ANATOMY OF FEMALE INTERNAL GENITAL ORGANS.pptx

This ppt describes the female internal genitalia along with the applied aspect of each of them which will be helpful to ug and pg students of medical fraternity. This ppt has images along with the description which will aid in better understanding of the topic.

1. Anatomy of internal female genital tract Dr. Shivani Siddhpura M.S.ObsGyn

2. It consists of:

3. Development Ovary develops from genital ridge & mesonephros. Uterus, cervix, fallopian tubes and upper 1/3 rd of vagina develops from mullerian ducts/ paramesonephric ducts. Lower 2/3 rd vagina develops from urogenital sinus.

4. Vagina Anatomy: Musculo-membranous tube connecting uterine cavity to introitus at vulva. Lowermost part of internal genital tract. Provides canal for menstrual blood outflow, coitus & childbirth. The canal is directed upwards and backwards forming an angle of 45° with the horizontal in erect posture. 4 walls: 1 anterior, 1 posterior & 2 lateral walls. 4 fornices : 1 anterior, 1 posterior and 2 lateral. Posterior fornix is the deepest and it forms the recto-uterine pouch/ Pouch of Douglas/ cul-de-sac.

5. Clinical Significance: The internal pelvic organs can be palpated through the fornices . The posterior fornix (pouch of douglas ) provides surgical access to peritoneal cavity for culdocentesis and for colpotomy. Anterior Relations: Upper 1/3 rd : bladder & ureter Middle 1/3 rd : bladder neck & trigone Lower 1/3 rd : urethra Posterior Relations: Lower 1/3 rd : perineum Middle 1/3 rd is separated from rectum by rectovaginal septum and upper 1/3 rd is separated from rectum by recto-uterine pouch.

6. Lateral Relations: Upper 1/3 rd : Cardinal ligaments, perimetrium, parametrium with ureter and uterine artery ~cm from lateral fornix. Middle 1/3rd: levator ani Lower 1/3 rd : bulbospongiosus muscles, vestibular bulbs and Bartholin’s glands.

7. Structure: 4 layers. Non-keratinised stratified squamous epithelium. Vaginal Secretion: Watery transudate of exfoliated vaginal epithelial cells, proteins & Doderlein’s bacilli. Doderlein’s bacilli: gram positive rods which flourish in acidic medium. They convert glycogen in vaginal mucosal cells to lactic acid which lowers the vaginal pH. Normal vaginal pH in reproductive period: 4 to 5 (acidic) Before puberty & menopause: alkaline, therefore prone to vaginal infections. Positive Schiller’s test: normal Negative Schiller’s Test: menopausal & cancerous cells.

8. Applied anatomy of vagina Perineal body is one of the chief supports of pelvic organs. It is a fibromuscular node to which ten muscles are attached (2 superficial transverse perinei , 2 deep transverse perinei , 2 pubococcygeus part of levator ani, 2 bulbospongiosus , single sphincter ani externus & unstriped fibres of longitudinal coat of anal canal). Damage to the perineal body often leads to prolapse of the uterus & of other pelvic organs. Colpotomy & Colporrhaphy: Posterior colpotomy is dine to drain the pus from the POD.

9. Uterus The uterus is a hollow pyriform muscular organ situated in the pelvis between the bladder in front and the rectum behind. Position: Anteversion and anteflexion. The uterus usually inclines to the right (dextrorotation) so that the cervix is directed to the left (levorotation) and comes in close relation with the left ureter. Measurements: 8 cm long, 5 cm wide at the fundus and its walls are about 1.25 cm thick. Its weight varies from 50 gm to 80 gm.

10. Parts of Uterus: 1. Body/ Corpus: further divided into fundus (convex upper part above insertion of fallopian tube), body (between insertion of fallopian tube & isthmus) & cornua (area from where fallopian tubes emerge). Round ligament, Fallopian Tube & ovarian ligament are attached to cornua . 2. Isthmus: 0.5cm constricted part. It forms the lower uterine segment during pregnancy & caesarean delivery is performed through it. 3. Cervix: Supra-vaginal part is covered by peritoneum posteriorly. The ureter is 1.2cm away from the supravaginal cervix. It has a cervical canal which extends from internal os to external os . External os in nulliparous woman is circular, in multiparous is transverse slit-like. 4. Cavity: 3.5-4cm long, triangular in shape with apex below.

11. Relations: Anterior: Peritoneum covers only upper part of the uterus upto the level of internal os . It helps the surgeon to identify lower segment while performing LSCS. Posterior: whole posterior surface is covered by visceral peritoneum with its lower part forming POD which contains loops of ileum. Lateral: 2 layers of broad ligament through which the uterine vessels and ureter pass ~1.5cm away. Secretion: The endometrial secretion is scanty and watery. Secretion of the cervical glands is alkaline and thick, rich in mucoprotein, fructose and sodium chloride.

12. Layers of Uterus: Perimetrium: Outer serous layer covers the entire surface of uterus except the lateral walls. Myometrium: Dense network of smooth muscle cell fibres arranged in criss-cross manner. During pregnancy, it is arranged in 3 layers: outer longitudinal, middle spiral and inner circular. Endometrium: Varies in thickness from 0.5 – 10mm depending on the phase of menstrual cycle. Consists of a single layer of columnar epithelium & mesenchymal stroma. The superficial layer responds to cyclical hormone changes. It converts to decidua during pregnancy.

13. Applied Anatomy of Uterus Uterus is site of implantation of blastocyst and development of fetus . Intra-uterine contraceptive device (IUCD) is used to prevent implantation of blastocyst. Uterus is the common site for formation of fibroids and has a etiological role in AUB. Mullerian Anomalies: Developmental defect of the mullerian ducts.

14. Cervix Cervical stroma is made up of collagen, elastin & proteoglycan with very few smooth muscle cells. 2 parts: Endocervix: part inside external os , with columnar epithelium secreting mucus which forms the mucous plug in pregnancy. Ectocervix: part outside external os , lined by non-keratinised stratified squamous epithelium. Therefore, external os is the site of squamo -columnar junction.

15. Applied Anatomy of CErvix The squamo -columnar junction at external os is the the functional landmark of transformational process i.e. metaplasia. Transformation zone (TZ): Area between the original SCJ and the new SCJ where the columnar epithelium (ectropion) has been replaced and/or is being replaced by the new metaplastic squamous epithelium. Age & hormonal status are the most important factors influencing the location of SCJ on the cervix. HPV Infections affecting the transformation zone may lead to pre-invasive lesions and malignancy.

16. The TZ is the site of origin for > 90% of precancerous lesions also called squamous intraepithelial lesions (CIN) and cancers. Hence, it is the site from where sample is taken using Ayre’s spatula for pap smear as a routine screening for cervical cancer in all women aged >40 years.

17. Fallopian Tubes Intramural: narrowest part, 1.25cm length, 1mm diameter. Isthmus: straight to tortuous part, 2.5cm length, 1-2mm diameter. Site of TL Ampulla: Tortuous & wide, 5cm in length with lumen measuring 1-2mm medially & 6mm laterally. Infundibulum: funnel shaped opening, 1.25cm length, 3mm diameter. Has various processes called fimbria to pick up the ovum during ovulation.

18. Structure: It consists of three layers: Serous: consists of peritoneum on all sides except along the line of attachment of mesosalpinx Muscular: arranged in two layers outer longitudinal and inner circular Mucous membrane: three different cell types and is thrown into longitudinal folds. ( i ) Columnar ciliated epithelial cells that are most predominant near the ovarian end of the tube. These cells compose 25% of the mucosal cells (ii) Secretory columnar cells are present at the isthmic segment and compose 60% of epithelial cells (iii) Peg cells are found in between the above two cells. They are the variant of secretory cells.

19. Function: Site for fertilization at ampulla. Transport of gametes. Ovum stays in FT for 3 days. Tubal transport of ovum & zygote by peristalsis & mucosal ciliary function. Tubal secretion contains pyruvate for nurturing the zygote. Clinical Significance: Implantation may rarely occur in the fallopian tube which is called ectopic pregnancy. Inflammation of the FT is called Salpingitis. The most common cause on infertility in the female is called tubal blockage which may be caused by infection or adhesions. For purpose of family planning, a woman can be sterilised by ligating or excising a segment of FT (isthmic region most commonly) on both sides.

20. Ovary Located one on either side. Solid, flat, ovoid gonad. Responsible for maturation, storage and release of germ cell (ovulation) and production of sex hormones (steroidogenesis) mainly during reproductive period of a woman. Measure 3 x 2 x 1cm and weighs 5 – 10gm during reproductive period. Position: Usually situated in the upper part of pelvic cavity in a slight depression on the lateral wall of pelvis called the ovarian fossa of Waldeyer . Each ovary presents two ends—tubal and uterine, two borders—mesovarium and free posterior and two surfaces—medial and lateral.

21. Ovarian Fossa of Waldeyer : Bounded anteriorly by external iliac vessels, posteriorly by ureter & internal iliac vessels and inferiorly by Fallopian tubes in the upper free margin of the broad ligament.

22. Ovaries are intraperitoneal structure. Each ovary is connected to posterior layer of broad ligament by mesovarium (anterior border formed by peritoneal fold). Posterior border is free and is related to the tubal ampulla. It is separated by the peritoneum from the ureter and the internal iliac artery. The medial pole is attached to uterine cornua by ovarian ligament. Laterally it is connected to pelvic wall by infundibulopelvic ligament which contains ovarian vessels & nerves.

23. Structure: Surface epithelium: Single layer of cubical cells called germinal epithelium. Cortex: Composed of Stromal cells and ovarian follicles which are the functional unit of vary scattered in the cortex. All forms of ovarian follicles can be seen in the cortex and they secrete estrogen & progesterone hormones and produce ovum. Tunica Albuginea, outermost portion of cortex is dull and white. Medulla: It is the central loose connective tissue which is composed of large number of arteries, veins, nerves and few lymphatics.

24. Applied anatomy of ovary In cases of infertility, ovulation can be determined by serial ultrasonography. PCOS: The developmental arrest of the ovarian follicles may result in formation of multiple, small ovarian cysts which along with menstrual cycle irregularities and androgen excess can lead to PCOS. Ovaries are the commonest site in abdomen for development of endometriosis. The endometriotic cysts in ovaries are called chocolate cysts.