer: Uterine Cancer: Ovarian Cancer: Drains 1st to the parametrial nodes --> obturator nodes --> pelvic nodes --> para-aorticUterine Cancer:Drains 1st to the pelvic nodes or para-aortic.Ovarian Cancer:Can metastasize to either the pelvic or para-aortic nodes.
19Pelvic SupportPelvic diaphragm is retroperitoneal and supports all the viscera.Composed of the:Levator ani group: puborectalis, pubococcygeus, and ileococcygeus.Coccygeous muscles
20Question #1 In a CT scan of the pelvis, the uterus is located: A) Posterior to the bladder and rectumB) Posterior to the bladder and anterior to rectumC) Anterior to the bladder and rectumD) Anterior to the bladder and posterior to the rectum
21AnswerB) Posterior to the bladder and anterior to the rectum.
22Question #2A 27 year-old woman is examined by her gynecologist. Upon rectal examination, a firm structure, directly in front of the rectum, in the midline, is palpated through the anterior wall of the rectum. The structure is:A) BladderB) Body of uterusC) Cervix of uterusD) Pubic symphysisE) Vagina
23Answer C) Cervix of uterus The cervix of the uterus is anterior to the rectumSince the cervix is the inferior part of the uterus that is protruding into the vagina, it should feel like a firm structure upon palpationAlthough the vagina is directly anterior to the rectum, it would not feel like a distinct and firm structure upon palpation.