Chapter 41- Normal Anatomy and Physiology of the Female Pelvis

Interstitial portion:

Pierces uterine wall at cornua

mesovarium ligament

Posterior fold of broad ligament; encloses ovary

Fallopian Tubes length:

12 cm; blood is supplied by ovarian arteries and veins

Uterine artery has branches that perforate serosa into myometrium forming arcuate vessels which can be seen sonographically.

Anechoic tubular structures in outer third of myome

The Bony Pelvis

Consists of four bone -Two innominate (coxal) bones - Sacrum -Coccyx

Retroversion:

Entire uterus tilted posteriorly

cardinal ligament

Extend across pelvic floor laterally; firmly supports cervix

uterosacral ligament

Extend from uterine isthmus downward, along side rectum to sacrum; firmly supports cervix

suspensory ligaments

Extends from lateral aspect of ovary to pelvic sidewall

Pelvic landmarks

External Landmarks -Mons pubis -Labia majora -Labia minora -Clitoris -Urethral opening -Vestibule of vagina

Retroflexion:

Fundus and body bent backward towards cervix

round ligament

Fundus to anterior pelvic sidewalls; holds uterus forward

infundibulum

Funnel-shaped lateral tube projects beyond broad ligament to overlie ovaries; "free edge" of the funnel has fimbriae

Isthmus:

Hardest part; lies lateral to uterus

broad ligament

Lateral aspect of uterus to pelvic sidewall

Vagina....

Lateral view of pelvis - relationship of anterior and posterior fornices to the cervix and vagina.

Anteversion:

Most common position; fundus and body tipped forward toward cervix

Dextroversion or levoversion:

Normal variant in absence of pelvic masses

Internal iliac arteries: ____ extend along posterior wall to perfuse pelvic structures (bladder, uterus, vagina and rectum)

(Hypogastric)

Ovaries

-Almond shaped -Variable positions

Ovaries......

-Anterior to internal iliac artery and vein -Medial to external iliac artery and vein

Bladder BASE:

-Anterior to vagina, superior surface related to uterus

The Pelvic Cavity and Perineum.......

-Anterior: Occupied by bladder, ureters, ovaries, fallopian tubes, uterus, vagina

The Pelvic Cavity and Perineum..

-Anterolateral walls formed by hip bones and obturator internus muscles, which rim ischium and pubis

Uterine Positions

-Anteversion -Dextroversion or levoversion -Retroversion -Retroflexion

The Pelvic Cavity and Perineum....

-Area below pelvic floor is perineum

Vagina & Cervix.

-Area of vaginal lumen surrounding cervix divided into four fornices -Arterial supply from vaginal and uterine arteries; drains into internal iliac vein

Ovaries.

-Attached at posterior aspect of broad ligament by mesovarium

Ovaries.....

-Blood drained by ovarian vein into IVC on right and into renal vein on left

uterine ligaments

-Broad -Mesovarium -Mesosalpinx -Round -Cardinal -Uterosacral -Suspensory -Ovarian

Ovaries Normal Anatomy...

-Central medulla composed of connective tissue containing blood, nerves, lymphatic vessels, and some smooth muscle at region of hilum

Vagina & Cervix..

-Cervix: projects into vaginal canal -Endocervix: Cervical canal; communicates with uterine cavity by internal os; vagina by external os -Exocervix: Continuous with vagina

Ureters..

-Coarse anteriorly and medially under base of broad ligament where crossed by uterine artery

Vagina

-Collapsed muscular tube that extends from external genitalia to cervix of uterus

Ovaries Normal Anatomy

-Consist of outer layer, or cortex, which surrounds central medulla

Ovaries Normal Anatomy.

-Cortex consists primarily of follicles in varying stages of development and is covered by layer of dense connective tissue, tunica albuginea.

Uterus.

-Covered with peritoneum except anteriorly below os where peritoneum reflected onto bladder

Ureters

-Cross pelvic inlet anterior to bifurcation of common iliac arteries

Ovaries....

-Dual blood supply; receives blood from ovarian artery and uterine artery

Ovaries.......

-Ellipsoid shape with long axis oriented vertically

Ovaries...

-Fossa is bounded by external iliac vessels, ureter, obturator nerve

Uterus

-Hollow, pear-shaped organ -Divided into fundus, body, cervix -Usually anteflexed and anteverted

Ovaries Normal Anatomy.....

-Hormones responsible for producing and maintaining secondary gender characteristics, preparing uterus for implantation of fertilized ovum, development of mammary glands in female

Fallopian Tubes

-Infundibulum -Isthmus -Ampulla -Interstitial portion

endometrium

-Inner mucous membrane, glandular portion of uterine body

Cervix..

-Is a continuous ring-shaped space with posterior fornix running deeper than its anterior counterpart

True Pelvis

-Is situated inferior to caudal portion of parietal peritoneum -also considered the pelvic cavity

The Pelvic Cavity and Perineum......

-Known as pelvic diaphragm

Ovarian Ligaments.

-Laterally by suspensory (infundibulopelvic) ligament, extending from infundibulum of fallopian tube and ovary to sidewall of pelvis

Muscles of the Pelvis..

-Levator ani: Pelvic floor (diaphragm) -Coccygeus: Posterior pelvic floor (diaphragm)

Ovaries..

-Lie in ovarian fossa (also known as fossa of Waldeyer - Peter Callen)

Vagina.

-Lies posterior to urinary bladder and urethra, anterior to rectum and anus

Bladder APEX:

-Located posterior to pubic bones

Ovaries........

-Location highly variable as ligaments loosen, especially after pregnancy

The Pelvic Cavity and Perineum...

-Lower margin of pelvic cavity, pelvic floor, formed by levator ani and coccygeus muscles

Vagina...

-Measures approximately 9 cm in length; is longest along posterior wall

Uterine Size-Body of uterus::

-Medial to broad ligaments and uterine vessels -Uterine cavity is funnel-shaped in coronal plane; "slitlike" in sagittal plane

The Abdominal Wall

-Muscles extend superiorly from xyphoid process to symphysis pubis inferiorly

myometrium

-Muscular middle layer of uterus composed of thick, smooth muscle supported by connective tissue

Vagina..

-Normally directed upward and backward, forming 90-degree angle with uterine cervix

Muscles of the Pelvis....

-Obturator internus: Anterolateral pelvic sidewall

ovarian ligament

-Ovarian: Extends medially from ovary to uterine cornua

Ovarian Ligaments

-Ovaries supported medially by ovarian ligaments, originating bilaterally at cornua of uterus

Ovarian Ligaments..

-Ovary also attached to posterior aspect of broad ligament via mesovarium

Muscles of the True Pelvis

-Piriformis muscles -Obturator internus muscles -Muscles of pelvic diaphragm -Coccygeus muscles -Levator ani: 3 muscles which are -Pubococcygeus muscles -iliococcygeus muscles -puborectalis muscles

Muscles of the Pelvis...

-Piriformis: Posterolateral wall

Uterine Size-Body of uterus:

-Posterior to vesicouterine pouch and superior surface of bladder -Anterior to rectouterine pouch (of Douglas), ilium, colon

Cervix.

-Posterior vaginal wall attaches higher on cervix, and fornices are blind pockets formed by inner surface of vaginal walls and outer surface of cervix.

The Pelvic Cavity and Perineum

-Posterior wall formed by sacrum and coccyx

The Pelvic Cavity and Perineum.....

-Posterior: Occupied by rectum, colon, ileum

The Pelvic Cavity and Perineum.

-Posterolateral wall formed by piriformis and coccygeus muscles

Uterine Size

-Premenarchal: 1.0 - 3.0 cm long by 0.5-1.0 cm wide -Menarchal: 6.0 - 8.0 cm long by 3.0-5.0 cm wide -With multiparity: Increases size by 1.0-2.0 cm -Postmenopausal: 3.5 - 5.5 cm long by 2.0-3.0 cm wide

Ovaries Normal Anatomy....

-Produce reproductive cell—ovum, two known hormones: estrogen, secreted by follicles, and progesterone, secreted by corpus luteum

Cervix

-Protrudes into upper portion of vaginal canal forming four archlike recesses called fornices

Muscles of the False Pelvis

-Psoas major -Iliacus muscles -Iliacus muscle joins the psoas muscle to form the iliopsoas muscle along the sidewall of the false pelvis.

Muscles of the Pelvis

-Psoas major: Pelvic sidewall -Iliacus: Pelvic sidewall

Bladder NECK:

-Rests on upper surface of urogenital diaphragm; inferolateral surfaces relate to retropubic fat, obturator internus, levator ani muscles, pubic bone

Uterus...

-Round ligaments hold uterus in anteverted position

Ureters...

-Run anterior and lateral to upper vagina to enter posteroinferior bladder

Ureters.

-Run anterior to internal iliac arteries and posterior to the ovaries

perimetrium

-Serous outer layer of uterus; serosa

Uterus..

-Supported by levator ani muscles, cardinal ligaments, uterosacral ligaments

Ovaries Normal Anatomy..

-Tunica albuginea surrounded by single, thin layer of cells known as germinal epithelium

Vagina & Cervix

-Vagina: extends upward and backward from vulva -Upper half lies above pelvic floor -Lower half lies within perineum

Mesosalpinx liagment

Upper fold of broad ligament; encloses fallopian tube

Ampulla:

Widest part of tube where fertilization typically occurs

Blood is supplied to ____ by radial arteries in base of endometrium, where straight and spiral arteries branch off to supply the zona basalis of endometrium.

endometrium

Common iliac arteries bifurcate into ____?

external iliac and internal iliac arteries:

Layers of the uterus

perimetrium, myometrium, endometrium

Blood from ____ is shed during menses.

spiral arteries

Bony pelvis is divided into two regions

true and false -by oblique plane that passes through pelvic brim. This plane division passes from superior border of sacrum to superior margin of pubic symphysis and corresponds to iliopectineal line.