Anatomy of female pelivs introduction for ob/gyne wardpptx

introduction and revetion before we start ob/gyne ward so you remember anatomy

1. Anatomy of female pelivis By Dr.G / senbet

2. Introduction Knowledge of the major features of the female pelvis is essential for:- Understanding the process of reproduction and child bearing Understanding the effect of pathologic processes on the pelvis and on the woman’s health The Structure and function of the genital organs vary significantly with age and the hormonal status of the woman

3. The bony pelvis (Latin- basin) It is part of the trunk below the abdomen proper It consists of false and true parts which are separated by planes of the superior aperture/ plane/ of the less pelvis This plane passes from the sacral promontory to the upper surface of the pubic symphysis . It separates the lower most part of the abdomen proper i.e greater or false pelvis from the less or true pelvis. Child birth takes place through this pelvic cavity. The less /true/ pelvis has an upper aperture, a cavity and a lower aperture

4. Skeletons of the pelvis These are 4 bones:- Sacrum and coccyx – from behind The two innominate- each composed of the ileum, ischium and pubis ~ from lateral and front sides. These bones are held together by the sacroiliac, symphysis pubis and the sacro -coccygeal joints. Union of the pelvis and the vertebral column stabilizes the pelvis and allows weight to be transmitted to the lower extremities. Sacrum- consists of 5 fused vertebrae. Promontory – the anterior superior border of the 1st sacral vertebra. It protrudes slightly in to the pelvic cavity.

5. Contd ……….. The pelvis is described as having four imaginary planes: 1. The plane of the pelvic inlet—the superior strait. 2. The plane of the pelvic outlet—the inferior strait. 3. The plane of the mid pelvis—the least pelvic dimensions. 4. The plane of greatest pelvic dimension—of no obstetrical significance.

6. Contd ………… 1 Plane of the pelvic inlet It is bordered by: the pubic crest---- anteriorly iliopectineal line of the Innominate bones laterally and by the sacral promontory posteriorly

7. Contd ………. 2 Plane of the pelvic outlet It is formed by two triangular planes with a common base at the level of the ischial tuberosities . The Anterior triangle is bordered by the subpubic angle at the apex, pubic rami on the sides and bituberous diameter at the base. The posterior triangle is bordered by the sacro -coccygeal joint at its apex and the sacrotuberous ligaments laterally and the bituberous diameter at its base.

8. Contd ……… 3. Plane of greatest diameter (dimension) It is the largest part of the pelvic cavity not important from clinical point of view. 4 . Plane of the least diameter It is the most important diameter from clinical stand point, because the most instances of arrest occur at this level. It is bordered by the lower edge Of the pubis anteriorly, the ischial spines and sacrotuberous ligaments laterally and the lower sacrum posteriorly. Ischial spines >>>>> land mark for pudendal nerve block

9. Pelvic diameters These diameters represent the amount of space available at each level. The key measurements for assessing the capacity of the maternal pelvis include:- The bispinous diameter The obstetric conjugate of the inlet The bituberous diameter The posterior sagittal diameter at all levels The curve and length of the sacrum The sub pubic angle.

10. The Pelvic inlet It has 5 important diameters:- 1. Anterior posterior (A-P) diameters Described by one of the 2 measurements a ) The true conjugate (anatomic conjugate ) measure about 11.5cm It is the anatomic diameter It extends from the middle of the sacral promontory to the superior surface of the pubic symphysis b) The obstetric conjugate ( 10.5cm ) It represents the actual space available for the presenting part of the fetus to descend.It extends from the middle of the sacral promontory to the closest point of the convex posterior surface of the symphysis pubis

11. Contd ………. 2 . Transverse diameter (13.5cm) It is the widest distance between the ilio pectineal lines. 3 . Oblique diameters (12.5cm) Each oblique diameter extends from the sacroiliac joint to the opposite ilio pectineal eminence 4.The posterior sagittal diameter extends from the A-p and transverse intersection to the middle of the sacral promontory.

12. Plane of least diameters (mid plane); It has 2 important diameters 1 . A-p diameter(12cm) extends from the lower border of the pubis to the junction of the 4th and 5th sacral vertebrae 2. Transverse ( Bispinous )- diameter (10.5cm)- extends between the ischial spines

13. The pelvic outlet It has 3 important diameters 1)The anatomic A-p diameter (9.5cm)- extends from the inferior margin of the pubis to the tip of the coccyx 2)The obstetric A-p diameter (11.5cm)- extends from the inferior margin of the pubis to the sacro coccygeal joint. 3)The transverse ( bituberous ) diameter (11cm)-extends between the inner surfaces of the ischial tuberosities .

14. Pelvic shapes Based on the general bony architecture the pelvis is classified into 4 basic types 1.Gynecoid: - The classic female type of pelvis It is found in 50% of women round at the inlet, with the widest transverse diameter (TD) only slightly greater than the A-P diameter . Side walls are straight Ischial spines are of average prominence Well curved sacrosciatic notch Well curved sacrum Spacious subpubic arch with an angle of around 90 degrees

15. 2. Android This is a typical male type Approximately 30% of women have this type of pelvis The inlet is triangular Side walls are convergent with prominent spines Shallow sacral curve Long and narrow sciatic notch. Narrow subpubic arch

16. 3 . Anthropoid This pelvis resembles that of the anthropoid ape. Found in approximately 20% of women . A-p Diameter is much lager than T – D which creates a long narrow oval shape at the inlet

17. 4 .Platy pelloid Described as a flattened gynecoid pelvis Found in only 3% of women. Short A-P and wide transverse diameters creating an oval shaped inlet

18. II. Perineum Its boundaries are: a) Levator ani Muscle- superiorly b) The skin between the thighs- inferiorly C)Anteriorly it extends to the symphysis pubis and the inferior borders of the pubic bones. D) Posteriorly , it is limiter by the schial tuberosties , sacro tuberous ligaments and coccyx. The superficial and deep transverse perineal muscles cross the pelvic out let between the two ischial tuberosity and divide the space in to : - The urogenital triangle- anteriorly and -The anal triangle posteriorly

19. Contd ….. The muscle that span the pelvic floor collectively called pelvic diaphragm w/c include Levator ani muscle Coccygeus muscle Superior and inferior investing fascia

20. Contd ……… Perineal membrane- a fibromuscular sheet stretches across the pubic arch. It is pierced by the : Vagina Urethra Vessels to various structures Dorsal clitoris nerve - Inferior surface of the urogenital diaphragm is covered by Crura (Legs) of the clitoris Vestibular bulbes The gereater vestibulles ( Bartholins ) glands Superficial perineal muscles

21. III External genitalia Collectively referred to as the vulva or the pudendum It includes : The mons pubis ( Veneris ) Labia majora Labia minora Clitoris The vestibule The fourchette The perineum

22. Contd ………… Mons veneris or pubis A pad of subcutaneous fatty tissue in front of the pubis. It is covered by the pubic hair in an inverted triangular fashion as opposed to the triangular fashion of hair growth in the male.

23. Contd ………… Lamia Majora Elevation of skin and subcutaneus tissues. Most prominent features of the vulva. Are hair - covered folds of skin They form the lateral boundaries of the vulva Each Labium majus fuses posteriorly with its counterpart and they form the posterior commissure. They contain ; Sebaceous glands ,and Sweat glands Hair follicles and adipose tissue Venous plexus- form hematoma if injured Are homologous with the scrotum in the male.

24. Contd ………. Labia minora It is often scarcely noticeable and it’s a leaf - like flaps of 2-3cm in length. Lie medially within the labia majora Are 2 skin folds Are devoid of fat & hair follicles Anteriorly they are divided in to 2 folds to enclose the clitoris. The posterior pair of folds attaches to the inferior surface of the clitoris and they unite to form the Frenulum of the clitoris. The anterior pair unite like a hood (hat like) over the clitoris to form the prepuce of the clitoris. Posteriorly they extend to form the fourchette . They have rich supply of venous sinuses and nerves. Are homologous with the anterior aspect of the penis

25. Contd …….. Clitoris It lies just in front of the urethra It is a small cylindrical erectile structure It consists of; Glans Body Crura - 2 legs Its body is composed of a pair of corpora cavernosa , which extends superiorly for a distance of several centimeters and divides in 2 crura , attached to the under surface of the either pubic ramus It’s homologous with the penis in the male

26. Contd ……….. Fourchette : - Posterior junction of labia minora just above the perineal body . Vestibule :- The space between the labia minora in to which the urethra and the vagina open It is a triangular in shape It is bounded by:- Clitoris-anteriorly The fourchette –posteriorly Labia minora – on either side

27. Contd ……. There are 5 openings into the vestibule; 1) Urethral opening anterior to the vaginal orifice ≈ 2-3 cm posterior to the clitoris 2 ) Barthalin’s glands(2) are on each side 3 skene gland just in front of the urethra 4 ) Vaginal opening – posterior to the urethral orifice. The vaginal opening is nearly closed by the labia minora in virgins and in nulli porous women In parous and in old women the vaginal opening is exposed. The vaginal opening is incompletely closed by a septum of mucuous membrane called the hymen The hymen is represented in sexually active and in parous women by a circle of carunculae myrtiformes around the vaginal introitus .

28. Contd ….. Hymenal membrane may take many forms:- Infantile Cribriform plate with many small openings or holes Crescent or half moon shape circular or annular shape septated vertical shape may even be imperforated Hymenal shape and opening vary and depend on age , parity and sexual experience. In parous women and in post coital state the tags of the hymenal integument are termed as carunculae myritformes .

29. Iv Bartholin‘s glands These are superficially situated on the perineal pouch on each side on the posterior one third of the vestibular bulb. They secrete alkaline mucous during sexual excitement (arousal) which helps in lubrication. Each gland has its duct which opens into the hymen . They are homologous to the bulbourethral gland in the male. Often the openings of these glands, host gonococci and cause abscesses and retention cysts.

30. V Perineal body It is a pyramidal shaped tissue Here meet the pelvic floor, perineal muscles and pelvic fascia. It is between the vaginal and anal canal

31. Vulvar or pudendal blood supply Arteries: - branches from the internal pudendal arteries They are:- Labial artery Transverse perinial artery Artery to the vestibular bulb Deep and dorsal arteries to the clitoris Superfical and deep pudendal and femoral arteries

32. Contd ………. Veins – Vulvar veins form plexuses and they drain in to :- Pudendal veins Vesical veins Vaginal plexus veins Long saphenous veins

33. Nerve supply to the Vulva Cutaneous branches from :- - Ilioinguinal nerve - Genital branches of genito femoral nerve - perineal branch of the posterior cutaneous femoral nerve of the thigh -labial and perineal branch of the pudendal nerve

34. Internal female genital organs These are:- 1. The vagina 2. The uterus 3. The fallopian /uterine/ tube 4. The ovaries 1. The vagina It is a fibro muscular membranous canal It is a flattened tube It extends from the hymenal ring at the introitus up to the fornices that surround the cervix It is devoid of mucous glands and hair follicles

35. The vaginal wall is composed of 4 Layers 1) Inner most mucus membrane. This is non - keratinized stratified squamous epithelium 2) Sub mucous Layer 3) Deep to the vaginal epithelium are the muscular coats of the vaginal (inner circular) and (an outer longitudinal) smooth muscle layer 4) Fibrous coat

36. The vaginal has 4 walls 1) Anterior wall – over the posterior bladder 2) Posterior wall-over the rectum 3) 2 lateral walls The vagina averages about 7cm from anteriorly and 8-9 cm in length posteriorly. It size varies with age, parity and status of ovarian hormonal function. The vagina communicates the uterine cavity to the externum at the vulva. The uterine cervix projects at right angle through the anterior vaginal wall Fornix ( plu - fornices ) This is a cleft formed by the cervical projection into the anterior vaginal vault

37. Vagina has 4 fornices These fornices are 4 1. Anterior fornix 2. posterior formix 3. 2 lateral fornices The vagina has small but enough secretions to keep it moist The vaginal secretion is normally Acidic Its PH ranges between 4.5-5.5 in reproductive age groups Most important microorganism is the DODER LELN’S MYCOBACILi . They convert glycogen from exfoliated squamous cells into LACTIC acid. The immediate proximity of the posterior formix of the vaginal to the pouch of Douglas allows easy access to the peritoneal cavity from the vagina by either culdo centesis or colpotomy E.g –to drain pelvic becess

38. Functions of the vagina Excretory channel for menstrual blood and for utero cervical secretions. It is the birth canal for the fetus during vaginal delivery It is an organ of copulation or organ of sexual intercourse

39. Vaginal arteries are from:- Cervico vaginal branch of the uterine artery. Vaginal artery from a branch from the internal iliac artery. Middle rectal and internal pudendal arteries. All these arteries (1-2) anastemose and form 2 azygous arteries of an anterior and posterior branches. The veins of the vagina drain into the interal lilac veins

40. The uterus It is a hollow pyrform muscular organ It is between the bladder /anterior/ and the rectum (posterior) Normally it is an anteverted and ante flexed organ It consists of the cervix, the isthmus and the uterine corpus, which are joined by the isthmus The isthmus represents a transitional area wherein the endocervival epithelium changes into the endometrial lining. In late pregnancy the isthmal area elongates and is referred to as the lower uterine segment Uterine dimensions are 1. Length 7.5-9cm 2. width 5cm 3. Thickness 1-1.25 cm

41. Parts of the uterus 1. Body (corpus ) – between the opening of the uterine tubes and the isthmus. The uterine fundus is the part above the insertion (Opening ) of the utenine tubes . 2.The isthmus- a constricted part between the body and the cervix. It is ≈ 0.5cm-1cm in length During late pregnancy and labour it is referred as to the lower segment.

42. Contd ……….. 3 . The cervix- A cylindrical shaped most lower part of the uterus. - it is 2-3 cm is length - It has 2 parts Its openings are:- The internal OS The external Os

43. Contd ………. Portio vaginalis is surrounded by the fornices and it is covered with a non – keratinizing squamous epithelim.At about the external cervical OS, the squamous epithelium, covering the exocervix changes to a simple columnar epithelium, forming the squamo columnar junction. It is called also the trans formation zone. The cervical canal is lined by an irregular simple columnar epithelium which extends into the stroma forming crypts or cervical glands – Nabothian glands.

44. The uterine corpus:- It is a thick pearl-shaped organ. It is flattened anteri posteriorly It consists of largely interlacing Smooth muscel fibers. The uterine wall has 3 Layers: 1. The perimetruim – This is the serous coat over most of the lower outer uterine surface. 2. Myometrium – This is a thick bundle of smooth (interlaced) muscles which are arranged in circular ( inner) and longitudinal / Outer/fashion 3. 3.Endometrim- the inner lining of the uterine corpus. It varies from 2 to 10mm in thickness depending on the stage of the menstrual cycle.

45. Attachments of the uterus Several ligaments extend from the uterus to pelvic sidewall . 1 ) Two round Ligaments Each is attached on the anterior surface of the uterus just in front of the uterine tubes. Each round ligament passes to the pelvic side wall in a fold of the broad ligament and it goes to the inguinal canal and ends in the labium majus on e ach side These ligaments are of liltle supportive value but they help to keep the uterus anteverted

46. Contd ……… 2) Two uterosacral ligaments :- These are condensations of the endopelvic fascia which arise from the sacral surface. From the sacral surface they come out on the either side of the rectum and they insert in to the poster inferior portion of the uterus at about the level of the isthmus. These ligaments contain fibers of the sympathetic and Para sympathetic nerves which supply the uterus. These ligaments support the uterus very well and they preclude the development of an enterocele .

47. Contd ………. 3) Two cardinal ligaments:- They are the other supporting structures of the uterus that prevent uterine prolapse. They extend from the pelvic fascia on the lateral pelvic walls . They insert in to lateral portion of the cervix and the vagina. Superiorly they too reach the level of the isthmus. 4 ) The pubo cervical ligaments :-Pass anteriorly around the bladder to the posterior surface of the pubic symphysis .

48. There are 4 peritoneal folds 1. Vesico uterine fold - anteriorly This is reflected from the level of the uterine isthmus on to the bladder. 2 . Recto uterine fold:- Posterioly - This pass from the posterior wall of the Uterus to the upper 4th of the vagina and Then on to the rectum - These fold form the cul-desac , called the pouch of Dougulas . 3 . The two broad ligaments – Bilaterally - Each passes from the side of the uterus to the lateral wall of the pelvis . - Between the 2 leaves of each broad ligament are contained the uterine tube, the round ligament ,ovarian ligament, nerves, blood vessels and lymphatic.

49. Uterine blood supply Arterial supply comes mainly from the 2 uterie arteries which are from the anterior division of the internal iliac artery. Other sources are vaginal and ovarian arteries. Veins drain along side their arterial course in to the internal iliac veins.

50. The fallopian /uterine/ tubes They are called also oviducts. They are muscular tubes, about 10cm in length. They connect the uterine cavity with the peritoneal cavity . They are endorsed in the medial 4/5 of the broad ligament. These tubes are lined by a ciliated columnar epithelium that is thrown into branching folds.

51. Contd ……… Each uterine tube has 4 parts:- Intramural or interstitial – segment of the tube within the uterine wall The isthmus – Non - mobile portion of the tube with fairly narrow lumen. - It is superior to the round ligament and anterior to the ovarian ligament 3 . The ampulla - the wide tortuous part and site of fertilization 4. The fimbrial end:- the most lateral portion of the tube. Each uterine tube has an abdominal ostium /opening/. Each ostium is surrounded by radiating fimbria. As the uterine tube proceeds laterally, at least one longer fimbrium is attached to the ovary- ovarian fimbrium . This fimbriated portions of the tube are suspended from the broad ligament by the mesosalpinx and are quite mobile. This mobility of the fimbriated end of the tube plays role in fertility

52. The ovaries These are oval, flattened, compressible and paired sex glands (organs). Each ovary is approximately 3cm long, 2cm wide and 1cm thick. Each ovary is situated on the superior surface of the broad ligament, suspended between the ovarian ligment medially and the suspensor ligament of the ovary or infundibulopelvic ligament laterally and superiorly. Each ovary is attached to the uterus by the utero- ovarian ligament Each ovary occupies a position in the ovarian fosse of Waldeyer , as hallow depression on the lateral pelvic wall, posterior to the ureters and hypo gastric vessels

53. Contd ……….. Each ovary is covered by a single layer of germinal epithelium. The serosal covering and the tunica anlbuginea are quite thin ,so that developing follicles and the corpora lutea / lutea body/are readily visible Ovarian substance has a cortex/outer layer/and a medulla /inner most layer/.

54. The cortex of the ovary This is a functional layer It contains: 1.Primordial follicles 2. Mature / Graffin / follicles 3 . Corpus luteum 4. Atretic follicles 5 . Corpus albcans

55. The medulla of the ovary It consist of . Connective tissue, Muscle cells , Blood vessels,Nerves , Hilary cells Blood Supply of the ovaries : This is provided by the long ovarian arteries. They arise from the abdominal AORTA immediately below the renal arteries. The vessels course downward and each crosses laterally over the ureter at the level of the pelvic BRIM giving branches to the ureter and uterine tube The ovaries also receive blood supply from the uterine artery

56. contd Veins drain From the right ovary directly into the inferior vena cava From the left ovary into the left real vein. Ureters Ureters extend 25 to 30 cm from the respective renal pelvis to their insertion into the bladder at the trigone . Each ureter descends under the peritoneum, crossing the pelvic brim beneath the ovarian vessels just anterior to the Bifurcation of the common iliac artery.

57. Lymphatic drainage of the genital organs From the vulva and the vagina to the Inguino - femoral lymph nodes and then to the external iliac chains From the cervix It takes place through the parametra (cardinal ligaments) to the pelvic nodes (the hypo gastric, obturator and external iliac groups) and finally to the common iliac and para -aortic chains. From the endometrium – it goes through the broad ligaments and infundibulo - pelvic ligaments to the pelvic and aortic chains. From the ovaries the lymphatic drainages pass via the infundibulo pelvic ligaments to the perlvic and Para aortic nodes

58. Pelvic Innervation Predominantly autonomic ( symphatetic and parasymphatetic ). Symphatetic (T10-L2). Parasymphatetic (S2-S4)

59. Reference: Williams gynecology 3 rd Williams obstetrics 25th Uptodate 2018