Week 1 - Normal A&P of Female Pelvis - Ch.41

External Pelvic Landmarks

• Mons pubis

• Labia majora

• Labia minora

• Clitoris

• Urethral opening

• Vestibule of vagina

Four bones of the Bony Pelvis

• Two innominate bones (ilium + ischium + pubic bones)

• Sacrum

• Coccyx

Which bones make up the innominate bones?

Ilium, ischium, and pubis

Pelvis

divided into two continuous compartments: true pelvis and false pelvis

True Pelvis (Pelvic Cavity)

situated inferior to caudal portion of parietal peritoneum

Posterior wall of Pelvic Cavity

formed by sacrum and coccyx

Posterolateral wall of Pelvic Cavity

formed by piriformis and coccygeus muscles

Anterolateral walls of Pelvic Cavity

formed by hip bones and obturator internus muscles

Pelvic Floor (Pelvic Diaphragm) of Pelvic Cavity

formed by levator ani and coccygeus muscles

Pelvic Floor (Pelvic Diaphragm)

lower margin of pelvic cavity

Perineum

area below pelvic floor

Pelvic cavity

contains the urinary bladder, uterus, ovaries, fallopian tubes, vagina, and rectum

Posterior of Pelvic Cavity

occupied by rectum, colon, ileum

Anterior of Pelvic Cavity

occupied by bladder, ureters, ovaries, fallopian tubes, uterus, vagina

Muscles of False Pelvis

Psoas major, Iliacus, and Iliopsoas muscles

Psoas major

pelvic sidewall muscle of false pelvis

Iliopsoas

a muscle formed by psoas and iliacus joining together

Iliacus

pelvis sidewall muscle of false pelvis

What separates the true pelvis from the false pelvis?

iliopectineal line

Muscles of True Pelvis

Piriformis, Obturator internus, Levator ani, and Coccygeus muscles

Piriformis

posterolateral wall muscle of true pelvis

• commonly mistaken for an ovary

Obturator internus

anterolateral pelvic sidewall muscle of true pelvis

Levator ani

pelvic floor (diaphragm) of true pelvis

Coccygeus

posterior pelvic floor (diaphragm) of true pelvis

Bladder

Ureters

crosses the pelvic inlet anterior to the bifurcation of the common iliac arteries

Vagina

• Posterior to urinary bladder and urethra

• Anterior to rectum and anus

Cervix

protrudes into upper portion of vaginal canal forming four archlike recesses

Fornices

blind pockets formed by inner surface of vaginal walls and outer surface of cervix

Uterus

hollow, pear-shaped organ; usually anteflexed and anterverted

Premenarchal Uterine Size

1-3 cm long by 0.5-1 wide

Menarchal Uterine Size

6-8 cm long by 3-5 cm wide

With multiparity (uterine size)

• has given birth two or more times

  • increases size by 1-2 cm

Postmenopausal (uterine size)

3.5-5.5 cm long by 2-3 cm wide

Body of the Uterus is posterior to:

• Vesicouterine pouch

• Bladder

Body of the Uterus is anterior to:

• Rectouterine pouch (Pouch of Douglas)

• Colon and rectum

• Sacrum and coccyx

Body of the Uterus is medial to:

• Broad ligaments

• Uterine vessels

Perimetrium

serous outer layer of uterus (serosa)

Myometrium

muscular middle layer of uterus

Endometrium

inner mucous membrane; surrounds uterine cavity

Round ligament of Uterine

fundus to anterior pelvic sidewalls; holds uterus forward and in anterverted position

Broad ligament of Uterine

lateral aspect of uterus to pelvic sidewall

Mesovarium

posterior fold of broad ligament; encloses ovary

Mesosalpinx

upper fold of broad ligament; encloses fallopian tube

Cardinal ligament

extends across pelvic floor laterally; firmly supports cervix

Uterosacral ligament

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

Suspensory (infundibulopelvic) ligament

extends from lateral aspect of ovary to pelvic sidewall

Ovarian ligament

extends medically from ovary to uterine cornua

Version

the relationship of the cervix to the vagina

Flexion

the relationship of the fundus to the cervix

Anteversion

angle of the vagina/cervix is 90 degrees

Retroversion

angle of the vagina/cervix is less than 90 degrees

Anteflexion

uterine fundus is title anterior towards the cervix

Retroflexion

uterine fundus is titled posterior towards cervix

Dextroversion

tilted right

Levoversion

titled left

Vesicouterine pouch

anterior to fundus between uterus and bladder; Anterior cul-de-sac

Rectouterine pouch

posterior to uterine body and cervix, between uterus and rectum; Posterior cul-de-sac or Pouch of Douglas

Retropubic

anterior to bladder and posterior to symphysis pubis; Space of Retzius

What are the four regions of the Fallopian (uterine) tubes?

Infundibulum, ampulla, isthmus, and interstitial portion

Infundibulum

• Funnel-shaped lateral tube projects beyond broad ligament to overlie ovaries

• “free edge’ of the funnel has fimbriae

Ampulla

widest part of tube where fertilization occurs

Isthmus

hardest part; lies lateral to uterus

Interstitial portion

pierces uterine wall at cornua of uterus

Ovaries

• almond shaped

• attached at posterior aspect of broad ligament by mesovarium

Position of the Ovaries to internal iliac artery and vein

Anterior

Position of the Ovaries to external iliac artery and vein

Medial

Tunica albuginea

a layer of dense connective tissue that covers the cortex of the ovary

Outer cortex

where follicles develop and ovulate an egg cell

Central medulla

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

Ovum

produces reproductive cell

Estrogen

secreted by follicles

Progesterone

secreted by corpus luteum

External iliac arteries

Medial psoas boarder

External iliac veins

Medial and posterior to arteries

Internal iliac arteries

Posterior to ureters and ovaries

Internal iliac veins

Posterior to arteries

Uterine arteries and veins

Between layers of broad ligaments, lateral to uterus

Ovarian arteries

Branch (originate) laterally off aorta, run within suspensory ligaments and anastomose with uterine arteries

Uterine arteries

Branch (originate) off internal iliac artery

Arcuate arteries

Arteries that encircle uterus in outer third of myometrium

Radial arteries

Branches of arcuate arteries that extend from myometrium to base of endometrium

Straight and spiral arteries

Branches of radial arteries that supply zone basalis of endometrium

Uterine veins

drain into internal iliac veins

Ovarian veins

• Right vein drains into IVC directly

• Left vein drains into left renal vein